Evolution + inheritance

Where in the cell is the DNA found?

• Vacuole

• Cytoplasm

• Nucleus

• Chloroplast

Answer explanation

DNA is found inside the nucleus of every single cell in every living organism!

Variation can...

• Only happen in animals

• Be inherited or environmental

• Only be inherited

Answer explanation

Variation is all the differences between living organisms. It can be inherited through DNA, or due to environmental factors, like how much food an animal gets.

Examples of discontinuous variation are...

• Height and length of finger

• Height and eye colour

• Height and hair colour

• Eye colour and hair colour

Answer explanation

Discontinuous variation is variation that fits into one category or another, e.g. eye colour can either be blue or brown or green. Continuous variation is variation that exists along a scale - you can measure it in an amount, e.g height or weight.

What is an allele?

• A copy/ variation of a gene

• The gene you get from your mum

• Two genes

• Dominant

Answer explanation

You inherit two copies of each gene - one from your mother and one from your father. Each one is called an allele.

What does it mean if an allele is dominant?

• You need two copies of it to see it.

• You only need one copy of it to see it.

• It is stronger.

• You got it from your Dad.

Answer explanation

If you have a copy of a dominant allele, it will always show up. E.g. you have one allele for blue eyes which is recessive and one allele for brown eyes which is dominant. You will have brown eyes.

What are chromosomes?

• Part of a cell

• Tightly coiled DNA

• Tightly coiled nucleus

• Tightly coiled protein

Answer explanation

DNA is tightly coiled into chromosomes so that a huge amount of it can fit into our cells and be kept stable and protected.

Which scientists worked on the theory of evolution?

• Darwin and Lamarck

• Watson, Crick and Franklin

Answer explanation

Charles Darwin's theory of how evolution works by natural selection is widely accepted today.

Watson, Crick and Franklin discovered the structure of DNA much much later.

Mutations are...

• Always BAD

• Random changes in the DNA

• Changes to the cell structure

• Always GOOD

Answer explanation

Mutations are random changes in the DNA. They can be good or bad, but most often do nothing at all. Good mutations lead to evolution :)

What is natural selection?

• Where one organism is different and is better adapted to the environment and is able to pass on their genes to their offspring

• Where one organism is stronger than another so it pushes it out of an environment

• A theory developed by Lamarck

• A mutation that leads to a new species

Answer explanation

Natural selection is also known as 'survival of the fittest'. It's not the fastest, strongest organism that always survives, but the one most well adapted to its environment.

How many chromosomes do humans have?

• 115

• 46 pairs

• 23 pairs

• 23

Answer explanation

Humans have 23 pairs of chromosomes (46 altogether). One chromosome from each pair is inherited from the mother and one from the father.