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158 Cards in this Set
- Front
- Back
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are barr bodies randomly inactivated?
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in humans and most of other mammals, yes.
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hermaphroditism?
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A "true hermaphrodite" is defined as someone with both male gonadal tissue (testes) and female gonadal tissue (ovarian tissue).
Historically, the term hermaphrodite has also been used to describe ambiguous genitalia and gonadal mosaicism in individuals of gonochoristic species, especially human beings, The word hermaphrodite entered the English lexicon in the 15th century, derived from the Greek Hermaphroditos a combination of hermes (male) and aphrodite (female).[2] Recently, the word "intersex" has come into preferred usage for humans, since the word "hermaphrodite" is considered to be misleading and stigmatizing.[3] |
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psudohermaphroditism?
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presence of gonadal tissue of one sex only, but with ambiguous or opposite external genitalia.
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hyperplasia?
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An abnormal increase in the number of cells in an organ or a tissue with consequent enlargement.
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congenital adrenal hyperplasia?
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Congenital adrenal hyperplasia (CAH) refers to any of several autosomal recessive diseases resulting from mutations of genes for enzymes mediating the biochemical steps of production of cortisol from cholesterol by the adrenal glands (steroidogenesis).
Most of these conditions involve excessive or deficient production of sex steroids and can alter development of primary or secondary sex characteristics in some affected infants, children, or adults.[2] |
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primary vs. secondary sex characteristics
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A sex organ, or primary sexual characteristic, as narrowly defined, is any of the anatomical parts of the body which are involved in sexual reproduction and constitute the reproductive system in a complex organism
Secondary sex characteristics are features that distinguish the two sexes of a species, but that are not directly part of the reproductive system. |
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virilization?
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In biology and medicine, virilization refers to the biological development of sex differences, changes that make a male body different from a female body.
Most of the changes of virilization are produced by androgens. Virilization is most commonly used in three medical and biology of gender contexts: prenatal sexual differentiation, the postnatal changes of normal male puberty, and excessive androgen effects in girls or women. |
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aldosterone?
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Aldosterone is a yellow steroid hormone (mineralocorticoid family) produced by the outer-section (zona glomerulosa) of the adrenal cortex in the adrenal gland, and acts on the distal tubules and collecting ducts of the nephron, the functioning unit of the kidney to cause the conservation of sodium, secretion of potassium, increased water retention, and increased blood pressure.
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what is 21-OH-CAH?
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Congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OH CAH), in all its forms, accounts for over 95% of diagnosed cases of congenital adrenal hyperplasia,[1] and "CAH" in most contexts refers to 21-hydroxylase deficiency.
GENERAL DESCRIPTION OF CONGENITAL ADRENAL HYPERPLASIA: Congenital adrenal hyperplasia (CAH) refers to any of several autosomal recessive diseases resulting from mutations of genes for enzymes mediating the biochemical steps of production of cortisol from cholesterol by the adrenal glands (steroidogenesis).[1] CAH is one of the possible underlying synthesis problems in Addison’s disease. Most of these conditions involve excessive or deficient production of sex steroids and can alter development of primary or secondary sex characteristics in some affected infants, children, or adults.[2] in the PPt. it is written that both cortisol and aldosterone are decreased, while androgens increase. WIKI says this is the case only with severe 21-OH-CAH. |
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5-alpha-reductace deficiency?
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5-Alpha-reductase deficiency (5-ARD) is an autosomal recessive intersex condition caused by a mutation of the 5-alpha reductase type 2 gene.[1]
normal function: 5-Alpha-reductase deficiency (5-ARD) is an autosomal recessive intersex condition caused by a mutation of the 5-alpha reductase type 2 gene.[1] The condition affects only genetic males (that is, those with a Y-chromosome) because DHT (5-alpha reductases convert testosterone, the male sex hormone, into the more potent dihydrotestosterone (aka DHT)) has no known role in female development.[2] Individuals with 5-ARD can have normal male external genitalia, ambiguous genitalia, or normal female genitalia. They are born with male gonads, including testicles and Wolffian structures, but usually appear to have female primary sex characteristics. As a consequence, they are often raised as girls, but usually have a male gender identity.[3][4] |
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androgen insensitivity syndrome?
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Androgen insensitivity syndrome (AIS) is a condition that results in the partial or complete inability of the cell to respond to androgens.
AIS is divided into three categories that are differentiated by the degree of genital masculinization: complete androgen insensitivity syndrome (CAIS) is indicated when the external genitalia is that of a normal female, mild androgen insensitivity syndrome (MAIS) is indicated when the external genitalia is that of a normal male, and partial androgen insensitivity syndrome (PAIS) is indicated when the external genitalia is partially, but not fully masculinized. |
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vulva?
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The vulva (from the Latin vulva, plural vulvae. See etymology) is the external genital organs of the female mammal.
