genetics

Question 1

allele

Answer 1

a different from of the same gene/trait eg) wrinkley seed and round seed. each parent contributes one allele (half their genetic info) . can be dominant or recessive.

Question 2

gene

Answer 2

segment of dna that codes for a specific trait eg) height, colour

Question 3

law of segregation states

Answer 3

each diploid parent creates haploid gametes which receive just one of the pair of alleles of a specific gene. the gamete from male parent fuses with random gamete from female parent to produce a diploid offspring

simply: homologous chromosomes seperate during meiosis (two alleles seperate into each gamete)

Question 4

locus

Answer 4

specific location of chromosome for a gene. (address fro a gene)

Question 5

homozygous vs heterozygous

Answer 5

homozygous: pair of either both dominant or recessive alleles for a gene (AA or aa)

heterozygous: pair of both recessive and dominant gene (Aa)

Question 6

homologous pair

Answer 6

2 chromosomes of same shape/ size that code for the same trait. can have different alleles but still the same trait.

Question 7

law of segregation and meiosis

Answer 7

mendel came up w law before meiosis but it can still be applied to meiosis. First diploid cell replicates the homologous pair to create sister chromatids (meiosis 1) then sister chromatids split and we have 4 chromosomes which then each gamete gets therefore haploid gamete cells.

Question 8

law of independent assortment

Answer 8

states that different pairs of genes seperate individually. they do not move in groups. homologous pairs seperate and the pairs do not follow any other pair they seperate independently.

Question 9

draw both laws in accordance with meiosis

Answer 9

look at notes

Question 10

what stage of meiosis is law of segregation documented in

Answer 10

anaphase 1 (seperating)

Question 11

what stage is law of independent assortment documented in

Answer 11

anphase 1 (serperating)
metaphase 1 (lining up)

Question 12

genotype

Answer 12

type of variant present at a given location (i.e., a locus) in the genome eg) AA, Aa. determines phenotype

Question 13

incomplete dominance

Answer 13

heterozygous individuals show an
intermediate phenotype eg) red and white flower cross to produce pink flower

Question 14

codominance

Answer 14

Codominance allows both alleles to
get expressed when individuals are
heterozygous for the trait (expressed in exponent form)

Question 15

polygenic trait

Answer 15

when multiple genes work together for one trait eg) height and skin colour can be coded for by AABbCc

Question 16

epistasis

Answer 16

one gene depends on another for it to be expressed eg)albino llamas

Question 17

enviornmental influence

Answer 17

eg) sun can change skin colour and diet can change height

Question 18

pleiotropy

Answer 18

a single gene has multiple phenotypic effects
eg) a bald mouse lacks a thymus gland and lacks an immune response

Question 19

monohybrid cross

Answer 19

cross between pure-line parents (homozygous parents), 4 sqaure punnett.practice ine question

Question 20

dihybrid cross

Answer 20

16 square punnett, F1 gen crossed. looks smthn like GgHh practice one question

Question 21

what chromosome are sexlinked traits found on and why

Answer 21

only found on x chromosomes since y is too small and contains less genes than x.

Question 22

what genotype is needed for testcross

Answer 22

test cross is an experimental cross of an individual organism of dominant phenotype but unknown genotype and an organism with a homozygous recessive genotype (and phenotype).

Question 23

which sex are sexlinked conditions expressed more in and why

Answer 23

males since only the x carries the trait and if they have the one allele they have the condition whereas femaleshave two alleles and one dominant in the pair will be expressed even if there is a recessive in the pair. (only for recessive as males and females equally express when affected allele is dominant)

Question 24

pedigree

Answer 24

a family tree of affected and unaffected individuals

Question 25

x-linked recessive pedigree

Answer 25

homozygous recessive individuals are affected and condition can skip generations. female can be a carrier

every affected son has a carrier mother when father is healthy

Question 26

x-linked dominant pedigree

Answer 26

heterozygous and homozygous dominant are affected. condition does not skip generations

males and females equally affected.
if father is affected- all daughters will have it but not sons
if mother is affected-about half of all her children affected

Question 27

autosomal chromosomes vs sex chromosomes

Answer 27

chromosomal pairs 1-22 are autosomes in humans
chromosomal pair 23 is the sex chromosome in humans

Question 28

when do you use multiplictation rule when solving genetic problems and how is it done

Answer 28

when the genes are on different chromosomes/ far apart. u take punnet square of each gene seperately and then multiply broth fractions to find probability.

Question 29

recessive sex linked pedigree

Answer 29

mostly males will be affected and females can be carriers (half shaded)

Question 30

how to check if pedigree is x-linked or autosomal

Answer 30

to check if it is X-linked, you can check if affected son has an affected mom, and if affected daughter has an affected dad.