Reproduction in Plants

Question 1

Define Asexual reproduction

Answer 1

Process of producing a

• GENETICALLY IDENTICAL OFFSPRING
• from ONE PARENT
• WITHOUT THE FUSION OF GAMETES

Question 2

State 4 advantages of self-pollination.

• beneficial qualities
• dependence
• likely to take place
• requirement

Answer 2

1. All BENEFICIAL QUALITIES are passed onto the offspring from parent plant
2. Not dependent on external agents of pollination such as insects or wind for pollination
3. Most likely to take place as stigmas are closer to anthers
4. Only one parent required

Question 3

What is sexual reproduction?

Answer 3

Production of

• GENETICALLY DISSIMILAR OFFSPRING
• involving the FUSION OF NUCLEI OF GAMETES
• to form a DIPLOID ZYGOTE

Question 4

What are the male reproductive organs?

Answer 4

Anther and filament

Question 5

State the function of anther.

Answer 5

It contains

• 2 lobes and a vascular bundle
• Each lobe contains 2 POLLEN SACS containing THE MALE GAMETES, POLLEN GRAINS

Question 6

What is the function of filament?

Answer 6

Stalk that HOLDS THE ANTHER in a suitable position to DISPERSE pollen

Question 7

What are the female reproductive organs in flower?

SOS

Answer 7

Carpel

• Stigma
• Ovary
• Style

Question 8

State the function of stigma.

Answer 8

Secretes a sugary fluid that STIMULATES GERMINATION of pollen grains

Question 9

What is the function of ovary?

Answer 9

Contain one or more OVULES,which contains FEMALE GAMETES

Question 10

State the function of style.

Answer 10

HOLD the stigma in position TO TRAP POLLEN GRAINS

Question 11

State the function of SEPAL.

Answer 11

they ENCLOSE AND PROTECT THE FLOWER when in BUD STAGE

Question 12

What are the 2 functions of petals?

Answer 12

1. LARGE and BRIGHTLY COLOURED to attract insects in insect-pollinated plants
2. provides a PLATFORM for insect to land on

Question 13

Define self-pollination.

Answer 13

• TRANSFER OF POLLEN GRAINS
• from the ANTHER TO THE STIGMA
• OF THE SAME FLOWER OR A DIFFERENT FLOWER IN A SAME PLANT

Question 14

State and explain 2 factors favouring self-pollination.

• sexuality
• position

Answer 14

S1: BISEXUAL with anthers and stgimas MATURING AT THE SAME TIME
EXP; HENCE POLLEN GRAINS ARE READY to pollinate the stigma

S2: Stigma is situated DIRECT BELOW THE ANTHER
EXP: allowing pollen grains to fall onto it

Question 15

Explain 2 disadvantages on self pollination

Answer 15

1. LESS GENETIC VARIATION
   - hence, offspring is LESS ADAPTED to environmental changes
2. Offspring produced are GENETICALLY SIMILAR to parents causing fewer varieties of offspring

Question 16

Define cross-pollination.

Answer 16

The TRANSFER OF POLLEN GRAINS from ANTHER TO THE STIGMA of the flower of another plant of the same species

Question 17

State and explain 3 factors favouring cross-pollination.

Answer 17

1. When plants bear only male and female flowers, hence self-pollination is impossible
2. In plants with bisexual flowers, the anthers and stigmas mature at different times, making self-fertilisation impossible
3. In bisexual plants, stigmas of plants may situated at a distance away from the anthers.
   making it less possible for pollen of same plant to land on stigma and self-pollination to occur

Question 18

State 2 disadvantages of cross-pollination

Answer 18

1. energy consuming. A lot of energy is required to make large amounts of pollen grains
2. Dependent on external agents of pollination such as insects or wind for pollination