Chapter 15: Modes of reproduction

Question 1

Asexual reproduction

Answer 1

• the process that results in production of genetically identical offspring from one parent, without the fusion of gamates

Question 2

Mitosis

Answer 2

• a types of cell division giving rise to genetically identical cells in which chromosome number is maintained

Question 3

Process of mitosis

Answer 3

• parent cell has 4 chromosomes
• chromosomes in parent cell duplicates
• the parent plant split into 2 genetically identical daughter cells

Question 4

Why is mitosis

Answer 4

• it allows asexual reproduction to occur
• it allows multicellular organisms to grow
• it allows damaged tissues to be repaired

Question 5

Advantages of asexual reproduction

Answer 5

• only one parent plant is required
• fusion of gametes is not required
• all the beneficial quantities are passed on to the offspring
• this method of offspring production is faster than sexual reproduction

Question 6

Disadvantages of asexual reproduction

Answer 6

• there is no genetic variation in offspring hence offsprings are not well-adapted to changes to environment, which can cause entire population of organism to be wiped out by diseases they are not resistant to

Question 7

Sexual reproduction

Answer 7

• the process involving the fusion of 2 gametes to form a zygote. it produces a genetically dissimilar offspring

Question 8

Homologous chromosomes

Answer 8

• chromosomes that are of the same shape size and have same sequence of genes
• in meiosis, the parent cell has 2 pairs of homologous chromosomes

Question 9

Meiosis

Answer 9

• a type of cell division that gives rise to genetically dissimilar cells in which the chromosomes number is halved due to the separation of homologous chromosomes

Question 10

Process of meiosis

Answer 10

• parent cell have 2 pairs of homologous chromosomes
• parent cell split into 4 genetically dissimilar daughter cells
• each daughter cell has 2 chromosomes, within each pair of chromosomes in parent cell, each enters different daughter cells

Question 11

Haploid cell

Answer 11

• a cell with 1 set of chromosomes

Question 12

Diploid

Answer 12

• a cell with 2 sets of chromosomes

Question 13

Why is meiosis important

Answer 13

• produces hypoid gametes (sex cell). Hence, during fertilisations, when nucleus of male gamete fuse with nucleus of female gamete, the normal diploid number of chromosomes is restored in zygote
• it produces gametes that are genetically dissimilar. the greater the genetic variation, the better the species is adapted to changes in the environment. A change in environment won’t wipe out entire population and those that survive pass on favourable genes to offsprings

Question 14

Advantages of sexual reproduction

Answer 14

• offspring may inherit beneficial qualities from both parents
• there is genetic variation in offspring that is better adapted to changes in environment

Question 15

Disadvantage of sexual reproduction

Answer 15

• requires 2 parents (except in plants with bisexual flowers)
• fusion of gametes is required
• this method of producing offsprings is slower than asexual reproduction

Question 16

Differences between asexual and sexual reproduction

Answer 16

• asexual does not involve fusion of gametes, while sexual requires fusion of male gamete with female gamete to form a zygote
• asexual requires 1 parent, while sexual requires 2
• offsprings are genetically identical to parent in asexual, while offsprings are genetically dissimilar to parents in sexual
• asexual is a quicker method of producing offspring than sexual