SPEC POINT 2.13

Question 1

What is a gene?

Answer 1

sequence of bases/nucleotides in DNA that codes for the primary structure/amino acid sequence/polypeptide

Question 2

What are alleles?

Answer 2

Alternative forms of a gene occupying the same locus on a chromosome

Question 3

What is genotype?

Answer 3

All of the alleles an organism carries on it’s chromosomes

Question 4

What is phenotype?

Answer 4

The observable characteristics of an organism

Question 5

What do homozygous and hetereozygous mean?

Answer 5

Homozygous - Pair of alleles that produce a characteristic that are the same, e.g. HH or hh
Hetereozygous - Pair of alleles that will produce a characteristic that will be different e.g. Hh

Question 6

What is the difference between a dominant and recessive allele?

Answer 6

Dominant - always expressed

Recessive - only expressed if no dominant allele is present

Question 7

What is the meaning of the term recessive allele?

Answer 7

Both alleles must be present in order for recessive phenotype to be expressed.
AND different form of a gene/same locus/different base sequence

Question 8

What is incomplete dominance?

Answer 8

Where a trait from a dominant allele is not completely expressed over the recessive allele trait (it ‘dilutes’ it)

Question 9

What is monohybrid inheritance?

Answer 9

The inheritance of a characteristic controlled by a single gene

Question 10

What is the use of pedigree diagrams?

Answer 10

Family pedigree diagrams can be used to trace the pattern of inheritance of a specific trait, e.g. a genetic disorder, through generations of a family

Question 11

What is the use of the chi squared test?

Answer 11

Can determine if there is a significant difference between observed and expected results in an experiment