Please select the word from the list that best fits the definition A change in an organism’s surroundings that causes the organism to react.

the answer would be d

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.

cell/ tissue/ organ/ organ system/ body

the answer to the blank provided is “an autosomal gene that is required for the expression of genes on the x chromosome”.

testis-determining factor, abbreviated as td, which is more popularly known as sex-determining region y or sry protein, is a dna-binding protein or  gene-regulatory protein/transcription factor, encoded by the  sry gene. it is the gene responsible for the initiation of male gender determination in humans.