Board Paper of Class 12-Science 2006 Biology (SET 1) - Solutions

What is haemocoel?

What do you call the study of the timing of seasonal activities of plants in relation to change in environmental conditions?

What happens to the glycogen concentration in the liver cells when the concentration of adrenaline in the blood stream increases?

Name the type of granulocytes that play an important role in detoxification.

A 30-year-old man with a history of no prior immunisation steps on a nail while walking barefoot in his courtyard and bleeds. Which immunisations should he undergo?

What is quarantine? Why is quarantine essential before introducing a plant species from another country?

Two groups (A and B) of bean plants of similar size and same leaf area were placed in identical conditions. Group A was exposed to light to wavelength of 400-450 nm, and Group B to light of wavelength of 500-550 nm. Compare the photosynthetic rate of the two groups giving reason.

Explain the relationship between biotic potential and environmental resistance.

Why are stimulants and hallucinogens categorized as psychotropic drugs? Give one example each of the two types mentioned.

How does oxidative phosphorylation differ from photophosphorylation? Explain.

Name the type of pollination taking place in coconut plant. List five characteristics of the flowers of coconut plant favouring this type of pollination.

List any three major categories of cancer. Explain briefly each category giving one example.

A 5-year-old child has complained of pain and swollen joints in his legs for the past one year. On physical examination, the doctor found bleeding gums, anaemia and emaciation.

Name the deficient vitamin and the corresponding deficiency disease the child is suffering from.

List any four functions of this vitamin.

OR

Why do pregnant women need to have higher levels of folic acid, iron and calcium in their diet?

What are tropical rain forests? Name any two dominant plant species of such forests in India. Why is soil in tropical deciduous forests richer in nutrients than in tropical rain forests?

What is senescence? How do free radicals make senescence faster?

Describe the special adaptations of xerophytes with respect to root system, stem and leaves.

List and explain the three ways in which carbon dioxide is transported by blood in the human body. Support the answer with a suitable diagram.

OR

Describe step by step what happens in the different phases of cardiac cycle in humans.

Name the two heart sounds and mention when they are respectively produced in the cardiac cycle.