reproduction and genetics

Question 1

Name the male gamete in plants and animals

Answer 1

In plants: Pollen (sperm cells inside)
In animals: Sperm

Question 2

name the female gamete in plants and animal

Answer 2

both = egg

Question 3

which type of cell division is involved in the production of gametes?

Answer 3

Meiosis

Question 4

Name the type of cell division used in asexual reproduction.

Answer 4

mitosis

Question 5

Explain how fertilised egg cell has the correct calls has the correct number of chromosomes.

Answer 5

Mitosis

Question 6

Asexual and sexual reproduction are very different methods.
Give four ways in which asexual reproduction is different to sexual reproduction. (12)

Answer 6

asexual vs sexual

• One parent vs. two parents.
• Identical offspring vs. varied offspring.
• No gametes vs. gametes involved.
• Faster vs. slower process.
• Simple vs. complex reproduction.
• No fertilization vs. requires fertilization.
• Common in bacteria/plants vs. animals/plants.
• Less energy needed vs. more energy needed.
• No genetic diversity vs. promotes diversity.
• Produces clones vs. unique offspring.
• Suited for stable environments vs. changing environments.
• Limited evolution vs. faster evolution.

Question 7

where in the body does meiosis takes place?

Answer 7

In the testes (males) and ovaries (females).

Question 8

what happens to the DNA at the very start of meiosis, before the cell starts to divide?

Answer 8

The DNA is replicated, forming identical copies called sister chromatids.

Question 9

How many cell divisions are there during the process of meiosis ?

Answer 9

two

Question 10

Briefly describe the result of meiosis

Answer 10

Meiosis results in four genetically different haploid cells (gametes), each with half the number of chromosomes of the original cell.

Question 11

How many copies of each chromosomes does the resulting cell have?

Answer 11

The resulting cell has one copy of each chromosome.

Question 12

After the two gametes join to produce a fertilised egg, the cells divide repeatedly.
What type of cell division do these cell undergo?

Answer 12

mitosis

meiosis is for making gametes, while mitosis is for the growth and development of the fertilized egg into an organism.

Question 13

The dividing cells form an embryo.
What happens to the cells in the embryo as it develops in order to form the whole organism

Answer 13

As the embryo develops, the cells differentiate into various specialized cell types to form the tissues and organs of the organism.

Question 14

tell me about malaria sexual and asexual reproduction.

Answer 14

• Asexual reproduction in humans, where the parasite multiplies in red blood cells.
• Sexual reproduction in mosquitoes, where the parasite reproduces in the mosquito’s gut.

Question 15

Daffodils can reproduce by producing seeds or bulbs. Bulbs divide to form new plants.
What type of reproduction is shown when the bulb divide to produce new plants?

Answer 15

asexual reproduction

Question 16

state 2 advantages of asexual reproduction over sexual reproduction

Answer 16

1. Faster reproduction.
2. No need for a mate.

Question 17

An unfavourable environmental change affects a population of organisms .
Explain why sexual reproduction increases the chance of the population surviving.

Answer 17

Sexual reproduction increases genetic variation, which helps the population adapt to the unfavorable environmental change by producing individuals with different traits, some of which may be better suited to survive.

Question 18

how many chromosomes are there in a normal body cell?

Answer 18

46 chromosomes (23 pairs)

Question 19

How can you tell that the allele for the disease is not dominant?

Answer 19

• it’s represented by a lowercase letter
• If the disease allele is not dominant, it means the person would need to inherit two copies of the allele (one from each parent) for the disease to appear. If only one copy is inherited, the person won’t have the disease.

Question 20

what are the symptoms of polydactyly?

Answer 20

having extra fingers or toes on the hands or feet.

Question 21

A person only has to have one allele for polydactyly to have symptoms.
What does this tell you about the allele that causes polydactyly?

Answer 21

that the allele for polydactyly is dominant, as only one copy of the allele is needed for the symptoms to appear.

Question 22

Even if both parents each carry one copy of the allele that causes cystic fibrosis, there is only a relatively small chance that their offspring will have the disorder. Explain why this is the case.

Answer 22

since it’s a recessive disorder, their offspring must inherit two copies of the recessive allele (one from each parent, “ff”) to have the disorder. This means there is a 25% chance of the child having cystic fibrosis.

Question 23

suggest 3 arguments against embryo screening

Answer 23

Ethical concerns: It may lead to “designer babies” and discrimination against embryos with disabilities.

Cost: Embryo screening is expensive and may not be accessible to everyone.

Emotional impact: Deciding to discard embryos can be emotionally challenging for parents.

Question 24

suggest 3 arguments for embryo screening

Answer 24

Prevents genetic disorders: Reduces the risk of inherited diseases like cystic fibrosis.

Improves quality of life: Ensures healthier children and families.

Informed choices: Helps parents make decisions based on genetic information.