B5.1 Inheritance

Question 1

Explain the function of genes

Answer 1

Genes determine the production of proteins.

This controls the development of different characteristics and how an organism functions.

Question 2

What is the definition of allele

Answer 2

Allele is a variation of a gene that gives a different form of a characteristic.

Question 3

Describe the difference between the genotype and phenotype of an organism.

Answer 3

Phenotype is the characteristic of a species.

Genotype is the genes and alleles that an organism has

Question 4

What is a mutation?

Answer 4

Mutation is when the bases of DNA is altered randomly, it can be inherited.

Question 5

Explain how mutations can lead to a change in the phenotype of an organism? (6 marks)

Answer 5

Mutations change the sequence of bases in DNA = genetic variant.
Alter the sequence of amino acids coded for by a gene -> change structure of protein
Affect the proteins ability to perform its function leading to change in phenotype.

Mutations can also affect non coding DNA.
This can affect whether genes are expressed or not.
Mutations stop the transcription of mRNA
Mutations prevent a protein from being expressed , it can have a small/ large effect on the phenotype.

Question 6

What organisms did Mendel use in his work?

Answer 6

Pea plants

Question 7

What do we now call mendel’s ‘inherited factors’?

Answer 7

Genes