The vulva has many major and minor anatomical structures, including the labia majora, mons pubis, labia minora, clitoris, bulb of vestibule, vulval vestibule, greater and lesser vestibular glands, and the opening of the vagina. |
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name the stages of meiosis prophase I
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names of phases, with greek translations:
1 leptotene "thin threads" chromosome condensation 2 zygotene "paired threads" chromosome synapse --> bivalent pachytene "thick threads" diplotene "two threads" diakinesis "moving through" |
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bivalent?
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A bivalent, sometimes referred to as a tetrad, is a pair of associated homologous chromosomes held together by a complex after chromosome replication. During meiosis (the Prophase I stage of Meiosis I), the process of synapsis occurs in which bivalents are formed. Each replicated chromosome is composed of two chromatids.
Bivalents are formed as two homologous chromosomes get close enough for a protein complex (synaptonemal complex) to hold them together. It is at this stage that genetic recombination can occur. Crossing over may occur between these bivalents during meiosis leading to chiasma formation. |
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name all the cells involved in spermatogenesis, and order them from stem cell to terminally specialized cell
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primordial germ cell migrated to gonads
--> repeated mitotic divisions yield spermatogonia primary spermatocyte secondary spermatocyte spermatid --> maturation to spermatozoa |
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what important change occurs in spermatogenesis with the onset of puberty?
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some of the spermatogonia begin to differentiate into primary spermatocytes
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explain important events in oogenesis (in relation to the age of the female)
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4 weeks: meiosis 1 begins and is arrested in dictyotene of prophase 1. primary oocytes do not proceed with meiotic activity until the event of ovulation.
under ovulation, primary oocytes will continue meiosis 1 and yield a polar body no. 2 and a secondary oocyte which enters meiosis 2. the secondary oocyte is arrested at metaphase 2, and will only proceed if fertilized. |
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outline the number of ovarian germ cells in relation to age of females.
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5 month fetus: ca. 7 million
at birth: ca. 2 million puberty: ca. 200 000 no. of primary oocytes ovulated throughout life: ca. 400 |
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do spermatozoa have increased mutation rates as males get older?
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yes.
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dicyotene stage arrest occurs at approx. ...?
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fetal age of 12-20 weeks
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how long does spermatogenesis take?
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approx. 64 days
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Culling?
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Culling is the process of removing animals from a group based on specific criteria. This is done in order either to reinforce certain desirable characteristics or to remove certain undesirable characteristics from the group. For livestock and wildlife, the process of culling usually implies the killing of animals with undesirable characteristics.
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population bottleneck?
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A population bottleneck (or genetic bottleneck) is an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing.[1]
In population bottleneck, survival odds are purely random. The odds of survival for any member of the population is not influenced by inherited genetic advantages.[2] A slightly different sort of genetic bottleneck can occur if a small group becomes reproductively separated from the main population. This is called a founder effect. |
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assortative mating?
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Assortative mating (also called assortative pairing) is the phenomenon where a sexually reproducing organism chooses to mate with individuals that are similar[1][2] (positive assortative mating) or dissimilar (negative assortative mating) to itself in some specific manner. In evolution, these two types of assortative mating have the effect, respectively, of increasing or reducing the range of variation (trait variance), when the assorting is cued on heritable traits. Positive assortative mating, therefore, results in disruptive natural selection, and negative assortative mating results in stabilized natural selection.
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diversifying selection?
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Disruptive selection, also called diversifying selection, describes changes in population genetics in which extreme values for a trait are favored over intermediate values.
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directional selection?
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In population genetics, directional selection is a mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction.
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stabilizing selection?
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Stabilizing or ambidirectional selection, (not the same thing as negative or purifying selection[1] [2]), is a type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value. This is probably the most common mechanism of action for natural selection. Stabilizing selection commonly uses negative selection (a.k.a. purifying selection) to select against extreme values of the character.
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endoreduplication?
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Endoreplication (also referred to as endoreduplication) is replication of the nuclear genome in the absence of cell division, which leads to elevated nuclear gene content and polyploidy.
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functional nullisomy associated with Angelman's syndrome is a result of a nonfunctional .(maternal/paternal???).. allele
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if maternal allele is dysfunctional/absent, AS commences
if paternal alleles are absent on the relevant loci, PWS commences |
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what is preconceptional care?
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definition: An organised and comprehensive program of health care that identifies and reduces a woman's reproductive risks before conception through risk assessment, health promotion, and interventions. Preconception care programs may be designed to include the male partner in providing counseling and educational information in preparation for fatherhood, such as genetic counseling and testing, financial and family planning, etc. This concept is different from prenatal care, which occurs during pregnancy.
[im not sure if this includes looking at risk of genetic diseases... according to genetics dept. it does not include looking at risk of genetic diseases,,,,,, but I think they might be wrong, wouldnt surprise me :/ ] |
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incomplete dominance definition?
