Mitosis and Meiosis

Question 1

Definition of asexual reproduction

Answer 1

• One parent produces genetically identical offspring
• asexual reproduction involves mitosis

Question 2

Definition of mitosis

Answer 2

A type of cell division where one parent cell produces two daughter cells which are genetically identical and contain the same number of chromosomes as the parent cell

Question 3

Importance of mitosis

Answer 3

1. Growth of multicellular organisms by producing more cells
2. Repair of tissues by replacing damaged cells
3. Asexual reproduction

Question 4

Why do we need to produce genetically identical cells with mitosis?

Answer 4

1. To ensure proper development of the zygote/embryo
2. To prevent changes in the sequence of bases of a gene/ gene mutations during DNA replications which can cause
   a. a different and abnormal protein to be produced b. may lead to an uncontrolled division of cells

Question 5

Advantages of asexual reproduction

Answer 5

1. Only one parent is required
2. All the beneficial qualities are passed on to offspring
3. Faster than sexual reproduction

Question 6

Disadvantages of asexual reproduction

Answer 6

1. No genetic variation in offspring thus species are not adapted well to changes in the environment

Question 7

Definition of sexual reproduction

Answer 7

1. The fusion of two gametes to form a zygote
2. Produces genetically dissimilar offspring

Question 8

Definition of meiosis

Answer 8

A type of cell division where one parent cell produces four daughter cells which are genetically dissimilar and contain the half the chromosome number of the parent cell (it is halved due to reduction division)

Question 9

Importance of meiosis

Answer 9

1. Production of haploid gametes
   - occurs in gamete-producing cells
   - in animals: testes and ovary
   - in plants: anther and ovule
   - for sexual reproduction. When the nucleus of the haploid male gamete fuses with the nucleus of the haploid female gamete, the normal diploid number of chromosomes is restored in the zygote
2. Gametes produced are genetically dissimilar
   - greater genetic variation in species help the species to be better adapted to changes in the environment

Question 10

Advantages of sexual reproduction

Answer 10

1. Offspring may inherit beneficial qualities from both parents
2. There is a genetic variation in the offspring, making the species better adapted to changes in the environment

Question 11

Disadvantages of sexual reproduction

Answer 11

1. Two parents are required
2. Fusion of gametes is required
3. Slower than asexual reproduction