The selection of traits at opposite ends of the spectrum is considered ...
A, disruptive selection

B, directional selection

C, stabilizing selection

Bisphenol a (often called bpa) is a chemical found in products that people use every day, from water bottles to food containers to children's toys. unfortunately, bpa leaches out of its many products and makes its way into our bodies. what are the health effects of bpa exposure? ongoing research is finding that elevated exposure to bpa can affect a wide variety of developmental and physiological processes, but one of the first studies of bpa's health effects came about because of a simple mistake in the lab. at a laboratory at case western reserve university in 1998, geneticist patricia hunt was making a routine check of her female lab mice. as she extracted and examined developing eggs from the ovaries, she began to wonder what had gone wrong. she noticed that many of the eggs showed problems with their chromosomes, and some had irregular amounts of genetic material, which can lead to miscarriages and birth defects in mammals. she learned that a lab assistant had mistakenly washed the plastic mouse cages and water bottles with a harsh soap, releasing bpa from the plastic. knowing that bpa is an endocrine disruptor, a chemical that can enter organisms and mimic hormones, hunt set out to discover whether it had adversely affected her mice.

Scenario #2 in 2001, a population of 2,500 poison dart frogs lived in the amazon rain forest. due to increased deforestation, the population dwindled to 25 frogs in 2019. new government regulations were enacted in 2022, successfully putting an end to the deforestation of the amazon rain forest. once deforestation was stopped, the poison dart frog population was able to recover. by 2050, the population reached 8,000 frogs, of that population, 20 are homozygous recessive for being spotted (ss genotype). q2- ? q- p- p2- 2pq-

Nephrons, the functional unit of kidneys, are responsible for formation of urine. the sentences describe situations that are the result of problems in the urine formation process. for the nephron shown below, match each situation to the step in the urine formation process where the problem lies.