B1.7 Genetic Variation and Its Control

Question 0

What is DNA?

Answer 0

DNA is the chemical that forms the chromosomes.

Question 1

In which part of a cell is the genetic information found?

Answer 1

Nucleus.

Question 2

Describe the structure of DNA.

Answer 2

DNA is a long molecule made up of two strands that are twisted together to make a spiral. This is known as double helix.

Question 3

How many chromosomes is present in human body cells?

Answer 3

46 chromosomes or 23 pairs.

Question 4

How many chromosomes is present in human sex cells?

Answer 4

23 chromosomes.

Question 5

Name the characteristics that are genetically controlled.

Answer 5

• attached or detached earlobes
• thumb straight or curved
• dimples
• eye colour
• shape of nose

Question 6

What is a gene?

Answer 6

Genes are a section of the DNA. They control the different proteins and enzymes made in our body.

Question 7

What is asexual reproduction?

Answer 7

Asexual reproduction produces offspring that are genetically identical to the parent.

Question 8

What is sexual reproduction?

Answer 8

Sexual reproduction involves fertilisation of the gametes to form a new individual.

Question 9

What is fertilisation?

Answer 9

The fusion of the male and female gamete during sexual reproduction.

Question 10

Name the three modern cloning techniques.

Answer 10

• tissue culture
• embryo transplants
• adult cell cloning

Question 11

What is a clone?

Answer 11

A clone is an individual that has been produced asexually and is genetically identical to the parent.

Question 12

How is gene cut out of one organism?

Answer 12

Using enzymes.