Genetic variation and its control

Question 1

Why do organisms have similar characteristics to parents?

Answer 1

The characteristics are carried by genes, which are passed on in sex cells (gametes) from which the offspring develop.

Question 2

Chromosomes carry what?

Answer 2

The genes that control the characteristics of the body.

Question 3

Chromosomes are found in what part of the cell?

Answer 3

The nucleus.

Question 4

Different genes do what?

Answer 4

Control different characteristics of the body.

Question 5

Differences in characteristics can be due to what type of factors?

Answer 5

Inheritance.
Environmental.
Or a combination of both eg: hair colour.

Question 6

What are the two types of reproduction?

Answer 6

Asexual and sexual.

Question 7

What is asexual reproduction?

Answer 7

Reproduction where there is no fusion of gametes, meaning only one parent is needed and offspring are clones of that parent.

Question 8

What is sexual reproduction?

Answer 8

The fusion of two gametes from two parents (one male gamete and one female gamete).

Question 9

Plants can be produced quickly how?

Answer 9

By taking cuttings from older plants and growing them to make new plants genetically identical to the parent.

Question 10

Modern cloning techniques include:

Answer 10

1) Tissue culture – using small groups of cells from
part of a plant.
2) Embryo transplants – splitting apart cells from a developing animal embryo before they become specialised, then transplanting the identical embryos into host mothers.
3) Adult cell cloning – the nucleus is removed from an unfertilised egg cell. The nucleus from an adult body cell, eg a skin cell, is then inserted into the egg cell. An electric shock then causes the egg cell to begin to divide to form embryo cells. These embryo cells contain the same genetic information as the adult skin cell. When the embryo has developed into a ball of cells,
it is inserted into the womb of an adult female to continue its development.

Question 11

How can genetic engineering work?

Answer 11

Enzymes “cut out” genes from chromosomes and then the gap is filled with the new gene.

Question 12

Concerns about GM crops include…

Answer 12

…the effect on populations of wild flowers and insects, and uncertainty about the effects of eating GM crops on human health.