Q. 91. In the following food chain, if insects are removed, what will happen?Plant -> Insect -> Frog -> Snake
Population of frogs decreases
Population of snake increases
Population of frogs increases
Population of plants decreases
Answer:
(A) Population of frogs decreases
Explanation:
In this simple food chain, insects act as the primary food source for frogs. If insects are entirely removed, the frog population will starve and sharply decrease.
Q. 92. Which of the following statements about energy flow is INCORRECT?
The energy flow is unidirectional
Energy flow follows 10 percent law
The apex predators obtain maximum energy
Primary consumers obtain energy from plants
Answer:
(C) The apex predators obtain maximum energy
Explanation:
Due to the 10 percent law of energy transfer, 90% of energy is lost as heat at each trophic level. Therefore, apex predators at the top of the food chain receive the minimum (least) amount of energy, not the maximum.
Q. 93. Which of the following ecological pyramid is generally inverted?
Pyramid of energy
Pyramid of biomass in sea
Pyramid of numbers in grassland
Pyramid of biomass in a forest
Answer:
(B) Pyramid of biomass in sea
Explanation:
In aquatic (sea/ocean) ecosystems, the pyramid of biomass is typically inverted because the biomass of the primary producers (phytoplankton) is much smaller at any given moment than the biomass of the consumers (zooplankton, small fish, large fish) that rely on their rapid reproduction turnover.
Q. 94. Which of the following statements is INCORRECT about type III survivorship curve?
It indicates high mortality rates in early life.
It is most common in nature
Such a curve is typical of several plants, most insects, many fish
It indicates low mortality rates in early life
Answer:
(D) It indicates low mortality rates in early life
Explanation:
Type III survivorship curves are characterized by extremely high mortality rates for the young (early life), followed by a high survival rate for the few individuals that manage to reach adulthood (like fish, insects, and many plants). Therefore, stating that it indicates “low mortality rates in early life” is incorrect.
Q. 95. If N is the population density at time t, B is number of births, I is number of immigrants, D is number of deaths, E is the number of emigrants, then its density at time t+1 is
Answer:
(B)
Explanation:
The population density at the next time interval (t+1) is calculated by taking the current population (Nt), adding the incoming individuals (Births + Immigrants), and subtracting the outgoing individuals (Deaths + Emigrants).
