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प्रश्न
An individual and a population has certain characteristics. Name these attributes with definitions.
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उत्तर
A population has certain attributes that an individual organism does not. An individual may have births and deaths, but a population has birth rates and death rates. In a population, these rates refer to per capita births and deaths, respectively. The rates, hence, expressed as change in numbers (increase or decrease) with respect to members of the population.
- Another attribute characteristic of a population is sex ratio. An individual is either a male or a female but a population has a sex ratio (e.g., 60 per cent of the population are females and 40 per cent males).
- A population at any given time is composed of individuals of different ages. If the age distribution (per cent individuals of a given age or age group) is plotted for the population, the resulting structure is called an age pyramid. For the human population, the age pyramids generally show the age distribution of males and females in a combined diagram. The shape of the pyramids reflects the growth status of the population.
- Whether it is growing
- Stable
- Declining
Representation of age pyramids for human population
APPEARS IN
संबंधित प्रश्न
(a) Name the two growth models that represent population growth and draw the respective growth curves they represent.
(b) State the basics for the difference in the shape of these curves
(c) Which one of the curves represents the human population growth at present? Do you think such a curve is sustainable? Give reason in support of your answer.
Study the graph given below and answer the questions that follow :
(i) Write the status of food and space in the curves (a) and (b).
(ii) In the absence of predators, which one of the two curves would appropriately depict the prey population?
(iii) Time has been shown on X-axis and there is a parallel dotted line above it. Give the significance of this dotted line
Represent diagrammatically three kinds of age-pyramids for human populations.
How does an age pyramid for human population at given point of time helps the policy-makers in planning for future.
List the attributes that populations but not individuals possess.
If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?
What is an age-pyramid?
Animals that can move from fresh water to sea called as ________.
Measures of ‘Central tendency’ refer to:
`"dN"/"dt" = "rN" (("K"- "N")/"K")` in logistic growth "K" represents:
Age distribution in a population can influence
Which one of the following organisms reproduces sexually only once in its lifetime?
The density of a population in a habitat per unit area is measured in different units. Write the unit of measurement against the following:
Banyan
Label the three tiers 1, 2, 3 given in the above age pyramid.
What type of population growth is represented by the above age pyramid?
List any four characters that are employed in human population census.
Given below is the Age Pyramid of the population in one of the states in India as per 2011 census. It depicts the male population on the left-hand side, female population on the right-hand side, newborns towards the base and gradually increasing age groups as we move from base to the top, with the oldest population at the top. Study this pyramid and comment upon the appropriateness of the Assertion and the Reason.
Percentage to the total population
Assertion: It is a stable population.
Reason: The pre-reproductive and reproductive individuals are almost in equal numbers and the post-reproductive individuals are relatively fewer.
Identify the type of pyramid given above. Write the identifying feature on the basis of which you identified it.
The number of lily plants in a pond was found to be 50. After one year, the number. increased to 65. Calculate the natality of lily plants.
