*Question*
Q: What is the term for traits that show wide variation, such as height, skin color, and eye color? Read this paragraph and choose the correct option from the provided answers: Usually, traits are polygenic when there is wide variation in the trait. For example, humans can be many different sizes. Height is a polygenic trait, controlled by at least three genes with six alleles. If you are dominant for all of the alleles for height, then you will be very tall. There is also a wide range of skin color across people. Skin color is also a polygenic trait, as are hair and eye color. Choices: - maladaptive traits - inherited traits - recessive traits - polygenic traits A:
**Answer**
polygenic traits

*Question*
Q: In the lungs, bicarbonate is transported back into the red blood cells in exchange for what? Read this paragraph and choose the correct option from the provided answers: 39.4 Transport of Gases in Human Bodily Fluids Hemoglobin is a protein found in red blood cells that is comprised of two alpha and two beta subunits that surround an iron-containing heme group. Oxygen readily binds this heme group. The ability of oxygen to bind increases as more oxygen molecules are bound to heme. Disease states and altered conditions in the body can affect the binding ability of oxygen, and increase or decrease its ability to dissociate from hemoglobin. Carbon dioxide can be transported through the blood via three methods. It is dissolved directly in the blood, bound to plasma proteins or hemoglobin, or converted into bicarbonate. The majority of carbon dioxide is transported as part of the bicarbonate system. Carbon dioxide diffuses into red blood cells. Inside, carbonic anhydrase converts carbon dioxide into + + carbonic acid (H2CO3), which is subsequently hydrolyzed into bicarbonate (HCO 3 ) and H . The H ion binds to hemoglobin in red blood cells, and bicarbonate is transported out of the red blood cells in exchange for a chloride ion. This is called the chloride shift. Bicarbonate leaves the red blood cells and enters the blood plasma. In the lungs, bicarbonate is transported back into the red blood cells in exchange for chloride. The H+ dissociates from hemoglobin and combines with bicarbonate to form carbonic acid with the help of carbonic anhydrase, which further catalyzes the reaction to convert carbonic acid back into carbon dioxide and water. The carbon dioxide is then expelled from the lungs. Choices: - phosphate - glucose - oxygen - chloride A:
**Answer**
chloride

*Question*
Q: Some fish will be over-fished to the point that their species ceases to exist, which is also known as what? Read this paragraph and choose the correct option from the provided answers: will inevitably make it more difficult and costly to grow food. The world's growing human population faces significant challenges in the increasing costs and other difficulties associated with producing food. Wild Food Sources In addition to growing crops and raising food animals, humans obtain food resources from wild populations, primarily wild fish populations. For about one billion people, aquatic resources provide the main source of animal protein. But since 1990, production from global fisheries has declined. Despite considerable effort, few fisheries on Earth are managed sustainability. Fishery extinctions rarely lead to complete extinction of the harvested species, but rather to a radical restructuring of the marine ecosystem in which a dominant species is so over-harvested that it becomes a minor player, ecologically. In addition to humans losing the food source, these alterations affect many other species in ways that are difficult or impossible to predict. The collapse of fisheries has dramatic and long-lasting effects on local human populations that work in the fishery. In addition, the loss of an inexpensive protein source to populations that cannot afford to replace it will increase the cost of living and limit societies in other ways. In general, the fish taken from fisheries have shifted to smaller species and the larger species are overfished. The ultimate outcome could clearly be the loss of aquatic systems as food sources. Choices: - endangered - accumulation - abundance - extinction A:
**Answer**
extinction

*Question*
Q: Newly duplicated chromosomes are divided into two daughter nuclei during what stage? Read this paragraph and choose the correct option from the provided answers: During mitosis, the newly duplicated chromosomes are divided into two daughter nuclei. Choices: - meiosis - symphysis - prophase - mitosis A:
**Answer**
mitosis