Benthic organisms are affected most by
Options
(a) Water-holding capacity of soil (b) Light reaching the forest floor (c) Surface turbulence of water (d) Sediment characteristics of aquatic ecosystems
Correct Answer:
Sediment characteristics […]
The age pyramid with broad base indicates
Options
(a) High percentage of young individuals (b) High percentage of old individuals (c) Low percentage of young individuals (d) A stable population
Correct Answer:
High […]
What is true about the isolated small tribal populations?
Options
(a) There is a decline in population as boys marry girls only from their own tribe (b) Hereditary diseases like colour blindness do […]
Two plants can be conclusively said to belong to the same species if they
Options
(a) have more than 90 per cent similar genes (b) look similar and possess identical secondary metabolites (c) […]
Which one of the following statements is correct for secondary succession ?
Options
(a) It begins on a bare rock (b) It occurs on a deforested site (c) It follows primary succession (d) […]
The population of an insect species shows an explosive increase in numbers during rainy season followed by its disappearance at the end of the season. What does this show?
Options
(a) The food […]
In the case of peppered moth (Biston betularia) the black – coloured form became dominant over the light- coloured form in England during industrial revolution. This is an example of:
Options
(a) appearance […]
A biologist studied the population of rats in a barn. He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is :
Options […]
The correct sequence of plants in a hydrosere is:
Options
(a) Volvox → Hydrilla → Pistia →Scirpus Lantana → Oak (b) Pistia →Volvox →Scirpus →Hydrilla → Oak →Lantana (c) Oak→Lantana →Volvox →Hydrilla → […]
Pheretima and its close relatives derive nourishment from :
Options
(a) sugarcane roots (b) decaying fallen leaves and soil organic matter (c) soil insects (d) small pieces of fresh fallen leaves of maize, […]
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