Inheritence

Question 1

What is DNA

Answer 1

A massively long structure which super coils itself around proteins in the body in order to form chromosomes. These are ‘X-like’ structures which tidy up the nucleus.

Question 2

Why do the DNA latch onto proteins in the body?

Answer 2

Because they are readily available

Question 3

What is the purpose of super coiling.

Answer 3

It tidied up he nucleus due to tight coiling and allows everything to fit

Question 4

Where are genes found?

Answer 4

On the chromosomes

Genes are bands on chromosomes

Question 5

Female gene formation

Answer 5

XX

Question 6

Male gene formation

Answer 6

XY

Question 7

What determines whether the child will be a boy or a girl?

Answer 7

The sperm

Question 8

Describe how genes, chromosomes and DNA are all linked

Answer 8

The DNA form chromosomes, which contain small structures called genes on them.

Question 9

Where are chromosomes found

Answer 9

In the nucleus

Question 10

How many chromosomes are there in most human cells

Answer 10

46

Question 11

How many pairs of non sex chromosomes are there and what are their names

Answer 11

Autosomes

22 pairs

Question 12

How many pairs of sex chromosomes are there?

Answer 12

One, labelled X and Y

Question 13

A=

Answer 13

T

Question 14

C=

Answer 14

G

Question 15

On the structure of DNA, what does the s stand for

Answer 15

Sugar

Question 16

On the structure of DNA, what does the p stand for

Answer 16

Phosphate

Question 17

On the structure of DNA, what is G bonded with C labelled as

Answer 17

Nitrogenous bases

Question 18

What is a base, bonded with sugar and phosphate labelled as?

Answer 18

A nucleotide

Question 19

What is mitosis

Answer 19

A form of cell division that produces two identical diploid daughter cells from a diploid body cell, used for growth and repair in the body and in asexual reproduction. It occurs in all body cells apart from gametes.

Question 20

What are the stages of mitosis

Answer 20

Interphase 
Prophase 
Metaphase 
Anaphase 
Telophase 

(PMAT)

Question 21

Mitosis chromosomes

Answer 21

Starts off with 46

Goes through DNA replication and has 92

Then separates into daughter cells which each have 46

Question 22

Interphase

Answer 22

Before mitosis occurs

90 % of the cycle
DNA replication occurs in it (46-92)
This is because you have to duplicate the genetic material in the cell before splitting, or else they would not have the correct number of chromosomes.

Question 23

Prophase

Answer 23

Nuclear envelope disintegrates
DNA supercoil to form chromosomes
The chromosomes take an X structure

Question 24

Metaphase

Answer 24

Chromosomes attach to the equator of the cell ‘line up’

Question 25

Anaphase

Answer 25

Spindle fibers drag chromosomes to the piles of the cell.

Chromosomes are pulled to the ends of the cell

Question 26

Telophase

Answer 26

The nucleur envelope reforms around the chromosomes, which then unwind.

The cell divides (cytokinesis)

Two diploid daughter cells form, each containing 46 chromosomes

Question 27

What is the purpose of mitosis?

Answer 27

• growth
• asexual reproduction
• repair of the tissue
• cloning

Question 28

What cells would meiosis make?

Answer 28

Gametes

Question 29

What happens in meiosis?

Answer 29

You have to go through PMAT twice in meiosis because otherwise when the sperm and the egg got together in reproduction, there would be too many chromosomes and they wouldn’t function.

Question 30

Meoisis chromosomes

Answer 30

46 
92 - DNA replication
PMAT
46     46
PMAT
23 23 23 23 haploid daughter cells

Question 31

Haploid

Answer 31

Half the genetic number of chromosomes

Question 32

Diploid

Answer 32

Normal amount of chromosomes

Question 33

Why is it important that humans endure meiosis?

Answer 33

Because variation is needed so meoisis creates non- identical daughter cells and sexual reproduction also creates variety

Question 34

What is an allele?

Answer 34

Different versions of the same gene
Different characteristics
E.g. hair colour gene.

Question 35

Phenotype

Answer 35

The visible physical appearance of an organism based on the expression of genes

Question 36

Heterozygous

Answer 36

The alleles in the organisms are different

Question 37

Homozygous

Answer 37

Both alleles in the organism are identical

Question 38

Recessive

Answer 38

And allele which is only expressed when it is with another identical allele.

Question 39

Dominat

Answer 39

And allele that is always expressed even when it is paired with another allele

Question 40

Genotype

Answer 40

The genetic composition of an organism

Question 41

A gene is

Answer 41

A section of molecule of DNA and a gene codes for a protein

Question 42

DNA molecule

Answer 42

Two strands coiled to form a double helix, linked by a 4 nitrogenous bases AT CG

Question 43

What are alleles

Answer 43

Alternative forms of genes which give rise to differences in inherited characteristics

Question 44

Why do cells need to divide

Answer 44

To replace worn out cells form growth and to replace dead cells

Question 45

List 3 places in ur body where mitosis occurs

Answer 45

Skin, blood, bone marrow

Question 46

When a genetic material of a cell changes it is called

Answer 46

Mutation

Question 47

Describe the relationship between genes and the characteristics of an organism

Answer 47

Each gene codes for a specific protein, the proteins will determine the phenotype

Question 48

Advantages of reproducing sexually

Answer 48

Varied species
2 parents to raise offspring
More chance of survival
Prevents monoculture

Question 49

Why self-pollinate?

Answer 49

To stop cross pollination

To control the gene pool or prevent other genes getting in

Question 50

Environmental factor that may increase the probability of a random gene mutation

Answer 50

UV, x ray, tar from cigarettes