Consider statements about plant biology: 1. Phototropism is growth towards light. 2. Geotropism is growth in response to gravity. 3. Thigmotropism is growth in response to water. Which are correct? MCQ with Answer and Explanation

Explanation:
Biopesticides, such as Bacillus thuringiensis (Bt), neem extracts, and Trichoderma, are generally target-specific, affecting only certain pests while sparing beneficial organisms, humans, and the environment. They are biodegradable and do not accumulate. Chemical pesticides often kill a wide range of species, persist, and cause pollution. Biopesticides are key in Integrated Pest Management (IPM).

Explanation:
Chiasmata become clearly visible during the diplotene stage of Prophase I. While the actual exchange of genetic material (crossing over) occurs during the pachytene stage, the homologous chromosomes begin to repel each other and move apart in diplotene, remaining connected only at the sites of crossing over, which appear as X-shaped chiasmata. Exam tip: Pachytene = crossing over; Diplotene = chiasmata visible.

Explanation:
The carpel is the female reproductive organ of a flower, consisting of the ovary, style, and stigma; the stigma is the terminal, sticky receptive surface where pollen grains land and germinate. The stamen is the male reproductive organ, consisting of the filament and the anther; the anther is the terminal sac where pollen grains (male gametophytes) are produced. After fertilization, the ovule develops into the seed, while the ovary wall matures and develops into the fruit. Thus, statements 1 and 2 are correct.