15 | Reproduction in Plants

Question 1

Definition of reproduction?

Answer 1

Reproduction is the process of producing new organisms.

Question 2

Definition of asexual reproduction?

Answer 2

Asexual reproduction is the process resulting in the production of genetically identical offspring from one parent, without the fusion of nuclei of haploid gametes.

Question 3

Definition of sexual reproduction?

Answer 3

Sexual reproduction is the process involving the fusion of nuclei of the haploid female gamete and the haploid male gamete to form a diploid zygote and the production of genetically dissimilar offspring.

Question 4

Differences between asexual and sexual reproduction?

Answer 4

SPOF

Question 5

What is the sepal?

Answer 5

• Modified leaf which enclose and protect the other parts of the flower in the bud stage
• All sepals together make up the calyx

Question 6

What is the petal?

Answer 6

• Brightly coloured and conspicuous modified leaves to attract insects for pollination and provide a platform for insects to land
• All petals together make up the corolla

Question 7

What is the receptacle?

Answer 7

Enlarged end of the flower stalk

Question 8

What is the pedicel

Answer 8

Flower stalk

Question 9

What is the stamen

Answer 9

male part of the flower
consists of
- filament
- anther

Question 10

What is the filament

Answer 10

Holds anther in a suitable position to disperse pollen grain

Question 11

What is the anther

Answer 11

• produces pollen grain
• has 2 lobes
  – each contain 2 pollen sacs, which produces pollen.
  — pollen grains are haploid as they are produced by meiosis
  — the nucleus in the pollen grain is the male gamete (?)

Question 12

What is the carpel?

Answer 12

• Female part of the flower
• Consists of one or more stigmas - consists of a style
• consists of an ovary

Question 13

Function of the stigma?

Answer 13

Capture pollen grains

Question 14

Function of the style?

Answer 14

Holds stigma at a suitable position to trap pollen grains and through which pollen tube grows

Question 15

Function of ovary?

Answer 15

• Produces and protects 1 or more ovules
• Ovary will develop into a seed after fertilisation. It produces the haploid female gamete or ovum by meiosis
• The ovum is in the ovule.

Question 16

Define pollination

Answer 16

Pollination is the transfer of pollen grains from the anther to the stigma

Question 17

Define self-pollination

Answer 17

Self pollination is the process whereby the pollen grains from the anther are transferred to the stigma of the same flower or a different flower on the same plant.

Question 18

Advantages of self-pollination?

Answer 18

WELPQ
- less pollen and energy is Wasted (W)
- not dependent on External factors for pollination (E)
- more Likely to take place since stigmas are closer to anthers (L)
- only one Parent is required (P)
- beneficial Qualities are passed down from parent plant to offspring (Q)

Question 19

Disadvantages of self-pollination?

Answer 19

GPD
- offspring produced are Genetically similar to parents causing fewer varieties of offspring, less adapted to changes in the environment (G)
- Probability of harmful recessive alleles being expressed in the offspring is higher as compared with cross-pollination (P)
- species may become weaker, smaller and less resistant to Disease (D)

Question 20

Ways to prevent self pollination?

Answer 20

MUAF
- stamen and pistil Mature at different times (M)
- Unisexual plant [plant producing either male of female flowers] (U)
- stigma of the flower is Above the anther (A)
- stigma and anther are situated Far apart from each other (F)

Question 21

Define cross-pollination

Answer 21

Cross-pollination is the process of pollination whereby the pollen grains from the anther are transferred to the stigma of another flower on another plant of the same species.

Question 22

Advantages of cross-pollination?

Answer 22

QVSPH
- offspring can inherit beneficial qualities from both parents (Q)
- more varieties of offspring are produced which leads to greater genetic variation (V)
- Seeds produced are capable of surviving longer before germination takes place (S)
- probability of harmful recessive alleles being expressed in offspring is lower as compared with self-pollination (P)
- increased probability of offspring being heterozygous (H)

Question 23

Disadvantages of cross-pollination

Answer 23

PEWL
- Two different plants of the same species are required (P)
- Dependent on external factors for pollination (E)
- More pollen and energy wasted (W)
- Less likely to occur as compared to self-pollination (L)

Question 24

What occurs during insect pollination?

Answer 24

notes

Question 25

an example of an insect pollinated flower?

Answer 25

clitoria flower

Question 26

describe the example of the insect pollinated flower?

Answer 26

notes

Question 27

what occurs during wind pollination

Answer 27

- the long pendulous filaments expose the anthers to the wind - when the wind blows, pollen grains are released and carried away by the wind - the pollen grains land on large and feathery stigma, which has a large SA to trap the pollen grain

Question 28

an example of a wind pollinated flower

Answer 28

Ischaemum muticum

Question 29

describe the example of the wind pollinated flower

Answer 29

notes

Question 30

things to compare for insect-pollinated and wind-pollinated flowers

Answer 30

PPNNSSS - petals - pollen - nectar guide - nectar - stigma - stamen - scent comparison in notes

Question 31

process of fertilisation

Answer 31

notes