BIOLOGY 2 Marks Questions

i. Photorespiration.
ii. Yes, because by consuming oxygen at a higher temperature, it protects the chlorophyll from photo-oxidation.

Need for Biological Classification:
• To study and include each organism along with its identification and habitat.
• To establish the relationship among different organisms and to know about their evolution.

a. Exocrine glands. These glands have ducts. They secrete their secretions through ducts.
b. Endocrine glands. Endocrine glands do not have ducts. They directly secrete their secretions.
c. Hormone. Hormones are non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts.

Difference between Kinocilia and Stereocilia:

Kinocilia	Stereocilia
i.These are motile in nature.	These are non-motile in nature.
ii. These arise from a cytoplasmic basal granule.	These are evaginations of the plasma membrane.
iii. These are present on epithelial cells of respiratory and genital tracts.	These are present in the epithelial cells of epididymis and vasa deferentia of man.

In dicot stems, the cells of cambium present between the primary xylem and primary phloem are the intrafascicular cambium. The cells of medullary rays, adjoining this intrafascicular cambium become meristematic and form the interfascicular cambium. Interfascicular and intrafascicular cambium together form a ring of cambium called cambium ring.