inheritance

Question 1

what is an allele

Answer 1

different forms of the same gene

Question 2

dominant

Answer 2

allele of a gene that is always expressed in the heterozygous genotype

Question 3

recessive

Answer 3

allele that is not expressed in the phenotype when a dominant allele of the gene is present

Question 4

genotype

Answer 4

alleles an organism has for a certain characteristic eg:BB, homozygous dominant

Question 5

phenotype

Answer 5

how a gene is expressed. the ‘appearance’ of an organism resulting from its genotype

Question 6

homozygous

Answer 6

genotype with the same alleles of a gene, eg: AA or aa

Question 7

heterozygous

Answer 7

genotype with different alleles of a gene, eg:Aa

Question 8

codominant

Answer 8

if 2 alleles are expressed in the same phenotype- they are called codominant

Question 9

polygenic inheritance

Answer 9

when many characteristics are controlled by 2 or more genes working together’

Question 10

what is an example of polygenic inheritance

Answer 10

human skin colour

Question 11

why do the offspring from sexual reproduction vary genetically

Answer 11

huge variation in gametes, so it is random in which fertilisation takes place (RANDOM FERTILISATION)

Question 12

list three ways how twins are identical caused by genetics

Answer 12

-eye colour
-DNA
-height

Question 13

list three ways how twins are identical caused by environment

Answer 13

-personality
-weight
-hair colour

Question 14

what is the shape of DNA

Answer 14

double helix shape
-made of subunits and nucleotides