Q15 of 36 Page 1

Assertion: Food chain is responsible for the entry of harmful chemicals in our bodies.

Reason: The length and complexity of food chains vary greatly.


a) Both A and R are true, and R is correct explanation of the assertion.


b) Both A and R are true, but R is not the correct explanation of the assertion.


c) A is true, but R is false.


d) A is false, but R is true.


OR


Assertion: Greater number of individuals are present in lower trophic levels.


Reason: The flow of energy is unidirectional.


a) Both A and R are true, and R is correct explanation of the assertion.


b) Both A and R are true, but R is not the correct explanation of the assertion.


c) A is true, but R is false.


d) A is false, but R is true.


b) Both Assertion & Reasoning are correct, Reason is not correct explanation of Assertion


Through Biomagnification, harmful chemicals that are not metabolised by our body pass into the food chain, irrespective of the length and complexity of the food chain, which may vary in nature.


OR


b) Both Assertion & Reasoning are correct, Reason is not correct explanation of Assertion


Greater numbers of individuals are present in the lower trophic levels because more free energy is available at the lower levels and as we climb up the trophic levels, with each step, there is a decrease of 10% of free energy. As the free energy reduces, lesser organisms are able to survive on the available energy. This assertion is not supported by the statement that the flow of energy.


More from this chapter

All 36 →
13

State the role of pancreas in digestion of food.

 14

For question numbers 14, 15 and 16, two statements are given- one labeled Assertion (A) and the other labeled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:

Assertion: After white washing the walls, a shiny white finish on walls is obtained after two to three days.


Reason: Calcium Oxide reacts with Carbon dioxide to form Calcium Hydrogen Carbonate which gives shiny white finish.


a) Both A and R are true, and R is correct explanation of the assertion.


b) Both A and R are true, but R is not the correct explanation of the assertion.


c) A is true, but R is false.


d) A is false, but R is true.


 16

Assertion: A geneticist crossed a pea plant having violet flowers with a pea plant with white flowers, he got all violet flowers in the first generation.

Reason: White colour gene is not passed on to the next generation.


a) Both A and R are true, and R is correct explanation of the assertion.


b) Both A and R are true, but R is not the correct explanation of the assertion.


c) A is true, but R is false.


d) A is false, but R is true.


 17

Read the following and answer any four questions from 17 (i) to 17 (v)

All living cells require energy for various activities. This energy is available by the breakdown of simple carbohydrates either using oxygen or without using oxygen


(i) Energy in the case of higher plants and animals is obtained by


a) Breathing


b) Tissue respiration


c) Organ respiration


d) Digestion of food


(ii) The graph below represents the blood lactic acid concentration of an athlete during a race of 400 m and shows a peak at point D.



Lactic acid production has occurred in the athlete while running in the 400 m race. Which of the following processes explains this event?


a) Aerobic respiration


b) Anaerobic respiration


c) Fermentation


d) Breathing


(iii) Study the graph below that represents the amount of energy supplied with respect to the time while an athlete is running at full speed.




(iv) The characteristic processes observed in anaerobic respiration are


i) presence of oxygen


ii) release of carbon dioxide


iii) release of energy


iv) release of lactic acid


a) i) ,ii) only


b) i), ii), iii) only


c) ii), iii), iv) only


d) iv) only


(v) Study the table below and select the row that has the incorrect information