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

Explain the function of each of the following:
Germ pores

If a marine fish is placed in a fresh water aquarium, will the fish be able to survive? Why or why not?

If there are two pathogenic viruses, one with DNA and other with RNA, which would mutate faster? And Why?

Give any two similarities between the behaviour of genes (Mendel's factors) during inheritance and of chromosomes during cell division.

How are tobacco plants benefitted when nematode specific genes are introduced into them using certain vectors?

Haemophilia is a sex–linked recessive disorder of humans. The pedigree chart given below shows the inheritance of haemophilia in one family. Study the pattern of inheritance and answer the questions given.

1. Give all the possible genotypes of the members 4, 5 and 6 in the pedigree chart.
2. A blood test shows that the individual 14 is a carrier of haemophilia. The member numbered 15 has recently married the member numbered 14. What is the

Name and explain the types of barriers of innate immunity, where some cells release interferons when infected.

Draw a labelled diagram of a section through ovary.

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.
Represent this cross in the form of a pedigree chart. Give the genotypes of the daughter and her husband.

What are the characteristic features of a true–breeding line?