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Incomplete dominance occurs when the phenotype of the heterozygous genotype is an intermediate of the phenotypes of the homozygous genotypes.
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how does uniparental disomy occur?
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no clue :(
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explain the difference between inclomplete dominance and codominance
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Incomplete dom.: A red and a white allele gives pink flowers. If it were codominance, you
would see the red and white colors. |
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explain the difference between DUCHENNE and BECKER muscular dystrophy (DMD, BMD).
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Becker muscular dystrophy is related to Duchenne muscular dystrophy in that both result from a mutation in the dystrophin gene (both are x-linked recessive diseases), but in Duchenne muscular dystrophy no functional dystrophin is produced making DMD much more severe than BMD.
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pleiotropy?
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Pleiotropy occurs when a single gene influences multiple phenotypic traits. Consequently, a mutation in a pleiotropic gene may have an effect on some or all traits simultaneously. This can become a problem when selection on one trait favors one specific version of the gene (allele), while the selection on the other trait favors another allele.
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whats the difference between epistasis and dominance?
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Dominance is between alleles of homologous genes; epistasis is "dominance" of one non-homologous allele over another.
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modification?
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not sure
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phenocopy?
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A phenocopy is an individual whose phenotype, under a particular environmental condition, is identical to the one of another individual whose phenotype is determined by the genotype. In other words the phenocopy environmental condition mimics the phenotype produced by a gene.
(im not sure if this includes dying of hair, nose jobs, boob jobs etc,... i think it could be anything as long as it is environmentally induced) |
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character?
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a heritable feature (eye color e.g.)
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trait?
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a specific variant of a character (brown eye color)
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definition of backcrossing?
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Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, in order to achieve offspring with a genetic identity which is closer to that of the parent.
(i think this is the correct definition. in the PPTs, they defined it as "verification of hybrid's heterozygosity") |
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breeding news?
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???? the slides didnt make sense, PPT 1, slide 20.
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testcross?
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In some sources, the "test cross" is defined as being a type of backcross between the recessive homozygote and F1 generation or F2 generation crossed with recessive parent is said to be a Test cross.
ergo, it's a cross between offspring and recessive homozygote parents |
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penetrance?
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Penetrance in genetics is the proportion of individuals carrying a particular variation of a gene (allele or genotype) that also express an associated trait (phenotype).
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define mendel's laws
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1: segregation of alleles
2: independent assortment of alleles 3: Mendel's third law deals with the matter of dominance. (im not 100 % sure if this is completely correct, you'd better crosscheck this with a wise guy) |
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do archea have introns?
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most archaean genes lack introns, although there are many introns in their transfer RNA and ribosomal RNA genes,[100] and introns may occur in a few protein-encoding genes.[101][102]
[check with kovar , he might say something different on this matter] |
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episome?
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An episome is a portion of genetic material that can exist independent of the main body of genetic material (called the chromosome) at some times, while at other times is able to integrate into the chromosome.
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plasmid?
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In microbiology and genetics, a plasmid is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA.[1] They are double-stranded and, in many cases, circular. Plasmids usually occur naturally in bacteria, but are sometimes found in eukaryotic organisms (e.g., the 2-micrometre-ring in Saccharomyces cerevisiae).
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mobilome definition?
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The mobilome is the total of all mobile genetic elements in a genome. Elements that can move within the genome (transposable elements) are the major constituents of the mobilome in eukaryotes. In prokaryotes, however, mobile genetic elements that can move between genomes, like prophages and plasmids, are also an important part of the mobilome.
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mesosome definition?
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Mesosomes are folded invaginations in the plasma membrane of bacteria that are produced by the chemical fixation techniques used to prepare samples for electron microscopy. Although several functions were proposed for these structures in the 1960s, they were recognized as artifacts by the late 1970s and are no longer considered to be part of the normal structure of bacterial cells.
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plasmalemma?
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= cell membrane = plasma membrane.
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which types of structural forms can prokaryotic DNA take?
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circular dsDNA
linear dsDNA there is no difference between bacteria and archea, as far as i know... (not sure though) |
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at how many sites are the bacterial nucleoid bound to the plasma membrane?
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always bound to one site only.
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where on the bacterial nucleoid is replication initiated? is it unidirectional or bidirectional?
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it is bidirectional and originates at a single origin of replication (OriC), which is where the nucleid is bound up to the plasma membrane.
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are prokaryotic cells compartmentalized by internal membrane systems?
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no.
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name the three main types of disorders caused by genetic factors
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single gene disorders
chromosome disorders multifactorial disorders |
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what are the main evolutional eras?
