Biology
Cross-pollination is considered better than self-pollination because it produces healthier and more viable seeds. But it cannot occur by itself. Cross-pollination occurs with the help of certain agents like wind, water, insects, etc. Which of the following features of flowers are not suitable for insect-pollination ?
P. Flowers are usually small and of dull colours.
Q. Flowers are not scented and do not produce nectar.
R. Flowers produce sticky pollen grains.
- Only Q
- Only Q and R
- Only P and R
- Only P and Q
Answer
Only P and Q
Reason — Insect-pollinated flowers are usually large, brightly coloured, scented and nectar-producing. They also produce sticky pollen grains so that the pollen can stick to the body of insects.
Small and dull-coloured flowers are not suitable because insects are not attracted to them. Flowers with no scent and no nectar are also not suitable because they do not attract insects.
Related Questions
Flowers borne on the shoot system of a plant serve as reproductive part. Which of the following reasons supports this statement ?
P. Flowers bear stamens and carpels.
Q. Flowers make the plant attractive.
R. Flowers produce fruits with seeds.- Only P
- Only Q
- Only P and R
- Only Q and R
Mamta is curious to study different kinds of pollination among flowers present in her garden. She has performed artificial pollination in the following ways :
P. Pollination within a flower.
Q. Pollination between flowers of same plant.
R. Pollination between two flowers of two different plants of same species.
S. Pollination between two flowers of two different plants of the different species.Which of the ways given above explains 'cross-pollination'?
- Only R
- Only P, Q and S
- Only P, R and S
- Only P and S
Assertion (A): Carrot is a biennial plant which stores food material in its roots in the first year.
Reason (R): This food is utilized in the second year to produce flowers and viable seeds, i.e. to reproduce sexually.
- 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): Calyx is the outermost whorl of a flower which consists of large, fragrant and brightly coloured petals.
Reason (R): As petals are brightly coloured and fragrant, they can be noticed by insects easily and help in cross pollination.
- 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.