Advertisements
Advertisements
प्रश्न
Which of the following would necessarily decrease the density of a population in a given habitat?
विकल्प
Natality > mortality
Immigration > emigration
Mortality and emigration
Natality and immigration
Advertisements
उत्तर
Mortality and emigration
Explanation:
A decrease in population density occurs when individuals die (mortality) or leave the habitat (emigration). Both factors reduce the number of individuals in that population. Therefore, mortality and emigration necessarily decrease population density in a given habitat.
APPEARS IN
संबंधित प्रश्न
Construct an age pyramid which reflects a stable growth status of human population.
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.
"Analysis of age-pyramids for human population can provide important inputs for long-term planning strategies." Explain.
List the attributes that populations but not individuals possess.
What is an age-pyramid?
What is reproductive fitness? Explain it with the help of an example.
Nutrient enrichment of water body result.
`"dN"/"dt" = "rN" (("K"- "N")/"K")` in logistic growth "K" represents:

Label the three tiers 1, 2, 3 given in the above age pyramid.
List any four characters that are employed in human population census.
Comment on the following figures: 1, 2 and 3:
A, B, C. D, G, P, Q, R, S are species

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.
Write the best method to measure the population density of a single Banyan tree in comparison to Partlzenium weeds in a forest by an ecologist. Explain and justify your answer.
What would be the best method to measure the total population density of a dense bacterial culture in a petridish and why?
