Human Reproduction — BIOLOGY STD 12 Science — Question

Define species-area relationship pattern of biodiversity in detail.

What is geitonogamy? Give an example. How does geitonogamy differ from xenogamy in plants?

1. The graph below represents the growth patterns of two types of aquatic organisms over a brief period of time in a water body, surrounded by agricultural land, extensively supplied with fertilisers. Identify the organisms that would represent: (i) A and (ii) B.
2. State the reason for such a change in the water body and also write the term given to it.

1. How are Mendelian inheritance, polygenic inheritance and pleiotropy different from each other?
2. Explain polygenic inheritance pattern with the help of a suitable example.

1. What is an age pyramid?
2. Explain with the help of figures, the three different types of age pyramids represented by human population.

Given below is the diagram of a human ovum surrounded by a few sperms. Observe the diagram and answer the following questions:
Compare the fate of sperms shown in the diagram.

Describe the consumptive use value of biodiversity as food, drugs and medicines, fuel and fiber with suitable examples.

With a neat, labelled diagram, describe the parts of a mature angiosperm embryo sac. Mention the role of synergids.

'Modern methods of breeding animals and plants can alleviate the global food shortage'. Comment on the statement and give suitable examples.

Answer the following questions:
Explain the changes the primary oocyte undergoes while in different follicular stages before ovulation.