Revision BiologyPollination & Fertilization

IX Std

Dr. Pramila Kudva

Agents of cross pollination

Across4. pollinated by

elephants

Down1. pollinated by insects2. pollinated by water3. pollinated by wind5. pollinated by birds

Across2. structural barriers for pollination

4. anthers mature early7. anthers and styles are located at different levels Down1. cross pollination3. self pollination where pollen is deposited on the stigma of a different flower4. stigma matures early5. Self pollination6. different maturation time for the anthers and style

1. Draw the pollen as shown below and neatly label the parts

1

2

34

5

2. Draw the mature ovule and label the parts.

65

3 b4

3 a

2

1

7

Part of the Flower After fertilization

Ovary

Ovary Wall

Ovule

Placenta

Integuments

Secondary nucleus

Egg Cell

Name the changes in the part of the flower after fertilization.

Slide 1 Answers: Across

4 – ElephophilousDown

1. Entomophilous2. Hydrophilous3. Anemophilous5. Ornithophilous

Slide 2 Answers: 1 – Pit

2 – Exine3 – intine

4 –Pollen tube nucleus5 – Generative nucleus

Slide 3 Answers: 1. Antipodal cells2. Polar nuclei3. a & b – Integuments4. Egg cell5. Micropyle6. Synergids7. Embryo sac

Slide 5 Answers: 1.Fruit2, Pericarp3. Seed4. Stalk of the seed5. Seed coat6. Endosperm [Food storing tissue]7. Zygote

Slide 4 Answers: 1. Antipodal cells2. Polar nuclei3. a & b – Integuments4. Egg cell5. Micropyle6. Synergids7. Embryo sac

1. What is Triple fusion

Ans: two polar nuclei [2N] unite to form a seccondary nucleus and this unites with the sperm cell [1N] to form the endosperm [3 N].

2. What is the function of the following:

a) Endosperm Ans: It provides nutrition to the seed. It contains

protein and starch

b) Tube of the pollen Ans: To take the male gametes to the embryo sac

3. What is double fertilization?

Ans: a) Egg cell unites with a male gamete / Sperm Cell [2 N] – Forms the Zygote

b) 2 Polar Nuclei fuse with one male gamete /sperm cell [3 N] – Forms the Endosperm Nucleus / Secondary nucleus

4. Name the following:

a) A) The nourishing liquid that holds the seeds

b) Ans: Placenta

b) Different maturation time of the androecium and gynoecium

Ans: dichogamy

c) Anthers mature earlier

Ans: Protandry

d) Stigma matures earlier

Ans: Protogyny

e) Mechanical barrier that favours cross pollination

Ans: Herkogamy

f) Anthers and stigma grow at different heights

Ans: Heterostyly

5. What is the difference between Autogamy and Geitonogamy?

Autogamy is pollination in the same flower

Geitonogamy is pollination between the flowers of the same plant but different flowers.

6. In which pollination do you find

a) Floating Pollen

Ans: Hydrophilous

b) Stigma hanging outside the flower

Ans: Anemophilous

c) Flowers with nectar

Ans: Entomophilous

d) Large flowers on the ground

Ans: Elephophilous

e) Bright flowers without nectar

Ans: Ornithophilous

Give one word for the following.

A) Pollen grain of the flower fail to fertilize the egg cell of the same flower.

Ans: Self sterility

B) Grooves on the petals that lead to nectaries

Ans: Honey guides or nectary guides

C) Transference of pollen to the stigma of a different flower on the same plant

Ans: Geitonogamy