quiz 2 deck

Question 1

Explain the difference between biological sex and gender

Answer 1

sex of an individual is determined based on its phenotype

gender is not the same as sex
-one’s gender does not need to consider with ones’s biological sex

Question 2

Describe the major sex-chromosome sex determining systems, including XX-XO, XX-XY, and
ZZ-ZW systems

Answer 2

FEMALE MALE
xx xo
xx xy
zw zz

Question 3

Explain how sex is determined in the genic sex-determining system

Answer 3

Sex determination is determined by individual genes
In chromosomal sex determination the sex chromosomes look different in males and females

in genetic sex determination: there are no obvious differences in the chromosomes of males and females (cant tell M or F)

sex is determined by genes, but the chromosomes of males and females are indistinguishable
In genic the chromosomes also look different in male and females

Question 4

Describe environmental sex determination

Answer 4

sexual phenotype affected by temeprature during embryonic development
Sex chromosomes determine sex, but environment overrides this
sequential hermaphroditism: each individual can be both male and female, but not at the same time

Question 5

Explain how sex in humans is determined

Answer 5

sex is inherited like other genetically determined characteristics , presence of sry gene

xx and xy

Question 6

Describe several sex chromosome anomalies in humans.

Answer 6

Poly x females (mostly fertile)
xyy males (generally normal physical characteristics
Klinefelter syndrome: xxy, xxxy, xxxxy,xxyy, MALE. at least 1 y chromosome and multiple x, sterile
turner syndrome xo (female, single x chromosome, sterile)

Question 7

Explain the origin of androgen insensitivity syndrome

Answer 7

Female in apperance with xy chromsomes caused by defective androgen receptor
cells do no respond to testerone

Question 8

List the characteristics of Y-linked traits

Answer 8

Inherited from the father and is displayed in all male offspring, not female

Question 9

predict the number of Barr bodies present in cells with different complements of sex
chromosomes

Answer 9

Random inactivation of one x chromosome in cells of females (barr bodies)
xxy -1
xxyy-1
xxxy-2
xxxxy-3
xxx-2
xxxx-3
xxxxx-4

Question 10

Describe the molecular mechanism by which random inactivation of X chromosomes occurs

Answer 10

all somatic cells that descend from inactive cell remain inactive (why they can be passed on)
it is a type of epigenetics?

Question 11

Explain the differences between complete, incomplete, and codominance.

Answer 11

Complete: phenotype of the herteozygote is the same as the phenotype of one of the homozygotes

Incomplete:phenotype of the heterozygote is the intermediate between the phenotypes of the two homozygotes

codominance: phenotype of the heterozygote includes the phenotypes of both homozygotes

Question 12

Predict the proportions of offspring produced when penetrance is incomplete

Answer 12

Incomplete penetrance: the genotype does not alwasy produce the expected phenotype

Question 13

Describe the difference between incomplete penetrance and variable expressivity

Answer 13

Expressivity: the degree to which a trait is expressed

Incomplete penetrance: the genotype does not always produce the expected phenotype

Polydactly example:
incomplete penatrance: polydactly trait caused by a dominant allele children has polydactly but parents don’t although he should, gene for polydactly is not fully penetrant

Expressivity: polydactly exhibit variable expressivity; some ppl have extra toes while some have extra skin

Question 14

Explain how genic interaction differs from dominance

Answer 14

Dominance is an interaction between alleles at a single locus, gene interaction happens at different loci

Question 15

Explain why one might want to carry out a complementation test.

Answer 15

In instances when two parent organisms each carry two mutant genes in a homozygous recessive state, causing the recessive trait to be expressed, the complementation test can determine whether the recessive trait will be expressed in the next generation.

Question 16

Recognize the characteristics of cytoplasmically inherited traits (sperm blows shit out of proportion)

Answer 16

mitochondira
typically all its cytoplasmic organelles and thus cytoplasmic genes , come from only on gamete
egg usually contribute cytoplasmic organelles and sperm usually contributes only nuclear genes

Question 17

Describe the differences between sex-influenced characteristics, sex-limited characteristics,
cytoplasmically inherited traits, genetic maternal effect, genomic imprinting, and anticipation

Answer 17

Sex-influenced characteristics: These are traits that are influenced by sex hormones, but the expression of the trait is not limited to one sex. For example, baldness is influenced by the male hormone testosterone, but it can also occur in females.

Sex-limited characteristics: These are traits that are expressed in only one sex. For example, the ability to lactate is limited to females.

Cytoplasmically inherited traits: These are traits that are inherited through the cytoplasm of the cell, rather than through the nuclear DNA. Mitochondrial DNA is an example of cytoplasmically inherited genetic material.

Genetic maternal effect: This is a type of inheritance where the phenotype of the offspring is determined by the genotype of the mother. In this case, the mother’s genes determine the phenotype of the offspring, regardless of the offspring’s own genotype.

Genomic imprinting: This is a phenomenon where the expression of a gene depends on whether it was inherited from the mother or the father. In genomic imprinting, certain genes are silenced or expressed depending on which parent they were inherited from.

Anticipation: This is a phenomenon where the severity or age of onset of a genetic disorder increases in successive generations. For example, in Huntington’s disease, the age of onset of symptoms tends to decrease in each generation, resulting in an earlier onset of symptoms in the offspring.

Overall, these genetic concepts illustrate the complex nature of inheritance and how different factors can influence the expression of traits and disorders.

Question 18

Explain how environmental factors affect the expression of traits

Answer 18

temperature and ph sensitive allele

Question 19

Explain the difference between polygeny and pleiotropy

Answer 19

Polygeny refers to the situation where a trait or disorder is determined by the combined effect of multiple genes. In contrast, pleiotropy refers to the situation where a single gene affects multiple traits or functions. Polygeny results in a continuous range of variation in the trait, while pleiotropy often results in a complex pattern of inheritance, as the same gene can affect multiple traits in different Pleiotropy often results in a complex pattern of inheritance, as the same gene can affect multiple traits in different ways.

Question 20

Explain what a polygenic characteristic is.

Answer 20

a part of a continous characteristic: characteristics that display a large number of possible phenotypes that are not easily distinguished. characteristics encoded by genes at many loci.
Polygeny refers to the situation where a trait or disorder is determined by the combined effect of multiple genes. In other words, the phenotype of the trait is influenced by the interaction of several genes. Polygeny often results in a continuous range of variation in the trait, rather than distinct categories.