Inheritance, variation and evolution

Question 1

What does meiosis do?

Answer 1

HALVES the number of CHROMOSOMES and produces GAMETES.

Question 2

Where does meiosis take place?

Answer 2

In REPRODUCTIVE ORGANS (testes and ovaries in animals).

Question 3

Explain the different stages of meiosis. (3)

Answer 3

• All of the chromosomes are COPIED.
• The cell now DIVIDES into TWO.
• Both of these cells divide one more time forming the GAMETES.

Question 4

What is fertilisation?

Answer 4

When GAMETES from a MALE and FEMALE FUSE together during sexual reproduction (full number of chromosomes now).

Question 5

What is asexual reproduction?

Answer 5

Where there is only ONE parent.

Question 6

What are asexual offspring also known as and why?

Answer 6

CLONES, as they are all genetically IDENTICAL.

Question 7

What type of cell division does asexual reproduction involve?

Answer 7

Mitosis.

Question 8

Why does meiosis not take place in asexual reproduction?

Answer 8

Because asexual reproduction does NOT involve GAMETES.

Question 9

How is sexual reproduction in relation to environmental change important?

Answer 9

Sexual reproduction gives a species a GREATER CHANCE OF SURVIVAL if conditions become challenging.

Question 10

Why do offspring produced from sexual reproduction have a greater chance of survival?

Answer 10

As there is GENETIC VARIATION so some of the offspring may survive (best adapted).

Question 11

How have food crops been selectively breed?

Answer 11

To be DISEASE RESISTANT.

Question 12

Describe how you would selectively breed large cows for meet. (4)

Answer 12

• First we take largest male and female cow from a mixed population and BREED them together.
• SEXUAL REPRODUCTION produces VARIATION in the offspring.
• So we select the LARGEST male and female offspring and BREED these together.
• Continue doing this over MANY GENERATIONS until all offspring are large.

Question 13

What big problem is there from selective breeding?

Answer 13

If we breed together CLOSELY RELATED animals or plants, then we get INBREEDING.

Question 14

What can inbreeding cause some breeds to be prone?

Answer 14

DISEASE or inherited defects.

Question 15

What can lead to bacteria becoming resistant to antibiotics?

Answer 15

If we use antibiotics where they are NOT NEEDED (e.g. viral diseases).

Question 16

Describe how bacteria can become resistant to antibiotics. (4)

Answer 16

• A random MUTATION can lead to bacteria becoming RESISTANT to antibiotics.
• The antibiotic KILLS NON-RESISTANT bacteria .
• The resistant bacterium remains and REPRODUCES.
• Now all the bacteria are resistant to the antibiotic.

Question 17

What did Carl Linnaeus develop?

Answer 17

He divided all living organisms into TWO KINGDOMS: animal kingdom and plant kingdom.

Question 18

What did Linnaeus do to each kingdom?

Answer 18

Divided them into a number of smaller categories.

Question 19

What are all the categories Linnaeus developed called?

Answer 19

Kingdom..King
Phylum....Philip
Class.......Came
Order.......Over
Family.......For 
Genus....Good
Species..Soup

Question 20

What is every organism named from?

Answer 20

Their GENUS and their SPECIES (known as BINOMIAL SYSTEM).

Question 21

What was developed by Carl Woese?

Answer 21

The three domain system.

Question 22

What is in the three domain system?

Answer 22

• ARCHAE (primitive bacteria).
• TRUE BACTERIA (kind that live in human digestive system).
• EUKARYOTA (animals, plants and fungi).