In a species, the weight of newborn ranges from 2 to 5 kg. 97% of the newborn with an average weight between 3 to 3.3 kg survive whereas 99% of the infants born with weights from 2 to 2.5 kg or 4.5 to 5 kg die. Which type of selection process is taking place?
Stabilizing Selection
Disruptive Selection
Cyclical Selection
Directional Selection
A.
Stabilizing Selection
The given data shows stabilising selection as most of the newborn having average weight between 3 to 3.3 kg survive and babies with less and more weight have low survival rate.
The number of individuals of the same species that have come into the habitat from elsewhere during the time period under consideration is known as
Emigration
Mortality
Natality
Immigration
Immigration
D.
Immigration
Immigration is the movement of individuals into a specific area.
Emigration is the act of leaving a place of residence or habitat wih the intent of living in another place.
Mortality is a measure of the number of deaths in a particular population.
Natality is the ratio of the number of births to the size of the population, i.e. birth rate.
An adaptation is a mutation, or genetic change, that helps an organism, such as a plant or animal, survive in its environment.
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.
(i) Curve a represents exponential growth which shows that there is ample food and space for the population. Resources are unlimited.
Curve b represents logistic growth and shows that there is limiting food and space for the population. The resources are limiting.
(ii) In the absence of predators, curve (a) would appropriately depict the prey population.
(iii) The dotted line represents the carrying capacity of the environment. The carrying capacity represents the size of population that the environment can hold by providing necessary resources. When a population reaches this line its population size is stabilized by various environmental factors.
Switch
