3.1 Genes

Question 1

What is a gene?

Answer 1

Heritable factor, consists of DNA and influences a specific characteristic

Question 2

What is DNA?

Answer 2

Genetic blueprint, codes and determines characteristics of organisms (physical, behavioural, physiological features)

Question 3

What is a chromosome?

Answer 3

A threadlike structure made of DNA and proteins

Question 4

What is an allele?

Answer 4

Alternative form of a gene that codes for different variations of specific trait; differ from each other by one/few base sequences

Question 5

What is a base substitution mutation?

Answer 5

When a nucleotide in DNA is replaced with another (e.g. U instead of A)

Question 6

What are the 3 point mutations?

Answer 6

When a gene is added, removed or changed.

Beneficial mutations (missense) change gene sequence to create new variations of a trait

Detrimental mutations (nonsense) shortens gene sequence, removing normal function of trait

Neutral mutations (silent) have no effect on functioning of features

Question 7

What is a genome?

Answer 7

The whole of the genetic information of an organism (size order: genetic code -> gene -> genome)

Question 8

What is the HGP?

Answer 8

Human Genome Project, showed that humans share majority of gene sequence

Question 9

What is sickle cell anaemia?

Answer 9

When base substitution mutation occurs in HBB gene, creates sticky/rigid/crescent shaped red blood cells, can block blood flow