Human Health and Disease — BIOLOGY STD 12 Science — Question

If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?

The following is the illustration of the sequence of ovarian events (a – i) in a human female.

Specify the endocrine function of corpus luteum. How does it influence the uterus? Why is it essential?

Study the diagram given below showing the modes of pollination. Answer the questions that follow.

i. The given diagram shows three methods of pollen transfer in plants. What are the technical terms used for pollen transfer methods 1, 2 and 3?
ii. How do the following plants achieve pollination successfully?
1. Water lily
2. Vallisneria
iii. Flowering plants have developed many devices to avoid inbreeding depression. Explain one hereditary and one physiological device which helps plants to achieve this target.

Given below is a table showing the genotypes and the phenotypes of blood groups in the human population.

Genotype	Phenotype
W	Y
IB IO	Z
IA IB	O
X	O

1. Identify the genotype Wand X, and the phenotype Y and Z.
2. Name the pattern of inheritance exhibited by the phenotypes Y and Z in the table.

What are ecological pyramids? Mention its limitations.

What are the three types of ecological pyramids. What information is conveyed by each pyramid with regard to structure, function and energy in the ecosystem.

Try to trace the various components of human evolution (hint: brain size and function, skeletal structure, dietary preference, etc.)

The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form:

1. MALT.
2. CMI.
3. AIDS.
4. NACO.
5. HIV.

Fitness is the end result of the ability to adapt and get selected by nature. Explain with suitable example.

Explain the causes of Biodiversity loss?