Organisms and Population - Chapter End Test | Class-12 Biology

 CLASS-XII    BIOLOGY     CHAPTER END TEST

CHAPTER-11: ORGANISMS AND POPULATION

Q.1	A population has more young individuals compared to the older individuals. What would be the status of the population after some years? a. It will decline b. It will stabilise c. It will increase d. It will first decline and then stabilise	1M
Q.2	Amensalism is an association between two species where: a. one species is harmed and other is benefitted b. one species is harmed and other is unaffected c. one species is benefitted and other is unaffected d. both the species are harmed.	1M
Q.3	Lichens are association of: a. bacteria and fungus b. alga and bacterium c. fungus and alga d. fungus and virus	1M
Q.4	According to Allen’s Rule, the mammals from colder climates have: a. shorter ears and longer limbs b. longer ears and shorter limbs c. longer ears and longer limbs d. shorter ears and shorter limbs	1M
Q.5	List four features which enable the Xeric plants to survive in the desert conditions.	2M
Q.6	Differentiate between regulators and conformers. Provide examples for each.	2M
Q.7	Write a short note on Parasitism.	3M
Q.8	Exponential growth and logistic growth are two types of growth of populations. Exponential growth is the increase in population size when plenty of resources are available. Logistic growth occurs when the increase in the size of the population is influenced by the resources in the environment. Most populations do not live under ideal conditions. Therefore, most do not grow exponentially. Certainly, no population can keep growing exponentially for very long. Many factors may limit growth. The carrying capacity (K) plays a very important role in determining the size of the population in any habitat. The largest population size that can be supported in an area without harming the environment.           a- K                     b- N                  c- C                 d- dN / dT dN/dt= Rn (K-N/K) is used for a- exponential growth b- logistic growth c- intermediate growth d- both logistic and exponential growth The exponential growth is not occurring in population due to       a- Competition for food and space  b- Unlimited resources  c- High reproduction capacity  d- All are correct Assertion: In dN/ dt= rN, N is the intrinsic rate of natural increase. Reason: N is a very important parameter to assess the impact of biotic and abiotic factors on population growth. Both assertion and reason are correct and the reason is the correct  explanation of assertion. Both assertion and reason are correct and reason is not a correct  explanation of assertion. c- Assertion is true but the reason is false d- Assertion is false but the reason is true.	4M
Q.9	Explain the logistic growth model in details.	5M