Chapter 16 - Reproduction

Question 1

Define asexual reproduction.

Answer 1

The process resulting in the production of genetically identical offspring from one parent.

Question 2

What are some examples of asexual reproduction?

Answer 2

Budding (yeast), spore germination (fungi), binary fission (bacteria).

Question 3

What are the advantages of asexual reproduction?

Answer 3

• One parent required.
• Colonises area rapidly.
• Develops from bud to plant rapidly.
• No external agents required.

Question 4

What are the disadvantages of sexual reproduction?

Answer 4

• No genetic variation.
• A disease may affect all in one population.
• Less adaptable to environmental changes.
• Overcrowding, competition.

Question 5

Define sexual reproduction.

Answer 5

The process involving the fusion of the nuclei of two gametes to form a zygote and production of offspring that are genetically different from each other.

Question 6

The nuclei of gametes are ________ while the nucleus of a zygote is _______.

Answer 6

Nuclei of gametes are haploid (23) while the zygote is diploid (46).

Question 7

What are the advantages of sexual reproduction?

Answer 7

• More genetic variation.
• Ability to environmental changes.
• A disease is less likely to affect all in one population.

Question 8

What are the disadvantages of sexual reproduction?

Answer 8

• Time & energy required to find a mate.
• Change due to mutation.
• More than one parent required.
• Very few offsprings produced at a time.

Question 9

What is the name of the male reproductive part of a flower and what does it include?

Answer 9

Stamen:

• Anther
• Filament

Question 10

What is the name of the female reproductive part of a flower and what does it include?

Answer 10

Carpel:

• Stigma
• Style
• Ovary

Question 11

What is the function of the sepal?

Answer 11

Protects flower while it is still a bud.

Question 12

What’s the function of the petals?

Answer 12

Attracts insects for pollination.

Question 13

What’s the function of the stigma?

Answer 13

Sticky surface catches pollen.

Question 14

What’s the function of the anther?

Answer 14

Produces pollen which contains the male nucleus.

Question 15

What’s the function of the ovaries?

Answer 15

Produces female gametes (contained in ovule).

Question 16

Define pollination.

Answer 16

The transfer of pollen grains from the anther to the stigma.

Question 17

What are the characteristics of wind-pollinated flowers?

Answer 17

Petals: small, dull coloured, no nectar guides
Stigmas: Large, feathery
Stamen: Long, slender filaments and anthers are usually outside
Pollen grains: small, dry, light, have smooth surfaces and feathery

Question 18

What are some examples of wind-pollinated flowers?

Answer 18

Grass, papaya

Question 19

What are the characteristics of insect pollinated flowers?

Answer 19

Petals: Bright coloured, Large
Stigma: Small, sticky
Stamen: Short, anthers usually inside
Pollen grains: Heavy, sticky, large, have rough surfaces

Question 20

What are some examples of insect pollinated flowers?

Answer 20

Tomato, orchid

Question 21

Define pollination.

Answer 21

The transfer of pollen grains from the anther to the stigma.

Question 22

Define self-pollination.

Answer 22

The transfer of pollen grains from the anther of a flowert to the stigma of the same flower or a different flower on the same plant.

Question 23

Define cross-pollination.

Answer 23

The transfer of pollen grains from the anther of a flower to the stigma of a flower on a different plant of the same species.

Question 24

What are the advantages of self-pollination?

Answer 24

• Less dependency on external agents.
• Generally needs to produce less pollen grains to ensure pollination.
• Less threat of extinction.

Question 25

What are some disadvantages of self pollination?

Answer 25

• Less genetic variation.
• Weaker offspring
• Less adaptable to changes in environment.

Question 26

What are some advantages of cross-pollination?

Answer 26

• Offspring may have desirable qualities from both parents.
• Greater genetic variability.
• Increased chance of survival of species during change in environment.

Question 27

What are some disadvantages of cross-pollination?

Answer 27

• Greater threat of extinction.
• More pollen grains are generally produced.
• Uncertainty whether pollen grains can reach the stigma.