Answer:
gravitational force
Explanation:
Gravitational force is the force responsible for firmness while standing.
I would say overproduction. Not sure though. Hope this helps!
Answer:
Specie
Explanation:
They are a group that interbreed with each other, only, since they cannot produce fertile offspring with those of another species.
Answer:
Mutation, Gene flow/Migration/Immigration of gene and Recombination
Explanation:
For any species there are majorly three sources of genetic variations –
a) Mutation – This leads to change in the genetic code with in the DNA of an organism. Sometimes mutation does not produce any effect on the organism. Mutation can produce both positive and negative impact. Its effect is observed in long run as its rate is slow.
b) Recombination – When an organism undergoes sex, his/her genes recombine with the genes of mating partner. The rate of recombination is faster than the rate of mutation
c) Gene flow /Migration/Immigration of gene – In this gene travel from one set of population to the other. The frequency of gene in the mixed population lies between the original population gene frequency and the migrated or donor population gene frequency