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paleozoic; 500 mill y.a. plants, fungi, animals colonize Pangea (land)
mezosoic: 250 mill y.a. Dinosaurs, first mammals cenozoic: after extinction of dinosaurs. 5 million y.a.: diversion of humans and apes. |
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explain the structural differences between cell walls of bacteria, archea, plants, fungi
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Around the outside of the cell membrane is the bacterial cell wall. Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids.[13] Bacterial cell walls are different from the cell walls of plants and fungi which are made of cellulose and chitin, respectively.
Although not truly unique, the cell walls of Archaea are unusual. Whereas peptidoglycan is a standard component of all bacterial cell walls, all archaeal cell walls lack peptidoglycan,[19] with the exception of one group of methanogens.[1] In that group, the peptidoglycan is a modified form very different from the kind found in bacteria.[19] There are four types of cell wall currently known among the Archaea. One example is pseudopeptidoglycan. |
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plasmalemma?
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= cell membrane
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are nucleoids connected to the plasma membrane?
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yes.
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is transcription and translation directly coupled up in prokaryotes?
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yes! (they dont need to process primary transcripts)
(some archeic genes may be exceptions to this rule, i suppose) |
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replicon?
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A replicon is a DNA molecule or RNA molecule, or a region of DNA or RNA, that replicates from a single origin of replication.
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bacterial conjugation?
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Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells.
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transformation (genetics)?
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In molecular biology transformation is the genetic alteration of a cell resulting from the direct uptake, incorporation and expression of exogenous genetic material (exogenous DNA) from its surrounding and taken up through the cell membrane(s).
[i think the same term is used for the formation of cancer cells...] |
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transduction?
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Transduction is the process by which DNA is transferred from one bacterium to another by a virus[better see in MS Dict].[1]
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structure of sex pilus?
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All pili are primarily composed of oligomeric pilin protein
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fimbriae?
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In bacteriology, a fimbria (plural fimbriae), not to be confused with pili, is a proteinaceous appendage in many Gram-negative and some Gram-positive bacteria that is thinner and shorter than a flagellum. This appendage ranges from 3-10 nanometers in diameter and can be up to several micrometers long. Fimbriae are used by bacteria to adhere to one another and to adhere to animal cells and some inanimate objects. A bacterium can have as many as 1,000 fimbriae. Fimbriae are only visible with the use of an electron microscope.
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virulence?
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Virulence is by MeSH definition the degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host.
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operon?
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An operon is stretch of DNA found in bacteria. This operon controls gene regulation. there are typically three components of an operon: a promoter, operator, and structural gene.
Promotor sequence- is where RNA polymerase binds. Operator sequence- is were a repressor binds and inhibits RNA polymerase from binding. Structural sequence- sequence that codes for the protein. |
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is an operon always rendered transcriptionally inactive when its operator is bound by a regulatory molecule?
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no, we have positive and negative regulation of operons. the molecule binding the operator could be a repressor protein (inhibiting transcription) or an activating factor.
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does the product of the regulatory gene "lacl" upregulate or downregulate the lac-operon?
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negative regulation --> inhibits transcription
when lactose concentration increases, lactose binds the inhibitory factor, and makes it detach from the operator, and thus transcription can commence. b-galactosidase is produced by the operon, and the cell can thus utilize lactose (the enzyme cleaves lactose). |
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a plasmid can carry inserted DNA sequence of a maximum length of ...?
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10 kbp
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polylinker (multiple cloning site/MCS)?
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A multiple cloning site (MCS), also called a polylinker, is a short segment of DNA which contains many (up to ~20) restriction sites - a standard feature of engineered plasmids.[1] Restriction sites within an MCS are typically unique, occurring only once within a given plasmid. MCSs are commonly used during procedures involving molecular cloning or subcloning. Extremely useful in biotechnology, bioengineering, and molecular genetics, MCSs let a biotechnologist insert a piece of DNA or several pieces of DNA into the region of the MCS. This can be used to create transgenic organisms, also known as genetically modified organisms (GMOs).
[i think polylinkers are artificially built] |
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express vector?
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strong promotor and polylinker, encoding sequence
[words taken straight from PPTs] |
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selectable marker?
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A selectable marker is a gene introduced into a cell, especially a bacterium or to cells in culture, that confers a trait suitable for artificial selection.
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vector (genetics)?
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In molecular biology, a vector is a DNA molecule used as a vehicle to transfer foreign genetic material into another cell. The four major types of vectors are plasmids, viruses, cosmids, and artificial chromosomes. Common to all engineered vectors are an origin of replication, a multicloning site, and a selectable marker.
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DNA construct?
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A DNA construct (stress on first syllable) is an artificially constructed segment of nucleic acid that is going to be "transplanted" into a target tissue or cell.
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in silico?
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In silico is an expression used to mean "performed on computer or via computer simulation."
e.g. many BACs are sequenced, and the parts are rearranged in silico, resulting in the genomic sequence of the organism. like in the human genome project. |
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cosmid?
