B1.7 Genetic variation and its control

Question 1

What is variation within a species?

Answer 1

Differences in characteristics in organisms in the same species

Question 2

What can differences in characteristics be due to?

Answer 2

The genes they have inherited (genetic causes), the conditions in which they have developed (environmental causes)

Question 3

What does the nucleus of a cell contain?

Answer 3

Chromosomes

Question 4

What do chromosomes carry?

Answer 4

Genes

Question 5

What do genes control?

Answer 5

The characteristics of the body

Question 6

What do different genes control?

Answer 6

The development of different characteristics of an organism

Question 7

Why do plants and animals have similar characteristics to their parents?

Answer 7

Characteristics are determined by genes inherited from their parents

Question 8

What does the combination of genes from both parent cause?

Answer 8

Genetic variation

Question 9

What is environmental variation?

Answer 9

Any difference that has been causes by the conditions something lives in

Question 10

What are some example of a mixture of genetic and environmental variation?

Answer 10

Body weight, height, skin colour, condition of teeth, academic or athletic prowess

Question 11

How many chromosomes does the nucleus contain?

Answer 11

23 pairs

Question 12

What does DNA from?

Answer 12

Chromosomes

Question 13

What is the name of different forms of the same gene?

Answer 13

Alleles

Question 14

What are the two types of reproduction?

Answer 14

Sexual and Asexual

Question 15

What does sexual reproduction involve?

Answer 15

Two parents

Question 16

How many chromosomes does a gamete contain?

Answer 16

23 (half the number of a normal cell)

Question 17

What is sexual reproduction?

Answer 17

The joining (fusion) of male and female gametes

Question 18

What does sexual production lead to?

Answer 18

The mixture of genetic information from two parents resulting in variety in the offspring

Question 19

How many parents are there in asexual reproduction?

Answer 19

One

Question 20

Is there any mixing of genetic information in asexual reproduction?

Answer 20

No

Question 21

What are the individuals produced by asexual reproduction?

Answer 21

Genetically identical to the parent (clones)

Question 22

What are the two ways of cloning plants?

Answer 22

Plant cuttings and tissue culture

Question 23

How can plants be produced quickly and cheaply?

Answer 23

Taking cuttings

Question 24

What do gardeners take cuttings from?

Answer 24

Good plants so that the plants produced will be genetically identical to a good plant

Question 25

What is tissue culture?

Answer 25

Where a few plant cells are put into a growth medium with hormones and they grow into new plants, clones of the parent plant

Question 26

How can tissue culture be made?

Answer 26

Very quickly in very little space and grown all year

Question 27

What are embryo transplants?

Answer 27

The production of cloned offspring using embryo transplants

Question 28

What are the processes of embryo transplants?

Answer 28

Sperm cells are taken from the desired male and egg cells from the desired female. The two are then fertilised. The embryo that develops is then split many times (to form clones) before any cells become developed. These embryos can then be implanted into lots of other cows, each developing into genetically identical organisms

Question 29

What does adult cell cloning involve?

Answer 29

The taking of an unfertilised egg cell and removing of its genetic material. A complete set of chromosomes from an adult body cell is then inserted into the empty egg cell. The egg cell is then stimulated by an electric shock, this makes it divide. When the embryo is a ball of cells its implanted into a adult female to grow a genetically identical copy

Question 30

In genetic engineering, how can genes from the chromosomes of humans and other organisms be removed?

Answer 30

They can be ‘cut out’ by enzymes

Question 31

What is an issue with cloning?

Answer 31

It results in a reduced gene pool

Question 32

What is the problem with a reduced gene pool?

Answer 32

If the population are closely related and a new disease appears, they could all be wiped out as none of the population will have resistance to the disease

Question 33

What do some believe the cloning of animals will result in?

Answer 33

The cloning of humans

Question 34

When do scientists use the method of using enzymes to cut out useful genes?

Answer 34

The insertion of the insulin gene

Question 35

Where else can useful genes be transferred to?

Answer 35

Animals and plants

Question 36

When are useful genes transferred to animals and plants?

Answer 36

At the very early stages of development

Question 37

Why do GM crops have their genes modified?

Answer 37

To make them resistant to viruses, insects and herbicides

Question 38

What are the name of crops which have been modified?

Answer 38

Genetically Modified Crops

Question 39

What is an example of a GM crop?

Answer 39

Crops which are resistant to insect attack or herbicides

Question 40

What do GM crops generally show?

Answer 40

Increased yields

Question 41

What are people concerned the GM crops will effect?

Answer 41

The population of wildflowers and insects and human health

Question 42

What do some people think will happen due to changes in the numbers of weeds and flowers as a result of GM crops?

Answer 42

Decrease in farmland biodiversity

Question 43

Why do some think GM crops are not safe?

Answer 43

They are worried people will develop allergies to the food

Question 44

What do some people think will happen as a result of potential herbicide resistance?

Answer 44

A new ‘superweed’ variety