Genetics C level

Question 1

Define a gene

Answer 1

A gene is a sequence of DNA that codes for a protein and therefore determines a trait.

Question 2

Define and give an example of an allele

Answer 2

An allele is one or two(or more) versions of a gene at matching positions on homologous chromosomes.

Question 3

Describe the principle of dominance as well as necessary conditions for an organism to show a recessive characteristic

Answer 3

An organism with a dominant allele for a trait will always show the dominant characteristic. An organism with a recessive allele will only show the recessive characteristic if the dominant allele for the trait is not present.

Question 4

Define genotype

Answer 4

Genotype is the allele combination(genetic makeup) that an organism has for a trait.

Question 5

Define phenotype

Answer 5

Phenotype is any observable characteristic of an organism such as its physical appearance or behavior.

Question 6

Define homozygous

Answer 6

Homozygous is having two identical alleles for a trait

Question 7

Define heterozygous

Answer 7

Heterozygous as having two different alleles for a trait.

Question 8

Define gamete

Answer 8

a sex cell used in sexual reproduction, sperm or egg.