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

State the difference between the first trophic levels of detritus food chain and grazing food chain.

Differentiate between codon and an anticodon.

Name the enzyme produced by Streptococcus bacterium. Explain its importance in medical sciences.

It is supposed that apomixis is a type of asexual reproduction. Explain.

How do ecologists estimate the total number of species present in the world?

Tell about other methods of introducing foreign DNA into host cells.

(a) Name the causative agent of typhoid in humans.
(b) Name the test administered to confirm the diseases.
(c) How does the pathogen gain entry into the human body? Write the diagnostic symptoms and mention the body organ that gets affected in severe cases.

Are there any homologous organs in male and female reproductive system? If yes, give examples.

Which type of conservation measures, in situ or ex-situ, will help the larger number of species to survive? Explain.

A cross was carried out between two pea plants showing the contrasting traits of heightof 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.