MODEL SUBJECTIVE QUESTION:
- What is population? Give its characteristics.
- Give history and background of population growth.
- Write note on seed dispersal.
- What is demography? Give its different aspects.
- Give applications of demography.
Differentiate between Monospecific and Polyspecific population.
Ans: Population of only one specie living in the same area then it is called Monospecific. Populations of different species living in the same area are called Polyspecific.
- What is population density? Give examples.
Ans: The number of individuals living in a unit area is called density. For example number of wheat plants in an acre etc. The unit of density varies in different species.
3: Differentiate between crude and ecological density?
Crude density is the number of individuals or biomass per unit of total area inhabited by the 5pecie. Ecological density is number of individuals or the biomass per unit of that area actually inhabited by the individual 0f the specie.
- What is Natality?
Ans: The rate at which the new individuals are added to a population in a unit time is called Natality.
6. What is meant by competition?
Ans: The individuals compete with each other for space and nutrients. Intraspecific competition occurs within same population. Individuals of the same specie compete with each other. It is more severe competition because all the individuals have same ecological niche.
- What is the role of seed in the dispersal of seeds?
. Ans: Most of the seeds are enclosed in the fruits like mango, guava and dates etc. The animals eat the flesh of fruit and throw away the seeds. Some seeds are not digested in the gut of animals. So they are thrown at different places with feces.
- Give three significance of dispersal of seeds.
Ans: Population of specie establish in another biome by dispersal of seeds. Seeds are importance source of primary and secondary succession. Seeds are food of many herbivores and omnivores. So they have role in food chain.
- What is seed bank? Give its significance.
Ans: The storage of seed in the soil is called seed bank. Seeds fall on the soil. They are buried in the soil. Some seeds germinate to form new plants. Some seed does not grow and remain dormant. ‘These seeds form the seed hank. Plant seeds can remain dormant for many years. This property of the seed has great significance for the survival of plants.
- Define demography.
Ans: The study of the vital statistics that affect population size is called demography.
- What art the effects of short generation time?
Ans: Short generation time: There is fast growth rate in populations with shorter generation time. Such populations have both high birth rate and death rate. Its example is annual plants.
- What are generation time and cohort?
Ans: The tables showing mortality summaries of a population is called life table. Cohorts are used to develop these tables. Cohort is a group of individuals of same age from birth till their death.
- What is clutch? Give its example.
Ans: The number of offspring or seeds produced at each reproductive cycle by a plant is called clutch size. For example, a plant produces 1000 seeds in its one season.