Are genes a segment of dna containing a set of instructions for making a protein ?

The given statement is True.

Gene can be described as the segment of DNA ( deoxyribonucleic acid), which codes for a particular protein. The protein thus formed, corresponds to a specific trait ( such as skin color, hair color, color of eye) of the individual organism.

They possess set of  instructions for making a protein in the form of nucleotide sequences. Gene undergo transcription to form mRNA ( messenger RNA), which is then converted into particular protein through translation.

Genes are inherited from parents by their offspring and in this way specific traits are inherited by offspring from their parents.

Thus, given statement in the question is correct.

answer: decrease

a limiting factor is the one which decrease the abundance, distribution and causes extinction of the population of species in a ecosystem. here, predators including hawks, owls and snakes are the limiting factor for the population of mexican free tailed bat.   although bats are nocturnal animals as they forge for food at night these predators also may remain active during night which can decrease the population of the mexican free-tailed bats. also, these bats eat only one type of insects that are moths. the food can also be a limiting factor as all 400 members are dependent upon same type of food needs that are moths. the decrease in the moth population can cause decrease in population size of the mexican free-tailed bats.

therefore, the scenarios will most likely to decrease the population size of the mexican free-tailed bats.