C. natural selection.
This is because in smaller populations the more that two separate groups of animals don’t interbreeding the father they become until speciation occurs where they cannot interbreed between the two groups.
Answer:
Ectotherms warm their bodies by absorbing heat from the surrounding environment, whereas Endotherms produce heat by their metabolic activities. • Ectotherms have large variations in normal body temperatures while endotherms maintain their body temperature in a fairly constant value
Explanation:
Answer:
In animals that give live birth, the fetal circulation is the circulatory system of a fetus. The term usually encompasses the entire fetoplacental circulation, which includes the umbilical cord and the blood vessels within the placenta that carry fetal blood.
2 seems like the best answer
Answer:A
Explanation:
A single nucleotide is made up of three components: a nitrogen-containing base, a five-carbon sugar, and a phosphate group. The nitrogenous base is either a purine or a pyrimidine. The five-carbon sugar is either a ribose (in RNA) or a deoxyribose (in DNA) molecule.