NEET Practice Questions (MCQs) with Answers & Solutions

While not explicitly stated in the provided text, the NCERT context leads to the understanding that sexual reproduction in flowering plants culminates in fruits and seeds. The ovule, after fertilization, develops into the seed. This is a fundamental concept in plant reproduction.

Pollen grains are male gametophytes, formed before fertilization. The embryo, endosperm, and seed are all products of successful fertilization and subsequent developmental changes.

The zygote's dormancy (or lack thereof) is directly related to its subsequent development into an embryo. Therefore, this question points towards the process of embryo development as a significant post-fertilization event.

The text states: 'an amazing range of adaptations to ensure formation of the end products of sexual reproduction, the fruits and seeds.' This clearly identifies fruits and seeds as the ultimate products.

The table of contents clearly lists '1.4 Post-fertilisation: Structures and Events' as the relevant section.

Post-fertilization, the zygote develops into the embryo, the primary endosperm nucleus develops into the endosperm, and the integuments harden to form the seed coat, all contributing to the formation of the seed from the ovule.

The question 'Differentiate between: (c) integument and testa;' indirectly refers to the transformation of integuments into the testa (seed coat) as a post-fertilization event. This is a standard concept in plant reproduction.

According to the NCERT text, 'However, it may be remembered that rotation around a C-C single bond is not completely free. It is hindered by a small energy barrier of 1-20 kJ mol$^{-1}$ due to weak repulsive interaction between the adjacent bonds.' Therefore, the statement that rotation is completely free is incorrect.

The NCERT text states, 'It is hindered by a small energy barrier of 1-20 kJ mol$^{-1}$ due to weak repulsive interaction between the adjacent bonds. Such a type of repulsive interaction is called torsional strain.'

The NCERT text defines this: 'One such conformation in which hydrogen atoms attached to two carbons are as closed together as possible is called eclipsed conformation and the other in which hydrogens are as far apart as possible is known as the staggered conformation.'