unit 7, inheritance

Question 1

phenotype?

Answer 1

expression of genes, and its interaction within the environment

Question 2

genotype?

Answer 2

genetic constitution of an organism

Question 3

homozygous?

Answer 3

HH, hh

Question 4

heterozygous?

Answer 4

Hh

Question 5

recessive allele?

Answer 5

only expressed if no dominant is present

Question 6

dominant allele?

Answer 6

will always be expressed in phenotype

Question 7

monohybrid?

Answer 7

genetic inheritance cross of characteristics determined by one gene

Question 8

dihybrid?

Answer 8

genetic inheritance cross for a characterisitc determined by two genes

Question 9

codominant?

Answer 9

both alleles equally expressed in phenotype

Question 10

sex linkage?

Answer 10

gene whose locus is on x chromosome

Question 11

autosomal linkage?

Answer 11

genes located on same chromosome (not a sex chromosome)

Question 12

epistasis?

Answer 12

a gene masks or modifies expression of a different gene at a different locus

Question 13

what is dihybrid? where are the genes located on the chromosome

Answer 13

-inheritance of two pairs of alleles
-gene on one chromosome , one gene on other chromosome

Question 14

what would the ratio of the phenotypes of the offspring be if two heterozygous parents mated?

Answer 14

9:3:3:1

Question 15

what is a parental phenotype?

Answer 15

same phenotypes as parents

Question 16

what are recombinant phenotypes?

Answer 16

-the result of recombination of chromosomes , in sexual reproduction
-e.g.) independent segregation

Question 17

what are autosomes?

Answer 17

not sex chromosomes

Question 18

what is autosomal linkage?

Answer 18

-both genes located on the same chromosome
for example) sweet peas have a chromosome with purple (P) and long (L) and another chromosome with white (p) and short (l)

Question 19

example of sweet peas

how does a white long occur?

Answer 19

• crossing over in prophase 1 during meiosis
• this is unlikely to occur

Question 20

how are genes on a chromosome less likely to split?

Answer 20

if they are close together on a chromosome