Pollen grains are generally spherical measuring about 25-50 micrometers in diameter. It has a prominent two-layered wall. The hard outer layer called the exine is made up of sporopollenin which is one of the most resistant organic material known. The inner wall of the pollen grain is called the intine. It is a thin and continuous layer made up of cellulose and pectin. The innermost wall layer is the tapetum. It nourishes the developing pollen grains.
English
50 Questions
200 Marks
45 Mins EnglishRead the given statements. Choose the correct set of code that represents two correct statements:
A. During embryogeny, suspensor is an ephemeral structure found at the radicular end of embryo-sac.
B. During grass-embryo development, a very large suspensor is formed.
C. Suspensor attains maximal size at globular/heart-shaped stage of embryo development in a dicot ovule/seed.
D. Suspensor does not plays an important nourishing role during initial stages of new seedling formation.
Choose the correct sequence of events in a mango ovule leading to development of a diploid embryo via diplospory:
Based on the observation of different flowers in a garden, which of the following would provide the understanding that a flower can be self-pollinating?
(1) Cleistogamous flower whose petals do not open at all.
(2) Flowers in which stamens and carpels mature at different times in the same flower.
(3) An open flower in which anthers of stamens and stigma of carpel lie at the same level.
Codes:
What happens to a pollen grain first after it is transferred on a stigma?
Which of the following parts of a flower develops into a fruit after fertilisation?
