Genetics

Question 1

genotype

Answer 1

the combination of alleles a person has

Question 2

alleles

Answer 2

the variants of a particular gene

Question 3

phenotype

Answer 3

the expression of a genotype

Question 4

the genotype interacts with the __________________ to produce the phenotype

Answer 4

external environment

Question 5

sources of genetic variability

Answer 5

genetic recombination (random segregation & crossing over)
mutation- change in DNA sequence

Question 6

deme

Answer 6

local population that interbreeds

Question 7

gene pool

Answer 7

all the genetic information in a breeding population

Question 8

reproductive isolation

Answer 8

mechanism that prevents two populations from interbreeding

Question 9

species

Answer 9

groups of reproductively isolated organisms

Question 10

reproductive isolation is not always

Answer 10

absolute

ie. hybrids can happen

Question 11

incomplete reproductive isolation

Answer 11

produces living but not fertile offspring

Question 12

polygenic inheritance is not

Answer 12

mendelian

Question 13

polygenic traits are also known as

Answer 13

continuous traits

Question 14

continuous traits are governed by…

Answer 14

alleles at two or more loci, and each locus has some influence on the phenotype

Question 15

examples of polygenic traits

Answer 15

hair, skin and eye colour

Question 16

skin coloration is determine by pigment produced by special cells called…

Answer 16

melanocytes

Question 17

EVERYONE has the same number and distribution of

Answer 17

melanocytes

Question 18

the amount of melanin produced determines

Answer 18

how dark or light the skin will be

Question 19

melanin production is influenced by

Answer 19

interactions between several different loci

Question 20

how can melanin production vary

Answer 20

in amount produced and pattern it is produced in (ie. freckles)

Question 21

factors that influence human skin colour

Answer 21

genetics and stress from solar radiation

Question 22

why are skin colours darker near the equator

Answer 22

melanin protects from solar radiation

Question 23

why is skin colour lighter farther from the equator

Answer 23

melanin prevents vitamin D synthesis

Question 24

discontinuous distribution of mendelian traits

Answer 24

frequencies are easily counted, no blending occurs

Question 25

continous expression of a polygenic trait

Answer 25

frequencies can’t be counted easily

ie. height, theres no set distinct phenotypes but instead a range

Question 26

what traits cause more of the observable phenotypic variation in humans and serve as a basis for racial classification

Answer 26

polygenic traits

Question 27

more examples of polygenic traits

Answer 27

stature, shape of face, fingerprints

Question 28

Rh- mother with Rh+ baby

Answer 28

Rh antigens from developing fetus can enter mothers blood during delivery causing the mother to produce anti Rh antibodies

if this woman becomes pregnant with an Rh+ fetus, the anti rh antibodies will cross the placenta and damage fetal RBCs

Question 29

Rh- is

Answer 29

recessive