Answer No 1: True
Gene pool can be described as the number of genes which are present in a population of organisms which can interbreed. All the genetic information that is present in a population is the gene pool. As genes are made up of alleles, all the alleles which are present in a population will make up the gene pool.
Answer No 2: False
In genetics, a population can be described as the members of a species which can interbreed and produce fertile offsprings that are living in a certain area during a certain time period.
The option 2 is false because it does not specify area and time period in the definition.
Answer No 3: False
Over time, the genetic composition of a population will change. The organisms which will better adapted to survive to the environmental changes will survive and reproduce. The organisms which are not properly adapted might not be able to survive at all or they might become lesser in number. Hence, the genetic composition keeps changing depending on environmental changes.
Answer No 4: True
Population genetics can be described as a study of the genetic variations which occur in a certain population. It evaluates the gene frequency and how the gene frequency changes for a certain gene changes over time in a population.
Population genetics helps us to recognize the alleles which are better suited for an environment and which are present in a certain environment in abundance.
