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Organisms and Populations

Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.

Organisms and Environment

Subtopic

Organisms and Environment under Organisms and Populations for Grade 12 CBSE.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    In many lakes and ponds, various species of zooplankton respond to unfavorable environmental conditions by entering a specific stage of suspended development. Identify the term for this stage as represented by 'X' in the process below.

    A.

    Aestivation

    B.

    Hibernation

    C.

    Diapause

    D.

    Migration

  2. 2.

    In addition to temperature and light, which abiotic factor is most critical for the survival of organisms?

    A.

    Soil

    B.

    Water

    C.

    Air

    D.

    Pressure

  3. 3.

    What is the primary source of energy for almost all ecosystems on Earth?

    A.

    Soil

    B.

    Water

    C.

    Sun

    D.

    Wind

Download the worksheet for Organisms and Populations - Organisms and Environment to practice offline. It includes additional chapter-level practice questions.

Populations: Growth, Attributes and Age Pyramids

Subtopic

Populations: Growth, Attributes and Age Pyramids under Organisms and Populations for Grade 12 CBSE.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    Which of the following is true for a population with an expanding age pyramid?

    A.

    Birth rate is higher than death rate

    B.

    Death rate is higher than birth rate

    C.

    Birth rate and death rate are equal

    D.

    The population is decreasing

  2. 2.

    The total number of individuals of a species per unit area or volume at a given time is called:

    A.

    Population size

    B.

    Population density

    C.

    Population distribution

    D.

    Vital index

  3. 3.

    Which phase is NOT part of the logistic growth curve?

    A.

    Lag phase

    B.

    Phase of acceleration

    C.

    Phase of deceleration

    D.

    Infinite growth phase

Download the worksheet for Organisms and Populations - Populations: Growth, Attributes and Age Pyramids to practice offline. It includes additional chapter-level practice questions.

Population Interactions (Mutualism, Competition, Predation, Parasitism)

Subtopic

Population Interactions (Mutualism, Competition, Predation, Parasitism) under Organisms and Populations for Grade 12 CBSE.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    The association where one species is harmed ()(-) and the other is unaffected (0)(0) is known as:

    A.

    Commensalism

    B.

    Amensalism

    C.

    Mutualism

    D.

    Competition

  2. 2.

    Many insects and frogs are cryptically colored to:

    A.

    Attract a mate

    B.

    Avoid being detected by predators

    C.

    Absorb more sunlight

    D.

    Thermoregulate

  3. 3.

    Which of the following interactions results in the death of the host organism eventually (though not always immediately)?

    A.

    Mutualism

    B.

    Commensalism

    C.

    Parasitism

    D.

    Competition

Download the worksheet for Organisms and Populations - Population Interactions (Mutualism, Competition, Predation, Parasitism) to practice offline. It includes additional chapter-level practice questions.