Fish lay a large number of eggs, few of which are fertilized and very few of which hatch into young ones. still fewer live to maturity and very few of these are fertile. which principles of evolution are represented in this example?

a. descent with modification and evolution
b. struggle for existence and survival of the fittest
c. adaptation and artificial selection

Option B, Struggle for existence and survival of the fittest

Explanation:

According to the Darwin’s theory of natural selection species which adapts themselves to the changing environmental condition in order to become efficient enough to survive and reproduce are termed as the “fittest” and thus he further stated that it is the “fittest” species which is able to survive.  

Option B also outlines the same concept and thus it is correct choice.

the abdomen (less formally called the belly, stomach, tummy or midriff) constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. the region occupied by the abdomen is termed the abdominal cavity. the stomach secretes acid and enzymes that digest food. ridges of muscle tissue called rugae line the stomach. the stomach muscles contract periodically, churning food to enhance digestion. the pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.

a researcher conducts an experiment on the secretion of a particular hormone in mice. scientists inject mice with a substance that stimulates the production of the hormone. the scientists then test the levels of hormones produced by the mice. the tool used to measure the hormones consistently detects the levels at 10 points lower than the actual hormone levels in the mice. this tool makes measurements, but the measurements aren't .

explanation:

no u