Reproduction in organisms — BIOLOGY STD 12 Science — Question

A cross was carried out between two pea plants showing the contrasting traits of height of the plant. The result of the cross showed 50% of parental characters

1. Work out the cross with the help of a Punnett square.
2. Name the type of the cross carried out.

Explain briefly:
PCR

A cross between a normal couple resulted in a son who was haemophilic and a normal daughter. In course of time, when the daughter was married to a normal man, to their surprise, the grandson was also haemophilic.
Write the conclusion you draw of the inheritance pattern of this disease.

Common yeast is known as Baker's yeast and also as Brewer's yeast. Justify.

Name the interaction in each of the following:

1. Cuscuta growing on a shoe flower plant.
2. Mycorrhizae living on the roots of higher plants.
3. Clownfish living among the tentacles of sea anemone.
4. Koel laying her eggs in crow’s nest.

A student on a field trip suddenly felt breathlessness and started to sneeze very badly. Name this response and explain what it is due to.

Mention the kind of biodiversity of more than a thousand varieties of mangoes in India represent. How is it possible?

Write any three examples of assisted reproductive technologies.

How do plants produce seeds through apomixis? Explain with the help of an example.

How to Prevent STIs ?###What are the measures one has to take to prevent from contracting STDs?