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A cosmid, first described by Collins and Hohn in 1978, is a type of hybrid plasmid (often used as a cloning vector) that contains cos sequences, DNA sequences originally from the Lambda phage.
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auxotrophy?
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Auxotrophy (Gr. αὐξάνω "to increase"; τροφιά "nurishment") is the inability of an organism to synthesize a particular organic compound required for its growth (as defined by IUPAC).
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YAC?
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A yeast artificial chromosome (YAC) is a vector used to clone DNA fragments larger than 100 kb and up to 3000 kb. YACs are useful for the physical mapping of complex genomes and for the cloning of large genes
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transgenesis?
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Transgenesis is the process of introducing an exogenous gene – called a transgene – into a living organism so that the organism will exhibit a new property and transmit that property to its offspring. Transgenesis can be facilitated by liposomes, plasmid vectors, viral vectors, pronuclear injection, protoplast fusion, and ballistic DNA injection.
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do mitochondria have nucleosomes?
do they have introns? |
no
no |
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N-Formylmethionine (fMet)?
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N-Formylmethionine (fMet) is a proteinogenic amino acid found in Bacteria and related Prokaryotic organelles. It is a derivative of the amino acid methionine in which a formyl group has been added to the amino group. It is specifically used for initiation of protein synthesis, and may be removed after.
fMet plays a crucial part in the protein synthesis of bacteria, mitochondria and chloroplasts. It is not used in cytosolic protein synthesis of eukaryotes, where eukaryotic nuclear genes are translated. It is also not used by Archaea. In the human body, fMet is recognized by the immune system as foreign material and stimulates the body to fight against potential infection. |
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how many separate DNA molecules comprise the human mitochondrial genome?
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one or several circular DNA molecules. (ssDNA)
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how many genes are encoded by the human mitochondrial genome?
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37 GENES: 13 for subunits of respiratory complexes I, III, IV and V, 22 for mitochondrial tRNA (for the 20 standard amino acids, plus an extra gene for leucine and serine), and 2 for rRNA.[62] One mitochondrion can contain two to ten copies of its DNA.[63]
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are there repetitive DNA sequences in mitochondrial genome?
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i think there are no repeats, (if there are, then there is very little of them)
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is the genetic code of mitochondria identical to nucleus?
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no, 4 triplets are different (according to genetics slides)
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mitochondria replicate during which part of the cell cycle?
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interphase
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how often do we get mitochondrial DNA mutations in comparison to nuclear DNA mutations?
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10x more common in mitochondria
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does prokaryotic and mitochondrial genomes contain histones`?
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no.
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heteroplasmy vs. homoplasmy?
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the mixture of normal and mutant mtDNA = heteroplasmy
presence of only normal or only mutant mtDNA = homoplasmy |
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name, and give a brief outline of, two, mitochonrial diseases / types of mitochondrial diseases, mentioned in the PPT.
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Leber’s hereditary optic neuropathy (LHON) or Leber optic atrophy is a mitochondrially inherited (mother to all offspring) degeneration of retinal ganglion cells (RGCs) and their axons that leads to an acute or subacute loss of central vision; this affects predominantly young adult males.
Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes – abbreviated to MELAS – is one of the family of mitochondrial cytopathies, which also include MERRF, and Leber's Hereditary Optic Atrophy. It was first characterized under this name in 1984. |
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are chloroplasts always green?
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no, not if photosyntheis-responsiple genes are inactivated.
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gene therapy
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Gene therapy is the insertion, alteration, or removal of genes within an individual's cells and biological tissues to treat disease.
the genetic changes induced will not be passed on to children of the treated individual (unless germ cells are treated). |
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SCID
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Severe combined immunodeficiency (SCID), (also known as "Alymphocytosis," "Glanzmann–Riniker syndrome," "Severe mixed immunodeficiency syndrome," and "Thymic alymphoplasia"[1]) is a genetic disorder in which both "arms" (B cells and T cells) of the adaptive immune system are impaired due to a defect in one of several possible genes. SCID is a severe form of heritable immunodeficiency. It is also known as the "bubble boy" disease because its victims are extremely vulnerable to infectious diseases and some of them, such as David Vetter, become famous for living in a sterile environment
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hh antigen system?
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hh is a rare blood group also called Bombay Blood group. Individuals with the rare Bombay phenotype hh (recessive homozygotes) do not express H antigen (also called substance H) (the antigen which is present in blood group O)
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which of the ABO group phenotypes are most common in the world population?
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O phenotype (antigen H). according to genetics slides, this is the most common group in caucasians, africans, asians and native americans.
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ontogeny?
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Ontogeny (also ontogenesis or morphogenesis) describes the origin and the development of an organism - for example: from the fertilized egg to mature form.
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what three classes of mutations do we distinguish between?
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genome (chromosome segregation error)
chromosome (structural abberation) gene |
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euploid?
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an exact multiple of the haploid chromosome number
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elongation mutation?
