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

How does a farmer use the dormancy of seeds to his advantage?

Discuss natural selection and artificial selection. What are the implications of the latter on the process of evolution?

Name the two techniques involved in controlled breeding experiments.

A patient showed symptoms of sustained high fever, stomach pain and constipation, but no blood clot in stools. Name the disease and its pathogen. Write the diagnostic test for the disease. How does the disease get transmitted?

Write the use of the following in biotechnology.
Plasmid.

Explain the process of secondary treatment given to the primary effluent up to the point it shows significant change in the level of biological oxygen demand (BOD) in it.

Identify A, B, C and D from the following table regarding respiratory system:

Orgasim	Habitat	Respiratory organ
A	Terrestrial	Tracheal tubes and spiracles
Scorpions	Terrestrial	B
Sponges	C	Plasma membrane
Turtles	Underwater	D

Lung cancer, Pituitary, Spleen, Skin cancer, Cancer of adipose tissue, lymph nodes, Adrenal, Bone tumour.

Column (A Type of cancer)	Column B (Organs affected)
(1) Carcinoma	————–
(2) Sarcoma	————–
(3) Lymphoma	————–
(4) Adenocarcinoma	————–

Where is acrosome present in humans? Write its function.

List the events that lead to biogas production from waste water whose BOD has been reduced significantly