B2.3.5 - Inheritance

Question 1

What is the name of the chemical that makes up a persons genetic material?

Answer 1

DNA

Question 2

Describe how genetic material is passed from parents to their children.

Answer 2

Sperm contians 23 chromosomes

Egg contains 23 chromosomes

During fertilisation genetic material joins together.

Each nucleus in the resulting embryo contains 46 chromosomes

Question 3

Another name for an egg cells is an…

Answer 3

ovum

Question 4

What is the scientific name for sex cells (eggs and sperm)?

Answer 4

Gametes

Question 5

How many chromosomes are found in the nucleus of a body cell?

Answer 5

46

(23 pairs)

Question 6

Where is a persons genetic material stored?

Answer 6

In the nucleus of their cells.

Question 7

What is a gene?

Answer 7

A section of DNA…

…that codes for a characteristic e.g. eye colour

Question 8

How many chromosomes are found in a sperm cell?

Answer 8

23

Question 9

Describe the difference between a gene and a chromosome

Answer 9

Gene is a short section of DNA that codes for a characteristic e.g eye colour

Chromosome is a long stand of DNA that contains many genes, which is coiled up to save space.

Question 10

How many chromosomes are found in an egg cell (ovum)?

Answer 10

23

Question 11

Why do we look like both parents?

Answer 11

Because you inherit half of each parents chromosomes.

Therefore you inherit half of each parents genetic material (genes)

Question 12

What is a chromosome?

Answer 12

A coiled up strand of DNA…

…that contains many genes.

Question 13

Explain why communication between scientists was important in the discovery of the structure of DNA.

Answer 13

• The structure of DNA was discovered using work from two laboratories.
• Wilkins and Franklin used X-rays to take images of DNA crystals.
• Watson and Crick saw this image and used it to work out the double helix structure of DNA.
• Evidence from other scientists helped Watson and Crick to prove that DNA had a double helix structure.
• If Watson and Crick had not seen these images it would have taken longer to identify the structure of DNA.
• Scientists communicate evidence by publishing their results, presenting at conferences and meeting each other to discuss their results.
• If scientists don’t communicate or share their findings, different laboratories could be researching the same thing, or people may not have all of the evidence they need to draw a conclusion.

Question 14

What is the function of the nucleus of a cell?

Answer 14

To hold the genetic material of a person (DNA)

To control the cell’s activities.