Sexual Reproduction in Flowering Plants — BIOLOGY STD 12 Science — Question

Mention the location and the function of Leydig cells in humans.

1. Draw a diagram of a sectional view of a monocot seed (grain).
2. Label and write the function of: Coleoptile, Coleorrhiza, Endosperm.

Explain antibiotic resistance observed in bacteria in light of Darwinian selection theory.

During an excursion to a botanical garden, the teacher shows an old tree, which was on the verge of extinction. As soon as the teacher advanced with the students, some enthusiastic students climbed up the tree and started cutting the branches, collecting its leaves as precious collection. Rajesh instead took photographs of the tree from various angles. The boys mocked at Rajesh while the teacher appreciated him.

1. How can biodiversity be conserved?
2. What international initiatives were taken to conserve biodiversity?
3. What values did Rajesh possess?

To which category of cells do B-cells and T-cells belong? How do they differ from each other with reference to their formation and response to antigens?

Differentiate between carnivores and consumers.

When Morgan conducted a dihybrid cross on Drosophila like Mendel did with pea plants, the F, ratios deviated significantly from that of Mendels F, ratio. Write the explanation Morgan and his group gave for the observations they obtained from their experiments.
Or
Morgan carried out several dihybrid crosses in Drosophila and found F, ratios deviated very significantly from the expected Mendelian ratio. Explain his findings with the help of an example.

Explain artificial synthesis of the compound used by diabetic patients.

Name the group of bacteria involved in setting milk into curd. Explain the process they carry in doing so. Write another beneficial role of such bacteria.

How has the use of Agrobacterium as vectors helped in controlling Meloidegyne incognitia infestation in tobacco plants? Explain in correct sequence.