Ratio between mortality and natality is called

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11.Organisms and Populations

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Ratio between mortality and natality is called

Population ratio

Vital index

Density coefficient

Census ratio

Solution

Vital index represents the ratio between natality (birth rate) and mortality (death rate). It determines the normal rate of growth of population and can be calculated by the following formula:

Vital index $=\frac{\text { Natality }}{\text { Mortality }} \times 100$

Standard 12

Biology

Ozone hole means

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The figure given below is a diagrammatic representation of response of organisms to abiotic factors. What $(a), (b), (c)$ represent respectively ?

$(a)$ $(b)$ $(c)$

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Ephemerals are xerophytes that are

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$I.$ Many xerophytic plants have thick cuticle on leaf epidermis and sunken stomata

$II.$ Some xerophytic plants have special photosynthetic pathway $(CAM)$ that enables their stomata close during day

$III.$ Opuntia has spines (modified leaves), photosynthetic phylloclade (stem)

$IV.$ All adaptations are genetically fixed in all organisms

Choose the combinations of correct option

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Loss of upper fertile layer of soil is known as

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Ratio between mortality and natality is called

Solution

Similar Questions

Ozone hole means

The figure given below is a diagrammatic representation of response of organisms to abiotic factors. What $(a), (b), (c)$ represent respectively ? $(a)$ $(b)$ $(c)$

Ephemerals are xerophytes that are

Loss of upper fertile layer of soil is known as

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The figure given below is a diagrammatic representation of response of organisms to abiotic factors. What $(a), (b), (c)$ represent respectively ?

$(a)$ $(b)$ $(c)$