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change of stop-encoding triplet into AA-encoding triplet
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microsatelite?
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Microsatellites, also known as Simple Sequence Repeats (SSRs) or short tandem repeats (STRs), are repeating sequences of 1-6 base pairs of DNA.[
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trinucleotide disorders?
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Trinucleotide repeat disorders (also known as trinucleotide repeat expansion disorders, triplet repeat expansion disorders or codon reiteration disorders) are a set of genetic disorders caused by trinucleotide repeat expansion, a kind of mutation where trinucleotide repeats in certain genes exceeding the normal, stable, threshold, which differs per gene. The mutation is a subset of unstable microsatellite repeats that occur throughout all genomic sequences. If the repeat is present in a healthy gene, a dynamic mutation may increase the repeat count and result in a defective gene.
Trinucleotide repeats are sometimes classified as insertion mutations[1][2] and sometimes as a separate class of mutations.[3] |
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penetrance?
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The proportion of individuals possessing a disease-causing genotype who express the disease phenotype – in a population
When this proportion is less than 100% the disease genotype is said to have reduced or incomplete penetrance |
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placenta?
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The placenta is an organ that connects the developing fetus to the uterine wall to allow nutrient uptake, waste elimination, and gas exchange via the mother's blood supply
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what are the mullerian (paramesonephric) ducts. how do they develop in
males? females? |
Müllerian ducts (or paramesonephric ducts) are paired ducts of the embryo that run down the lateral sides of the urogenital ridge and terminate at the Müllerian eminence in the primitive urogenital sinus. In the female, they will develop to form the Fallopian tubes, uterus, cervix, and the upper third of the vagina; in the male, they are lost. These ducts are made of tissue of mesodermal origin.
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anlage?
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In embryology, anlage is the primordium, the initial clustering of embryonic cells that serves as a foundation from which a body part or an organ develops.
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what is the wolffian (mesonephric) duct? how does it develop in males? in females?
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The mesonephric duct, (also known as Wolffian duct, archinephric duct, Leydig's duct and nephric duct ) is a paired organ found in mammals including humans during embryogenesis.
It connects the primitive kidney Wolffian body (or mesonephros) to the cloaca and serves as the anlage for certain male reproductive organs. in the absence of sufficient testosterone (female development) exposure, it regresses and leaves behind artifacts (gardener's duct or gardener's cyst). in males, its derivatives include seminal vesicles, epididymis, ejaculatory duct, ductus deferens. mneumonic: Gardener's SEED |
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SRY gene role in sexual differentiation?
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SRY (Sex-determining region Y) is a sex-determining gene on the Y chromosome in the therians (placental mammals and marsupials).[1]
This intronless gene encodes a transcription factor that is a member of the SOX (SRY-like box) gene family of DNA-binding proteins. This protein is the therian testis determining factor (TDF), referred to as the sex-determining region Y protein or SRY protein which initiates male sex determination. Mutations in this gene give rise to XY females with gonadal dysgenesis (Swyer syndrome); translocation of part of the Y chromosome containing this gene to the X chromosome causes XX male syndrome.[2] |
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Anti-mullerian hormone (mullerian inhibiting substance)?
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Anti-Müllerian hormone also known as AMH is a protein that, in humans, is encoded by the AMH gene.[1] It inhibits the development of the Müllerian ducts (paramesonephric ducts) in the male embryo.[2] It has also been called Müllerian inhibiting factor (MIF), Müllerian-inhibiting hormone (MIH), and Müllerian-inhibiting substance (MIS).
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gubernaculum?
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As the scrotum and labia majora form in males and females, respectively, the gubernaculum aids in the descent of the gonads (both testes and ovaries).
he paired Gubernacula are embryonic structures which begin as undifferentiated mesenchyme attaching to the caudal end of the gonads (testes in males and ovaries in females). The testes descend to a greater degree than the ovaries and ultimately pass through the inguinal canal. The gubernaculum is present only during the development of the urinary and reproductive organs, being replaced by distinct vestiges in males and females. |
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what is the difference between pseudhermaphroditism and hermaphroditism?
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hermaphroditism – presence of
both ovarian and testicular tissue → the genitalia are ambiguous pseudohermaphroditism – presence of gonadal tissue of only one sex but with ambiguous or opposite external genitalia |
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explain the difference between hyperplasia and hypertrophy.
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Hyperplasia (or "hypergenesis") means increase in number of cells/proliferation of cells. It may result in the gross enlargement of an organ and the term is sometimes mixed with benign neoplasia/ benign tumor.
Hyperplasia is a common preneoplastic response to stimulus. Microscopically cells resemble normal cells but are increased in numbers. Sometimes cells may also be increased in size (hypertrofia).[1] Hyperplasia is different from hypertrophy in that the adaptive cell change in hypertrophy is an increase in cell size, whereas hyperplasia involves an increase in the number of cells. |
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what is the difference between a population bottleneck (bottleneck effect) and the founder-effect?
