Inheritance, Variation and Evolution

Question 1

What does DNA stand for?

Answer 1

Deoxyribonucleic acid

Question 2

What is DNA?

Answer 2

A double stranded polymer that forms a double helix. It contains genetic material.

Question 3

What is a gene?

Answer 3

A gene is a small section if DNA found in a chromosome

Question 4

Where is DNA found?

Answer 4

In chromosomes

Question 5

What is a genome?

Answer 5

A genome is the entire set of genetic material in an organism.
Scientists have worked out the human genome.

Question 6

What are three benefits for understanding the human genome?

Answer 6

1. It allows scientists to identify genes that are linked to disease
2. Allow scientists to develop and understand drugs that effect genetic diseases
3. The genome can be used to trace migration patterns of certain population as when people migrate they develop small changes and adaptations within their genome.

Question 7

What are the four possible bases in DNA?

Answer 7

A,T,C,G

Question 8

Which bases are complimentary to each other?

Answer 8

A and T
C and G

Question 9

What structure is DNA?

Answer 9

Double Helix Structure

Question 10

Where does protein synthesis take place?

Answer 10

Ribosomes

Question 11

How are proteins made?

Answer 11

Proteins are made from amino acids. They are made of amino acids.

Question 12

What are three uses of proteins?

Answer 12

Enzymes - biological catalysts that speed up reactions
Hormones - used to carry messages around the body
Structural proteins - physically strong

Question 13

What is a mutation?

Answer 13

A mutation is the change in the sequence if DNA resulting in a genetic variant. Mutations happen continuously

Question 14

What can a mutation lead to?

Answer 14

Mutations don’t often cause major changes only small changes in appearance however they can lead to changes in the amino acid and sometimes changes in the protein?

Question 15

What do X and Y chromosomes decide?

Answer 15

Your sex

Question 16

How many pairs of chromosomes does a human have?

Answer 16

23

Question 17

What chromosomes makes a male and female?

Answer 17

Male - XY
Female - XX

Question 18

What is an allele?

Answer 18

An allele is a different variation of the same gene

Question 19

What does homozygous mean?

Answer 19

A gene is homozygous when it gas two alleles that are the same. A gene can be homozygous dominant or recessive

Question 19

What is a recessive allele?

Answer 19

A allele that controls the development of a characteristic but only when two are present because it can be overruled by the dominant allele.

Question 20

What is a dominant allele?

Answer 20

An allele that controls the development of a characteristic even when only one is present

Question 20

How many alleles do you have per gene in your body?

Answer 20

Two - one on each chromosome pair

Question 21

What does heterozygous mean?

Answer 21

A gene is heterozygous when it’s alleles are different

Question 22

What does genotype mean?

Answer 22

Your genotype is the combination of alleles in a gene. This is written in letters e.g Aa or AA

Question 23

What does phenotype mean?

Answer 23

Phenotype is the characteristic that appears from the genotype.

Question 24

What is cystic Fibrosis ?

Answer 24

Cystic Fibrosis effects cell membranes and results in the body producing thick sticky mucus in the lungs and pancreas.

Question 25

What causes Cystic Fibrosis?

Answer 25

Cystic fibrosis is a recessive disease and is caused by two recessive alleles. Because it is recessive people with one copy will not be effected - they are known as carriers.

Question 26

What is polydactyls?

Answer 26

Polydactyly is a genetic disorder that cause a baby to be born with extra fingers or toes.

Question 27

What causes polydactyly?

Answer 27

A genetic disease caused by a dominant allele so it can be inherited by just one parent.

Question 28

How can embryos be screened for genetic disorders?

Answer 28

During IVF embryos are fertilised in a lab.
Before implantation a cell can be removed from the embryo and can be analysed genetic disorders.