2.7

Question 1

What is genetic material called?

Answer 1

DNA

Question 2

What structure has DNA got?

Answer 2

Double helix

Question 3

What is found on the DNA?

Answer 3

Genes.

Question 4

What is a gene? What does it control?

Answer 4

Small section of DNA

Controls your features

Question 5

What does a gene do ?

Answer 5

Encodes the amino acids in protein

Question 6

What is chromosome?

Answer 6

Short section of DNA

Question 7

What do chromosomes contain?

Answer 7

Genes

Question 8

How many pairs of chromosomes do human cells have?

Answer 8

23

Question 9

How many copies of each gene do we have ?

Answer 9

2

Question 10

What is an allele?

Answer 10

Different versions of the same gene

Question 11

Where are chromosomes found in the human cells?

Answer 11

Nucleus

Question 12

What happens during the first stage of mitosis?

Answer 12

Cells are copied

Question 13

What happens in the second stage of mitosis?

Answer 13

Cells are split into 2 identical cells

Question 14

When does mitosis happen?

Answer 14

During growth
Repairing cells
Asexual reproduction

Question 15

What are gametes? Where are they found?

Answer 15

Sex cells

Sperm cells (testes)
Egg cell (ovaries)

Question 16

How many chromosomes are in gametes?

Answer 16

23 single chromosomes

Question 17

What is the first step of meiosis?

Answer 17

Chromosomes are copied

Question 18

What happens in the second stage of meiosis?

Answer 18

The cell splits into two

Question 19

What happens in the third stage of meiosis?

Answer 19

The split cells split again

Question 20

How many cells are produced during meiosis?

Answer 20

4

Question 21

How many cells are produced in mitosis?

Answer 21

2

Question 22

What are the newly formed cells made by mitosis like, in terms of their parents?

Answer 22

Genetically identical

Question 23

Describe the prices of mitosis.

Answer 23

Parent cell
Chromosomes make identical copies
Line up song centre
Spindle fibres separate them
Two daughter cells form - identical

Question 24

What are the stages of meiosis?

Answer 24

Parent cell
Chromosomes copy
Similar chromosomes pair up
DNA gets swapped
Chromosomes divide
Chromosomes divide again

Question 25

What is the process of fertilisation?

Answer 25

Fusion of male and female gametes New cell divides constantly by mitosis Creates many cells Creates baby

Question 26

How are gametes made?

Answer 26

Meiosis

Question 27

What is a stem cell?

Answer 27

Cells that can change into any type of cell Stem cells are undifferentiated but can differentiate into any specialised cell

Question 28

Where can we find stem cells?

Answer 28

Embryos | Bone marrow

Question 29

What does differentiation mean?

Answer 29

Cells specialise

Question 30

What can stem cells be used to treat?

Answer 30

Disease such as paralysis

Question 31

What are the ethical issues of stem cells?

Answer 31

Embryonic- killing human embryo

Question 32

Why does asexual production lead to offspring having same alleles as its parent?

Answer 32

Same/ identical cells as only one parent

Question 33

How are your chromosome pairs made up? Of what?

Answer 33

1 from mother | 1 from father

Question 34

How many copies of each gene do we have ?

Answer 34

2

Question 35

How are dominant alleles shown?

Answer 35

Capital letter

Question 36

How are recessive alleles shown?

Answer 36

Lowercase letter

Question 37

What's the difference between dominant and recessive alleles?

Answer 37

Dominant control features when there is one allele Recessive controls if they are both recessive alleles

Question 38

What does genotype mean?

Answer 38

The alleles present

Question 39

What is meant by phenotype?

Answer 39

The features that alleles produce

Question 40

What does homozygous mean?

Answer 40

Both alleles are the same

Question 41

What does heterozygous mean?

Answer 41

Alleles are different

Question 42

How does DNA fingerprinting identify people?

Answer 42

Everyone's DNA is different (unique)

Question 43

How do people get genetic disorders?

Answer 43

Inherited from parents

Question 44

How are genetic disorders caused?

Answer 44

Faulty alleles

Question 45

What is meant genetic disorders being carried?

Answer 45

Recessive alleles carry the disorder

Question 46

What is polydactyly? How is it caused?

Answer 46

Inherited extra fingers or toes caused by dominant alleles

Question 47

Why can polydactyly not be carried?

Answer 47

It's a dominant allele

Question 48

What does cystic fibrosis (CF) cause?

Answer 48

Defective cell membrane | Lung damage

Question 49

How is CF caused?

Answer 49

Recessive allele -carried

Question 50

How are some people the carrier of CF but don't have the disorder?

Answer 50

If the parents each have a heterozygous allele pair then The child will only be a carrier cause they don't have 2 recessive alleles

Question 51

How is embryo screening (or PIGD) carried out?

Answer 51

Sperm and egg mixed -fertilised Fertilised egg develop into embryo (8 cells) One cell is removed and analysed for CF allele Health embryo planted into uterus

Question 52

What is an alternative to embryo screening?

Answer 52

Placenta taken from pregnant woman | If defective allele found it is aborted

Question 53

What are the pros of embryo screening ?

Answer 53

No abortion needed | Less miscarriage

Question 54

What are the cons of embryo screening?

Answer 54

Expensive Healthy left over embryos destroyed Against religious belief