Q19 of 30 Page 1

(a) State the role played by the following in the process of digestion.

(i) Enzyme trypsin


(ii) Enzyme lipase


(b) List two functions of finger like projections present in the small intestine.


(A)

Enzyme Trypsin: The pancreas secretes pancreatic juice which contains enzymes like trypsin for digesting proteins


Enzyme Lipase: The pancreas secretes pancreatic juice which contains enzymes like lipase for breaking down emulsified fats.


(B) The lining of the small intestine is covered with tiny finger-like projections called villi. The villi help the nutrients in food to be absorbed into the blood. The villi are carpet-like fingers inside the small intestine that help absorb nutrients.


More from this chapter

All 30 →
17

Complete and balance the following chemical equations:

(i) NaOH(aq) + Zn(s)→


(ii) CaCO3(s) + H2O(l) + CO2(g)→


(iii) HCl(aq) + H2O(l)→


OR


During electrolysis of brine, a gas ‘G’ is liberated at anode. When this gas ‘G’ is passed through slaked lime, a compound ‘C’ is formed, which is used for disinfecting drinking water.


(i) Write formula of ‘G’ and ‘C’.


(ii) State the chemical equation involved.


(iii) What is common name of compound ‘C’? Give its chemical name.


 18

(a) State with reason the consequence of decrease in number of carnivores in an ecosystem.

(b) In a food chain, state the trophic level at which the concentration of harmful chemicals is maximum. Why is it so?


OR


How is ozone layer formed ? State its importance to all life forms on earth ? Why the amount of ozone in the atmosphere dropped sharply in the 1980s ?


 20

A green stemmed rose plant denoted by GG and a brown stemmed rose plant denoted by gg are allowed to undergo a cross with each other.

(a) List your observation regarding


(i) Colour of stem in their F1 progeny


(ii) Percentage of brown stemmed plants in F2 progeny if F1 plants are self pollinated.


(iii) Ratio of GG and Gg in the F2 progeny.


(b) Based on the findings of this cross, what conclusion can be drawn ?


 21

(a) Classify the following as homologous or analogous pairs:

(i) Broccoli and cabbage


(ii) Ginger and Raddish


(iii) Fore limbs or birds and lizard


(iv) Wings of a bat and wings of a bird


(b) State the main feature that categorises a given pair of organs as homologous and analogous.