FREE NEET Biology Practice MCQ Test: Organisms And Populations Exercise 2 Questions Answers With Detailed Explanations [PDF]

Answer: (b)

Intrinsic rate of natural increase can be defined as the number of births minus the number of deaths. Thus, a population having highest intrinsic rate will increase fastest among all of the given populations.

Answer: (a)

Natality and immigration positively contribute to the population growth while mortality and emigration are negative factors. In the given question,

The net increase in population is
natality + immigration = 250 + 20 = 270
The net decrease in population is
mortality + emigration = 240 + 30 = 270
Thus, net increase in population = 270 – 270 = 0

Answer: (c)

Answer: (a)

Answer: (c)

Assertion is true, but Reason is false. It can be corrected as

Excessive leaching (washing away by water) of the soil depletes its organic content.

Answer: (d)

They are correct as Although, the total number is the most appropriate measure of population density, in some cases, it is difficult to determine. In a forest area, suppose there are 200 Parthenium plants but only a single huge banyan tree with a large canopy is present. Thus, stating that the population density of banyan is low relative to that of Parthenium amount to under estimating the great role of the banyan in that forest community. In such cases, the per cent cover or biomass is a more meaningful measure of the population size. If the population is huge and counting is impossible or very time consuming, the total number is not easily measured, e.g. for a dense laboratory culture of bacteria in a petri dish only the biomass can be used as a measure of its population density.

Answer: (d)

Maximum growth rate occurs in exponential or acceleration or log phase. The point at which the exponential growth begins to slow down is known as inflexion point.

Answer: (d)

Such a population exhibits an equilibrial life history.

Answer: (c)

Answer: (a)

Answer: (d)

Both the populations are herbivorous, thus they cannot affect each other. If the food sources for these populations A and B have decreased, then both the populations A and B would have declined. If population A have produced more offspring then the graph A should have increased. Based on the graph, population B is more successful in competing with population A, that is why number of organisms in population B increased while that in population A decreased, as they get access to limited resources.

Answer: (d)

Protoplasm is the material comprising the living content of a cell. It consists of 90% water along with the minerals, sugars, amino acids, proteins, enzymes, etc. The translocation of nutrients inside the body occurs via blood which also majorly consists of water. In an environment with excessive heat, water loss in the form of sweating and transpiration keeps the body cool. Thus, water maintains the body temperature.

Answer: (b)

Monocarpic plants are those plants which flower once in their life and die. Thus, banana is a monocarpic plant as it reproduces sexually once in its life and then dies.

Answer: (b)

Answer: (b)

Answer: (d)

Answer: (b)

Among the given options, biome is the highest level of biological hierarchy. It is a large regional unit delimited by a specific climatic zone having a particular major vegetation zone associated with fauna, e.g. ocean, tropical rainforest.

Answer: (c)

Logistic population growth is expressed by following equation:
${dN}/{dt} = r N({K - N}/)$
Where, N = population density at time t
r = intrinsic rate of natural increase
K = carrying capacity

Answer: (a)

Answer: (d)