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A population bottleneck (or genetic bottleneck) is an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing.[1]
In population bottleneck, survival odds are purely random. The odds of survival for any member of the population is not influenced by inherited genetic advantages.[2] A slightly different sort of genetic bottleneck can occur if a small group becomes reproductively separated from the main population. This is called a founder effect. |
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structure of spermatozoon
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The sperm cell consists of a head, a midpiece and a tail. The head contains the nucleus with densely coiled chromatin fibres, surrounded anteriorly by an acrosome, which contains enzymes used for penetrating the female egg. The midpiece has a central filamentous core with many mitochondria spiralled around it, used for ATP production for the journey through the female cervix, uterus and uterine tubes. The tail or "flagellum" executes the lashing movements that propel the spermatocyte
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spermatium?
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non-motile sperm
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which 3 essential factors do sperm provide to oocytes through fertilization?
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During fertilization, the sperm provides three essential parts to the oocyte: (1) a signalling or activating factor, which causes the metabolically dormant oocyte to activate; (2) the haploid paternal genome; (3) the centrosome, which is responsible for maintaining the microtubule system.[3]
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spermiogenesis?
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Spermiogenesis is the final stage of spermatogenesis, which sees the maturation of spermatids into mature, motile spermatozoa.
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definition of species?
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group of individuals whose individuals are able to interbreed and produce FERTILE offspring.
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definition of population?
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localized group of individuals belonging to the same species.
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what is the result of of hardy weignberg equilibrium?
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no evolution occuring.
genetics dept. lists the following conditions for there to be a hardy-weignberg equilibrium, but wikipedia also includes meiotic drive very large population no migration no net mutations random mating no natural selection |
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meiotic drive?
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All nuclear genes in a given diploid genome cooperate because each allele has an equal probability of being present in a gamete. This fairness is guaranteed by meiosis. However, there is one type of gene, called a segregation distorter, that "cheats" during meiosis or gametogenesis and thus is present in more than half of the functional gametes.
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what is a chimera?
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A chimera or chimaera is an animal that has two or more different populations of genetically distinct cells that originated in different zygotes involved with sexual reproduction; if the different cells emerged from the same zygote, it is called a mosaic. Chimeras are formed from four parent cells (two fertilized eggs or early embryos fused together). Each population of cells keeps its own character and the resulting animal is a mixture of tissues. Chimeras are typically seen in non-human zoology, but also discovered to a rare extent in humans.
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endoreduplication?
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Endoreplication (also referred to as endoreduplication) is replication of the nuclear genome in the absence of cell division, which leads to elevated nuclear gene content and polyploidy.
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hydatidiform mole?
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Hydatiforme mole (complete) = dispermy or duplication of a sperm in enucleated ovum
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ovarial teratoma?
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ovarial teratoma = duplication of chromosomes and division of unfertilized ovum
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what is the difference between the (if any,) result of a meiotic nondisjunction and a mitotic nondisjunction?
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meiotic nondisjunction: aneuploidy in offspring
mitotic nondisjunction: mosaic organism |
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karyotype?
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A karyotype is the number and appearance of chromosomes in the nucleus of a eukaryotic cell.
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which monosomies are compatible with life?
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only monosomy 45,X
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are meiotic nondisjunctions maternal or paternal, in most cases?
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maternal ones are most common, and get exceedingly commonplace as maternal age increases. maternal age above e.g. 35 results in higher risk of nondisjunction.
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what happens if, in a zygote, the female pronucleus is replaced by a male one, prior to fusion of the pronuclei?
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androgenesis. the zygote rarely implants into the endometrium, and never develops beyond the 12-somite stage. placental tissues develop many cysts (hydatidiform mole)
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what happens if, in a zygote, the male pronucleus is replaced by a female one, prior to fusion of the pronuclei?
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poor development of extraembryonic tissues. development will stop at the 40-somite stage. causes ovarial teratoma with many different types of tissues.
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teratoma?
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A teratoma is an encapsulated tumor with tissue or organ components resembling normal derivatives of all three germ layers.
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trisomic rescue?
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Trisomic rescue (also known as trisomy rescue or trisomy zygote rescue) a genetic phenomenon in which a fertilized ovum containing three copies of a chromosome loses one of these chromosomes to form a normal, diploid chromosome complement. If both of the retained chromosomes came from the same parent, then uniparental disomy results.
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isodisomy?
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A type of uniparental disomy in which two copies of the same chromosome are inherited from one parent, with resultant homozygosity at all gene loci on the chromosome.
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for the genes affected in PWS, is it the maternal or the paternal genes, that are usually expressed?
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normally, the paternal genes are expressed.
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for the genes affected in AS, is it the maternal or the paternal genes, that are usually expressed?
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normally, the maternal genes are expressed.
