Heredity and Evolution — Science STD 10 — Question

Name the reproductive parts of an angiosperm. Where are these parts located? Explain in brief the structure of its female reproductive parts.

What eye defects hypertrophies? Describe with ray diagram how this defect of vision can be corrected by using an appropriate lens?

Mention why is it not possible to make use of solar cells to meet all our energy needs? State three reasons to support your answer. Also, mention three uses of solar cells.

Some of the important fossils which have been studied are those of organisms X, Y and Z. X were marine arthropods which were common between 400 to 600 million years ago. Y were the invertebrate animals (molluscs) with a flat, coiled, spiral shell which lived in the sea about 180 million years ago. Z are the extinct carnivorous or herbivorous reptiles which appeared on the earth about 250 million years ago and became extinct about 65 million years ago. What are X, Y and Z?

Write one main difference between asexual and sexual mode of reproduction. Which species is likely to have comparatively better chances of survival – the one reproducing asexually or the one reproducing sexually? Give reason to justify your answer.

Indicate the flow of energy in an ecosystem. Why is it unidirectional? Justify.

Why is variation beneficial to the species but not necessarily for the individual?

1. Name the following:

1. Thread like non-reproductive structures present in Rhizopus.
2. 'Blobs' that develop at the tips of the non-reproductive threads in Rhizopus

2. Explain how these structures protect themselves and what is the function of the structures released from the 'blobs' in Rhizopus.