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

Explain the events that follow up to fertilization when the sperms come in contact with the ovum in the fallopian tube of a human female.

Suggest a place where one can go to study coral reefs, mangrove vegetation and estuaries.

Define the term Adaptation. State its two advantages.

Select and rewrite the appropriate disorder of the respiratory system with the given symptom.
(Sinusitis, Emphysema, Silicosis and asbestosis, Laryngitis)
(1)Breakdown of alveoli, shortness of breath.
(2)Inflammation of the sinuses, mucous discharge.
(3)Inflammation of larynx, vocal cord, sore throat, hoarseness of voice, mucous build up and cough.
(4)Inflammation of fibrosis, lung damage.

You have created a recombinant DNA molecule by ligating a gene to a plasmid vector. By mistake, your friend adds exonuclease enzyme to the tube containing the recombinant DNA. How will your experiment get affected as you plan to go for transformation now?

Write the scientific name of the fruit–fly. Why did Morgan prefer to work with fruit–flies for his experiments? State any three reasons.

How do biologists use cross over frequencies to map genes on chromosomes?

1. Explain how to find whether an E.coli bacterium has transformed or not, when a recombinant DNA bearing ampicillin-resistant gene is transferred into it.
2. What does the ampicillin-resistant gene act as, in the above case?

Write the biological (binomial) name of causal organism of the following disease:
Elephantiatis (Filariasis).