The cell wall of a pollen grain is formed of two layers, outer exine and inner intine. The exine is the hard layer and is made up of sporopollenin (one of the most resistant organic materials known). It can withstand high temperatures, strong acids, and alkali. No enzyme till now is known that can degrade sporopollenin so far, that’s why they are well preserved as fossils.
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?
