NEET Biology Organisms and Populations MCQs Set 05

Answer: (b) Physiological ecology

Explanation:
1. At the organismic level ecology is concerned with physiology, so it is physiological ecology.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (c) Habitat

Explanation:
1. Regional and local variations within each biome lead to a wide variety of habitats.

Teacher's Note:
1. Altitude sickness occurs above about 3500 m; the body adapts by increasing RBC production, decreasing Hb binding affinity and increasing breathing rate.
2. Parasites show loss of sensory organs, adhesive organs, loss of digestive system and high reproductive potential.

Answer: (d) All above

Explanation:
1. Temperature, water, light and soil cause the variation in physical and chemical conditions of habitats.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (d) All the above

Explanation:
1. Temperature affects enzyme kinetics, basal metabolism and physiological functions.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (c) More than 100 ppt

Explanation:
1. Salinity in hypersaline lagoons is more than 100 ppt.

Teacher's Note:
1. Altitude sickness occurs above about 3500 m; the body adapts by increasing RBC production, decreasing Hb binding affinity and increasing breathing rate.
2. Parasites show loss of sensory organs, adhesive organs, loss of digestive system and high reproductive potential.

Answer: (a) Red algae

Explanation:
1. Red algae live in the deepest water since they absorb the blue-green light that penetrates deep.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (b) Diapause

Explanation:
1. Zooplankton of lakes and ponds overcome stressful conditions by diapause, a stage of suspended development.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (b) Conformers

Explanation:
1. The majority of plants and animals are conformers.

Teacher's Note:
1. Population interactions: mutualism (+/+), competition (-/-), predation and parasitism (+/-), commensalism (+/0), amensalism (-/0).
2. Gause's competitive exclusion principle, resource partitioning (MacArthur's warblers) and Paine's starfish (Pisaster) keystone study are favourite topics.

Answer: (a) Allen's rule

Explanation:
1. Shortening of ears and limbs in cold climates is Allen's rule.

Teacher's Note:
1. Altitude sickness occurs above about 3500 m; the body adapts by increasing RBC production, decreasing Hb binding affinity and increasing breathing rate.
2. Parasites show loss of sensory organs, adhesive organs, loss of digestive system and high reproductive potential.

Answer: (b) > 3500 m

Explanation:
1. Altitude sickness occurs above about 3500 m because of low atmospheric pressure and less oxygen.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (d) Both 1 and 2

Explanation:
1. Population ecology links ecology with population genetics and evolution.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (d) Both 1 and 3

Explanation:
1. Tiger census in India is based on pug marks and fecal pellets.

Teacher's Note:
1. Population interactions: mutualism (+/+), competition (-/-), predation and parasitism (+/-), commensalism (+/0), amensalism (-/0).
2. Gause's competitive exclusion principle, resource partitioning (MacArthur's warblers) and Paine's starfish (Pisaster) keystone study are favourite topics.

Answer: (b) a(iv), b(iii), c(ii), d(i)

Explanation:
1. Pacific salmon breeds once, most birds breed several times, oysters give many small offspring and mammals give few large offspring.

Teacher's Note:
1. Altitude sickness occurs above about 3500 m; the body adapts by increasing RBC production, decreasing Hb binding affinity and increasing breathing rate.
2. Parasites show loss of sensory organs, adhesive organs, loss of digestive system and high reproductive potential.

Answer: (c) a(iv), b(iii), c(i), d(ii)

Explanation:
1. +/+ is mutualism, -/- competition, +/- predation and -/0 amensalism.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (b) Princkly pear cactus

Explanation:
1. The prickly pear cactus caused the 'Australian havoc' after its introduction in Australia.

Teacher's Note:
1. Population interactions: mutualism (+/+), competition (-/-), predation and parasitism (+/-), commensalism (+/0), amensalism (-/0).
2. Gause's competitive exclusion principle, resource partitioning (MacArthur's warblers) and Paine's starfish (Pisaster) keystone study are favourite topics.

Answer: (b) Starfish pisater

Explanation:
1. Removal of the starfish Pisaster from a rocky intertidal community led to extinction of 10 invertebrate species within a year.

Teacher's Note:
1. Altitude sickness occurs above about 3500 m; the body adapts by increasing RBC production, decreasing Hb binding affinity and increasing breathing rate.
2. Parasites show loss of sensory organs, adhesive organs, loss of digestive system and high reproductive potential.

Answer: (a) Predation

Explanation:
1. Phytophagous (plant eating) insects show predation (herbivory).

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (c) Nectar

Explanation:
1. Nectar attracts pollinators and is not a defence; cardiac glycosides, strychnine and quinine are chemical defences.

Teacher's Note:
1. Population interactions: mutualism (+/+), competition (-/-), predation and parasitism (+/-), commensalism (+/0), amensalism (-/0).
2. Gause's competitive exclusion principle, resource partitioning (MacArthur's warblers) and Paine's starfish (Pisaster) keystone study are favourite topics.

Answer: (a) Difference in foraging activities

Explanation:
1. Warblers feeding in different parts of a tree avoided competition by differences in foraging activities.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (c) Hermit crab and sea anemone

Explanation:
1. The hermit crab and sea anemone relationship is mutualism, not commensalism.

Teacher's Note:
1. Altitude sickness occurs above about 3500 m; the body adapts by increasing RBC production, decreasing Hb binding affinity and increasing breathing rate.
2. Parasites show loss of sensory organs, adhesive organs, loss of digestive system and high reproductive potential.

Answer: (b) Clown fish only

Explanation:
1. In the sea anemone and clown fish relationship the clown fish is benefited and the anemone is unaffected, so it is commensalism.

Teacher's Note:
1. Organisms are conformers (most animals and plants), regulators (birds, mammals) or partial regulators; adaptations include migration, suspension (diapause, hibernation, aestivation) and behavioural responses.
2. Allen's rule: mammals in colder climates have shorter ears and limbs to reduce heat loss.

Answer: (b) Opuntia and Cactophagous moth

Explanation:
1. Opuntia and cactophagous moth is a biocontrol example, not coevolution; orchid-bee, Yucca-moth and fig-wasp are mutual adaptations.

Teacher's Note:
1. Population interactions: mutualism (+/+), competition (-/-), predation and parasitism (+/-), commensalism (+/0), amensalism (-/0).
2. Gause's competitive exclusion principle, resource partitioning (MacArthur's warblers) and Paine's starfish (Pisaster) keystone study are favourite topics.