Biology
Shaista is working on her school project about plant reproduction. Her teacher Mrs. Aggrawal gave her the task of investigating pollination in pea flower, a common garden plant. Shaista is curious to know how pollination in pea flower and maize flower differs from each other.
(a) Is pollination a necessary event before fertilization for reproduction in plants? Explain.
(b) What are the pollinating agents for pea and maize flowers respectively?
(c) Write scientific terms for the kind of pollination found in pea flower and maize flower on the basis of pollinating agents.
(d) Mention the technical term for the specific condition of stamens in pea flower.
(e) What are the two advantages of cross-pollination?
Answer
(a) Yes, pollination is a necessary event before fertilization in flowering plants. Pollen grains must first reach the stigma so that the pollen tube can form and carry the male gametes to the ovule for fertilization.
(b) Pea: No external pollinating agent required because self-pollination occurs.
Maize: Wind
(c) The scientific term for pollination in pea flower is entomophily and for maize flower is anemophily.
(d) The technical term for the specific condition of stamens in pea flower is diadelphous.
(e) The two advantages of cross-pollination are:
It produces genetic variation in offspring.
It results in healthier and more vigorous plants.
Related Questions
Assertion (A): Herkogamous flowers favour cross-pollination as these flowers have a structural barrier between the male and female reproductive parts.
Reason (R): Pansy is an example of a herkogamous flower which has a hood covering the stigma.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Entomophilous flowers are brightly coloured and often scented.
Reason (R): The pollinating agents of entomophilous flowers are insects which usually get attracted towards the bright colours or scents of the flowers.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): One polar nucleus fuses with two sperm nuclei of a flower and develop into an endosperm during the process of fertilization.
Reason (R): The large central cell of the embryo sac contains two polar nuclei, which fuse with one male nucleus. This process is termed as 'triple fusion'.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): The process of removal of anthers in young flowers is termed as 'emasculation'.
Reason (R): Emasculation is mainly performed during artificial pollination to produce the desired variety of the plants.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.