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can genomic imprinting errors cause cancers?
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yes, if they affect tumor supressor or protooncogenes.
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does histone deacetylation render the associated DNA more accessible to transcription?
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no.
Acetylation brings in a negative charge, acting to neutralize the positive charge on the histones and decreases the interaction of the N termini of histones with the negatively charged phosphate groups of DNA. As a consequence, the condensed chromatin is transformed into a more relaxed structure which is associated with greater levels of gene transcription proteins. think of it like this: more acetylation = more transcription more methylation = less transcription |
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is mitotic crossover (mitotic recombination) possible?
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Yes. Mitotic crossover is a rare type of genetic recombination that may occur in some types of somatic cells during mitosis.
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will loss of the p-arm of an acrocentric chromosome cause harm to the organism?
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No.
In an acrocentric chromosome the p arm contains genetic material including repeated sequences such as nucleolar organizing regions, and can be translocated without significant harm, as in a balanced Robertsonian translocation. |
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is mitotic crossover (mitotic recombination) possible?
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Yes. Mitotic crossover is a rare type of genetic recombination that may occur in some types of somatic cells during mitosis.
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where on the human chromosomes can we find nucleolus organizer regions (NORs)?
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On the short arms of chromosomes 13, 14, 15, 21 and 22 (the acrocentric chromosomes). Loss of two of these regions due to a robertsonian translocation i not harmful. (perhaps u can loose even more, im not sure)....
general info: The nucleolus organizer region (NOR) or nucleolar organizer is a chromosomal region around which the nucleolus forms. This region is the particular part of a chromosome that is associated with a nucleolus after the nucleus divides. The region contains several tandem copies of ribosomal RNA genes.[1] In humans, the NOR contains genes for 5.8S, 18S, and 28S rRNA clustered on the short arms of chromosomes 13, 14, 15, 21 and 22 (the acrocentric chromosomes). |
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will loss of the p-arm of an acrocentric chromosome cause harm to the organism?
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No.
In an acrocentric chromosome the p arm contains genetic material including repeated sequences such as nucleolar organizing regions, and can be translocated without significant harm, as in a balanced Robertsonian translocation. |
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where on the human chromosomes can we find nucleolus organizer regions (NORs)?
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On the short arms of chromosomes 13, 14, 15, 21 and 22 (the acrocentric chromosomes). Loss of two of these regions due to a robertsonian translocation i not harmful. (perhaps u can loose even more, im not sure)....
general info: The nucleolus organizer region (NOR) or nucleolar organizer is a chromosomal region around which the nucleolus forms. This region is the particular part of a chromosome that is associated with a nucleolus after the nucleus divides. The region contains several tandem copies of ribosomal RNA genes.[1] In humans, the NOR contains genes for 5.8S, 18S, and 28S rRNA clustered on the short arms of chromosomes 13, 14, 15, 21 and 22 (the acrocentric chromosomes). |
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tandem repeats?
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Tandem repeats occur in DNA when a pattern of two or more nucleotides is repeated and the repetitions are directly adjacent to each other. [1]
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tandem repeats?
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Tandem repeats occur in DNA when a pattern of two or more nucleotides is repeated and the repetitions are directly adjacent to each other. [1]
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can translocations cause cancer?
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yes, translocations are very likely to cause cancer. e.g. if a protooncogene is moved to another place in the genome with much higher transcriptional activity.
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what sort of disorder is fragile X syndrome?
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trinucleotide repeat disorder.
(too many CGG repeats result in a failure to express the protein coded by the FMR1 gene, which is required for normal neural development.) |
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what's the difference between the following DNA repair mechanisms?
base excision repair (BER) nucleotide excision repair (NER) mismatch repair (MMR) ? |
BER: repair of 1 nucleotide
NER: repair of 2-30 nucleotides MMR: corrects mispaired nucleotides. |
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what is a clastogen?
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An agent or process giving rise to or inducing disruption or breakages of chromosomes.
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how can we determine the amount of radiation a set of chromosomes has been exposed to?
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the frequency of dicentric chromosomes correlates with the radiation dose.
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briefly describe the Ames test.
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to test the mutagenic potential of a compound, an auxotrophic strain of bacteria is incubated in a dish devoid of an essential nutrient (e.g. histidine).
bacteria that manage to proliferate in the dish have undergone mutations, so the number of surviving colonies correlates with the mutagenicity of the compound tested. |
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biomarker?
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A biomarker, or biological marker, is in general a substance used as an indicator of a biological state
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define teratology.
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Teratology is the study of abnormalities of physiological development. It is often thought of as the study of birth defects, but it is much broader than that, taking in other developmental stages, such as puberty; and other life forms, such as plants.
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anamnesis?
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doctor asks patient about detailed info on disorders in his/her family
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what kind of mendelian inheritance corresponds to cystic fibrosis?
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AR
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