Inheritance

Question 0

What is the chemical which makes up your genes?

Answer 0

DNA

Deoxyribose nuclic Acid

Question 1

What is genetics?

Answer 1

Study of your genes and how you inherit them from your parents

Question 2

What are small sections of DNA called?

Answer 2

Genes, which are then made up into chromosomes

Question 3

How many chromosomes are in the average human body?

Answer 3

46 chromosomes and 23 pairs.

Question 4

Using knowledge of genetics, what does it enable us to do?

Answer 4

Predict what type if OFFSPRING the parent may produce

Question 5

What are the two forms of gene and explain them?

Answer 5

Dominant; you only need one copy for you to see the characteristic in the person.
Recessive; you need 2 copies for youth see that characteristic.

Question 6

What division divides chromosomes to get gametes?

Answer 6

Meiosis

Question 7

What is a phenotype?

Answer 7

The characteristic that you see

Question 8

What does Heterozygous mean?

Answer 8

When the genes are dominant

e.g. Bb or BB

Question 9

What does Homozygous mean?

Answer 9

Genes are recessive

e.g. bb

Question 10

What does the nucleus contain?

Answer 10

Genetic material in the firm of chromosomes

Question 11

What does a DNA molecule look like?

Answer 11

Two strands coiled together in the shape of a double helix (two spirals)

Question 12

What is Asexual reproduction in humans?

Answer 12

• one parent involved
• offspring have identical genes to the parent
• no variation between patent and offspring

Question 13

What is Mitosis?

Answer 13

“Mitosis is when a cell reproduces itself by splitting, to form two cells with identical sets of chromosomes”

Question 14

What are the 5 steps of mitosis?

Answer 14

1. ) signal to divide, cell duplicates it’s DNA (one copy for each new cell) X-shaped chromosomes formed.
2. ) chromosomes line up at centre of cell and fibres pull them apart. Each go to opposite end of the cell.
3. ) membranes form around each chromosome. These become the nuclei of the new cells
4. ) cytoplasm divides
5. ) two new cells, sane DNA, genetically identical.

Question 15

What does meiosis involve?

Answer 15

4 non identical haploid cells.

Question 16

What is sexual reproduction (in terms of cells) ?

Answer 16

Genetic information from two organisms (mum and dad) is combines to produce offspring which are GENETICALLY DIFFERENT.

Question 17

What are the two gametes in sexual reproduction and who makes them?

Answer 17

• mum and dad

- egg cells and Soren cells

Question 18

how many chromosomes does each gamete contain?

Answer 18

23 chromosomes

So the haploid number is 23.

Question 19

What is fertilisation?

Answer 19

Make gamete fuses with a female gamete to form a zygote (fertilised egg) the zygote ends up with the full set of chromosomes.

Question 20

What happens after the zygote undergoes cell division?

Answer 20

It develops into an Embryo.

Question 21

How is genetic variation random?

Answer 21

The fertilisation of gametes is random.

Question 22

What are the four steps in the first division of MEIOSIS?

Answer 22

1. ) cell duplicates it’s DNA (1 arm of each chromosome is an exact copy of the other arm
2. ) chromosomes line up in pairs in the centre of the cell
3. ) the pairs then get pulled apart and each cell gets one copy of each chromosome.
4. ) each new cell gets a mixture of mum and dad’s genes.

Question 23

What are the two steps in decision 2 of meiosis?

Answer 23

5.) Again the chromosomes line up in the centre of the cell.
Arms of the chromosomes are pulled apart.
6.) 4 haploid gametes are produced each with a single set of chromosomes and genetically different