Inheritance, Variation and Evolution

Question 1

Give 3 facts about DNA

Answer 1

1. Determines what inherited characteristics you have
2. Found in the nucleus of animal and plant cells in chromosomes that normally come in pairs
3. It’s a polymer as it’s made up of two strands coiled together like a double helix

Question 2

What is DNA?

Answer 2

The chemical that all the genetic material in a cell is made up from and contains coded information

Question 3

What is a gene?

Answer 3

A small section of DNA found on a chromosome that codes for a particular sequence of amino acids put together for a specific protein

Question 4

Give 3 facts about genes

Answer 4

1. 20 amino acids are used but they make up thousands of different proteins
2. They tell us what order to put the amino acids in
3. Determines what type of proteins the cell produces and what type of cell it is

Question 5

What is a genome?

Answer 5

Entire set of genetic material in an organism

Question 6

Give 3 facts about genomes

Answer 6

1. Allows scientists to identify genes in a genome that a linked to a disease
2. Helps us understand and develop effective treatments
3. Trace migration

Question 7

What is sexual reproduction?

Answer 7

Genetic information from two organisms combine to produce an offspring genetically different to either parent

Question 8

What is asexual reproduction?

Answer 8

By mitosis, one parent produces a new cell with the exact same genetic information

Question 9

What is meiosis?

Answer 9

Produces cells which have half the normal number of chromosomes

Question 10

Give the 4 steps of meiosis

Answer 10

1. Cell duplicates
2. First division
3. Pulled apart - one copy of each chromosome
4. Second division and pull apart

Question 11

What happens after two gametes have fused?

Answer 11

The new cell divides by mitosis many times to produce new cells in an embryo. The embryo develops and the cells start to differentiate into different types of specialised cells that make up an organism.