b6a- reproduction page 3

Question 1

Allele definition

Answer 1

alternate forms of the same gene

Question 2

Dominant meaning

Answer 2

allele that is expressed- shown as a capital letter

Question 3

Recessive meaning

Answer 3

only expressed when paired with another recessive allele- shown by a lower case letter

Question 4

homozygous meaning

Answer 4

pair of the same allele’s eg. BB or bb

Question 5

heterozygous meaning

Answer 5

two different alleles are present eg. Bb

Question 6

genotype meaning

Answer 6

alleles that are present for a particular feature eg, BB, Bb or bb

Question 7

phenotype meaning

Answer 7

physical expression of an allele combination eg. black fur, blonde hair,blue eyes

Question 8

polydactyly cause and symptoms (3)

Answer 8

inheritance of one dominant allele
extra fingers and toes
inherited

Question 9

cystic fibrosis cause and symptoms(2)

Answer 9

inheritance of two recessive allele’s (both parents must be carriers or have CF themselves)
a disorder of cell membranes: makes mucus too thick, causing breathing difficulties, problems in digestive and reproductive system