Inheritance, Variation and Evolution

Question 1

What does DNA stand for?

Answer 1

DNA stands for deoxyribonucleic acid

Question 2

What is DNA?

Answer 2

The chemical a cell’s genetic material is made from

Question 3

What is the structure of DNA called?

Answer 3

The structure of DNA is a double helix

Question 4

What is a chromosome?

Answer 4

A chromosome is a long molecule of DNA that normally come in pairs

Question 5

How many pairs of chromosomes do humans have?

Answer 5

Humans have 23 pairs of chromosomes

Question 6

What is the male chromosome?

Answer 6

The male chromosome is XY

Question 7

What is the female chromosome?

Answer 7

The female chromosome is XX

Question 8

What is a gene?

Answer 8

A gene is a small section of DNA found in a chromsome

Question 9

What does a gene code for?

Answer 9

A gene codes for a specific sequence of amino acids

Question 10

What is a genome?

Answer 10

A genome is an entire set of genetic information

Question 11

What do genomes help us better understand?

Answer 11

Genomes help us better understand inherited disorders and the migration patterns of past populations

Question 12

What are the things that make up a nucleotide?

Answer 12

The phosphate, sugar-phosphate backbone, sugar and base up a nucleotide

Question 13

What are the base pairs?

Answer 13

A + T / C + G

Question 14

What is the first stage of protein synthesis?

Answer 14

The first stage of protein synthesis is transcription, which is where the bases of genes are copied into an mRNA strand. The mRNA strand then passes out of the nucleus into the cytoplasm

Question 15

What is the second stage of protein synthesis?

Answer 15

The second stage of protein synthesis is translation. The mRNA attaches to the ribosome. Amino acids are brought to the ribosome on carrier molecules (RNA). The ribosomes read the bases on the mRNA to join the correct amino acids in the correct order.

Question 16

What are four characteristics which could be selected for the breeding of animals and plants?

Answer 16

• Disease resistance in crop plants
• Animals that produce more meat or milk
• Domestic dogs with a gentle nature
• Large or unusual flowers

Question 17

What is a major disadvantage caused by selective breeding?

Answer 17

A large disadvantage caused by selective breeding is that it can lead to interbreeding where some breeds are particularly prone to disease or inherited defects

Question 18

How often do mutations occur?

Answer 18

Mutations occur continuously

Question 19

How likely is it that a mutation will lead to a new phenotype?

Answer 19

It is very rare that a mutation will lead to a new phenotype

Question 20

What is a phenotype?

Answer 20

A phenotype is an individual’s observable traits, such as height, eye colour, and blood type

Question 21

What is a genotype?

Answer 21

The genotype is the collection of alleles that determine an organism’s characteristics

Question 22

What are examples of GM organisms?

Answer 22

Examples of GM organisms include;

• Insulin-producing bacteria (human insulin gene injected from bacterial cells to produce insulin for diabetes)
• Crops that can kill pests, resist herbicides and have increased shelf life
• Sheep that can produce drugs in their milk

Question 23

What is the process of insulin being made from bacteria?

Answer 23

The process of insulin being made from bacteria include;

1) . remove the desired gene with a restriction enzyme
2) . cut plasmid open with restriction enzyme
3) . ligase enzyme inserts a gene into the plasmid
4) . plasmid put back in bacteria
5) . bacteria cultured in the fermentor
6) . lots of insulin is produced

Question 24

What are the pros of genetic engineering?

Answer 24

The pros of genetic engineering are that it produces lots of cheap food, less waste due to pests, more money for farmers and extra nutrients in food

Question 25

What are the cons of genetic engineering?

Answer 25

The cons of genetic engineering is that it results in reduced biodiversity (monoculture), possible production of superbugs, possible human harm

Question 26

What can genetic engineering lead to?

Answer 26

Genetic engineering can lead to gene therapy (where workable genes are inserted) and plants that grow on mars

Question 27

What is natural selection?

Answer 27

Natural selection is the theory that all species have evolved from simple life forms that first developed more than 3 billion years ago

Question 28

What is a clone?

Answer 28

A clone is a complete genetic copy of an organism

Question 29

What are some examples of cloning in plants?

Answer 29

Cloning in the plants can come in the forms of:
Cuttings - cuttings from healthy plants that can be treated in auxin to stimulate growth
Tissue culture - cells put into growth medium treated with hormones and grown into seedlings then planted

Question 30

What are some examples of cloning in animals?

Answer 30

Cloning in animals can come in the form of:
Embryo transplant - separating cut embryos into individual cells and allowing them to grow
Adult cell cloning - take a cell and transform an egg