B1 - You and Your Genes

Question 1

Phenotype

Answer 1

The characteristics which show up in our appearance

Question 2

What environmental factors affect our characteristics?

Answer 2

• Climate
• Diet
• Physical accidents
• Culture
• Lifestyle

Question 3

2 examples of characteristics controlled by genes:

Answer 3

• Dimples

- Height

Question 4

Genome

Answer 4

The complete gene set of an organism

Question 5

Put these in order of decreasing size: Gene, Chromosome, DNA, Nucleus

Answer 5

Nucleus -> Chromosome -> DNA -> Gene

Question 6

What do genes do?

Answer 6

Carry the instructions that control how you develop and function. They tell cells which protein to make.

Question 7

What is DNA make of?

Answer 7

4 chemicals called bases

Question 8

The order of bases determines…

Answer 8

The order of amino acids in a protein

Question 9

What are the two types of protein?

Answer 9

Functional and Structural

Question 10

What do functional proteins do? Give 3 examples of said proteins

Answer 10

Enable the body to function: enzymes, antibodies and hormones

Question 11

What do structural proteins do? Give 2 examples of said proteins

Answer 11

Give the body structure, rigidity and strength e.g collagen in ligaments and keratin in skin

Question 12

What has the human genome project done?

Answer 12

Identified the location of all the genes on human chromosomes

Question 13

How many chromosomes do human cell have?

Answer 13

23 pairs of 46 in total

Question 14

How many chromosomes do sex cells have?

Answer 14

23

Question 15

What are Alleles?

Answer 15

The different a forms in which genes controlling a characteristic can occur

Question 16

Homozygous

Answer 16

When someone has two alleles of a gene which are identical

Question 17

Heterozygous

Answer 17

When someone has two alleles for a gene which are different

Question 18

Two types of allele

Answer 18

Dominant and Recessive

Question 19

Punnet Squares are used to…

Answer 19

Show genetic crosses and find the probability of two parents producing different types of offspring

Question 20

A family tree diagram is used to…

Answer 20

Show the inheritance of a trait in a family over several generations and trace a genetic disorder over generations

Question 21

XX chromosomes are found in

Answer 21

Females

Question 22

XY chromosomes are found in

Answer 22

Males

Question 23

Genetic screening

Answer 23

A process used to check for a particular disease

Question 24

Clones

Answer 24

Individuals with identical genes

Question 25

3 examples of organisms which reproduce asexually

Answer 25

Bacteria, Some plants and Simple animals (e.g. Hydra)

Question 26

Two ways plants can reproduce asexually & examples of plants which use each method

Answer 26

• By Using Runners (e.g. Strawberries) shoots sent out to grow into identical plants
• By Producing bulbs (e.g. Daffodils)

Question 27

Advantages of cloning

Answer 27

• Successful characteristics are seen in offspring

- Asexual reproduction is useful where plants and animals live in isolation

Question 28

Disadvantages of cloning

Answer 28

• There is no genetic variation

- If conditions change or a disease arises the population could be wiped out

Question 29

2 animals which reproduce asexually

Answer 29

Starfish and Sea anemones

Question 30

What are the two types of stem cell?

Answer 30

Adult and Embryonic

Question 31

Adult stem cells

Answer 31

Are unspecialised cells which can develop into many (but not all) cell types

Question 32

Embryonic stem cells

Answer 32

Unspecialised cells that can develop into any type of cell

Question 33

Differentiation

Answer 33

When cells become specialised after the 8 cell stage

Question 34

Why is the use of embryonic stem cells controversial?

Answer 34

-They are usually taken from unused embryos following fertility treatment and their use involves the destruction of the embryo

Question 35

Stem cells could be used for:

Answer 35

• The testing of new drugs
• Understanding how cells become specialised in the early stages of human development but the switching on and off of genes
• Renewing damaged cells in spinal injuries, heart disease, Huntington’s and Parkinson’s

Question 36

What are the 3 different types of cloning?

Answer 36

• Therapeutic cloning
• Embryo transplants
• Fusion cell cloning

Question 37

Steps of therapeutic cloning:

Answer 37

1. Nucleus taken out of a human egg cell
2. Nucleus from a patient’s cell put into the egg cell
3. Egg cell stimulated to develop into an embryo
4. Stem cells taken from embryo
5. Stem cells grown in a container of warm nutrients
6. Stem cells treated to develop into required cell types

Question 38

How are embryo transplants performed?

Answer 38

1. A developing embryo is removed from a pregnant animal at an early stage before its cells have had time to differentiate.
2. The cells are separated, grown for a whole in a laboratory the transplanted into host mothers.
3. When the offspring are born they are not identical to their host mother but to each other and the original pregnant animal.

Question 39

Steps of fusion cell cloning

Answer 39

1. The nucleus from a body cell is extracted and inserted into an egg cell that has had its nucleus removed.
2. This gives the egg cell a full set of genes without being fertilised.
3. The embryo is implanted into a suitable surrogate mother.

Question 40

Who is Dolly the Sheep?

Answer 40

The first mammal to be cloned using adult cell cloning. She was born in the Uk in 1996 and died in 2003.

Question 41

Genotype

Answer 41

Our genetic makeup