Genetic Crosses and Heredity

Question 1

somatic cells

Answer 1

body cells or non-sexually reproductive cells

Question 2

gametes

Answer 2

sex cells, are haploid cells capable of fusion

Question 3

fertilisation

Answer 3

is the union of 2 gametes to form a zygote

Question 4

alleles

Answer 4

different (alternate) forms of the same gene

Question 5

genotype

Answer 5

is the genetic make-up of organisms

Question 6

phenotype

Answer 6

physical make up or appearance

Question 7

progeny

Answer 7

the offspring of a cross

Question 8

homozygous

Answer 8

identical alleles e.g bb

Question 9

heterozygous

Answer 9

individual with different alleles e.g Bb

Question 10

incomplete dominance

Answer 10

neither allele masks the expression of the other, produces immediate phenotype

Question 11

autosomes

Answer 11

are chromosomes that don’t determine sexuality

Question 12

dominant

Answer 12

allele that prevents the recessive allele from being expressed

Question 13

recessive

Answer 13

allele that is prevented from being expressed by the dominant allele

Question 14

sex chromosomes

Answer 14

are X and Y chromosomes, xx=female xy=male

Question 15

mendels first law (law of segregation)

Answer 15

inherited traits are controlled by 2 alleles. these alleles separate at gamete formation with each gamete having only one allele

Question 16

mendels second law (law of independent assortment)

Answer 16

either of a pair of alleles is equally likely to combine with either of another pair of alleles when gametes are being formed

Question 17

linkage

Answer 17

means genes are on the same chromosome (contradicts mendels second law)

Question 18

locus

Answer 18

genes position on a chromosome

Question 19

sex linked (x linked)

Answer 19

is controlled by gene on the x chromosome