Inheritance Variation and Evolution

Question 1

What is an allele?

Answer 1

An alternative form of a gene.

Question 2

What is meant by asexual reproduction?

Answer 2

The production of offspring from a single parent by mitosis. The offspring are clones of the parent.

Question 3

What is a chromosome?

Answer 3

Structures that contain the DNA of an organism and are found in the nucleus.

Question 4

What is cystic fibrosis?

Answer 4

A disorder of cell membranes that is caused by a recessive allele.W

Question 5

What is DNA?

Answer 5

a polymer that is made up of two strands that form a double helix.

Question 6

What is meant by a dominant allele?

Answer 6

An allele that is always expressed, even if only one copy is present.

Question 7

What is ‘fertilisation’?

Answer 7

The fusion of male and female gametes.

Question 8

What is a gamete?

Answer 8

The sex cells of an organism.

Question 9

What are the animal gametes?

Answer 9

Sperm cell and egg cell

Question 10

What are the plant gametes?

Answer 10

Pollen and egg in plants

Question 11

What are genes?

Answer 11

A section of DNA that codes for a protein which determines your characteristics.

Question 12

What is meant by heterozygous?

Answer 12

A genotype that has two different alleles, one dominant and one recessive.

Question 13

What is meant by homozygous?

Answer 13

A genotype that has two of the same alleles.

Question 14

What is meiosis?

Answer 14

The two-stage process of cell division that reduces the chromosome number of the daughter cells.

Question 15

What is a phenotype?

Answer 15

The characteristic expressed because of the combination of alleles.

Question 16

What is a recessive allele?

Answer 16

An allele that is only expressed if two copies of it are present.

Question 17

What is the first stage of meiosis?

Answer 17

Before meiosis occurs, each chromosome is copied exactly, the two copies stay attached to one another.

Question 18

What is the second stage of meiosis?

Answer 18

Each chromosome finds its partner from the other set.

Question 19

What is the third stage of meiosis?

Answer 19

The chromosomes separate from their partners and the cell divides

Question 20

What is the fourth stage of meiosis?

Answer 20

The cell divides once more separating the two copies of each chromosomes

Question 21

What is the fifth stage of meiosis?

Answer 21

four new daughter cells are produced with each having a single set of chromosomes (23 in humans)

Question 22

What does meiosis produce?

Answer 22

Gametes for sexual reproduction.

Question 23

How many cells does mitosis produce?

Answer 23

Two daughter cells

Question 24

How many times do the cells divide in mitosis?

Answer 24

Once.

Question 25

How many chromosomes are in each daughter cells?

Answer 25

46.

Question 26

What is the use of mitosis?

Answer 26

growth and repair and asexual reproduction

Question 27

What are the female chromosomes?

Answer 27

XX

Question 28

What are the male chromosomes?

Answer 28

XY

Question 29

Why is there variation?

Answer 29

The genes that have been inherited The conditions in which they have developed A combination of genes and environment,

Question 30

What is evolution?

Answer 30

The theory that all living things have evolved from a simple life form by natural selection.

Question 31

How do you perform selective breeding?

Answer 31

1, Choose parents who have the desired characteristics 2. Select the best offspring and breed these to make the next generation 3. The offsprings are bread over and over again until the desired result is achieved.

Question 32

What is genetic engineering?

Answer 32

The process by which scientists manipulate and change the genotype of an organism.