Chapter 12 (Genetics)

Question 1

dominant

Answer 1

when an allele overrules the other allele

Question 2

genotype

Answer 2

the genetic constitution of an individual organism

Question 3

phenotype

Answer 3

a set of observable characteristics/traits of an organism

Question 4

homozygous

Answer 4

having 2 identical alleles of a particular gene

Question 5

heterozygous

Answer 5

having 2 different versions of the same gene

Question 6

recessive

Answer 6

a trait expressed only when homozygous, tt

Question 7

gene

Answer 7

basic unit of heredity passed from parent to child

Question 8

allele

Answer 8

variants of genes, providing diversity. determines things like eye color, risk to certain diseases.

Question 9

hybrid

Answer 9

When alleles combined, heterozygous. Ex: SsYy, Pp

Question 10

true breeding

Answer 10

A true breeding is a kind of breeding wherein the parents would produce offspring that would carry the same phenotype. Homozygous. Ex: SSYY, PP, pp

Question 11

Punnett square

Answer 11

used to predict phenotypes/genotypes of 2 organisms’s offspring

Question 12

sex chromosome

Answer 12

A sex chromosome is a type of chromosome involved in sex determination. E.g. X & Y

Question 13

autosomes

Answer 13

A chromosome that isn’t a sex chromosome. We have 22 autosomes.

Question 14

locus

Answer 14

location of specific gene on a chromosome

Question 15

monohybrid cross

Answer 15

cross between 2 homozygous organisms (XX + xx = Xx)

Question 16

dihybrid cross

Answer 16

4x4 Punnett, used for two traits e.g. XxYy x XXyy. remember 9:3:3:1

Question 17

Incomplete dominance

Answer 17

Both alleles of a gene are partially expressed, resulting middle. Ex. RR(Red) x rr(White) = Rr(Pink)

Question 18

Co-dominance

Answer 18

When two alleles of the same gene are dominant & expressed separately. Ex. BB(Black) x WW(White) = BW (Black & White)

Question 19

Law of segregation

Answer 19

During formation of gamete, gene separates from each other: each gamete has one allele for each gene

Question 20

Sex linkage

Answer 20

characteristics/traits influenced by genes carried on sex chromosomes.

Question 21

Law of Independent Assortment

Answer 21

alleles of two/more different genes sorted to gametes independently of another: one gene doesn’t influence other