HESI A2 Biology practice questions and answers well illustrated.

HESI A2 Biology practice questions and answers well illustrated. Which of the following is NOT a part of the body's chemical defense system against infection? a. Urine b. Hydrochloric acid c. Agranulocyte d. Lysozyme - correct answers.- Agranulocytes Agranulocytes are a type of white blood cell and therefore are not a part of the body's chemical defense system. Which of the following is considered an example of naturally acquired passive immunity? a. Attenuated (live) vaccine injection b. Breastfeeding c. Inactivated (killed) vaccine injection d. Exposure to a disease and subsequent immunity - correct answers.- breastfeeding Natural passive immunity occurs when live antibodies are transferred from one individual to another, such as when anti-bodies are transferred from a mother to her baby via breast milk. Worms lack which of the following? a. Eyes and brain b. Brain c. Eyes d. Nerve centers - correct answers.- eyes and brain Worms lack both eyes and a brain, but they do have nerve centers. Which organelle is responsible for generating ATP that is used for chemical energy? a. Mitochondria b. Vesicle c. Ribosome d. Golgi apparatus - correct answers.- mitochondria The mitochondrion is often referred to as the "power plant" of the cell, because it generates ATP, the cell's source of chemical energy. Which of the following is true with regard to eukaryotic and prokaryotic cells? a. Prokaryotic cells can contain lysosomes. b. Eukaryotic cells have mitochondria. c. Prokaryotic cells can contain lysosomes and eukaryotic cells have mitochondria. d. Prokaryotic cells have a nucleus. - correct answers.- Eukaryotic cells have mitochondria. One of the major differences between eukaryotic cells and prokaryotic cells is that eukaryotic cells contain organelles, such as mitochondria, whereas prokaryotic cells do not. Positive feedback is a mechanism used by the body that results in amplification or enhancement of a signal that has already been activated. An example of this would be: a. Slowing metabolism in response to starvation b. Shivering to increase temperature c. Blood vessels regulating blood pressure d. The release of oxytocin to increase contractions during childbirth - correct answers.- The release of oxytocin to increase contractions during childbirth Contractions in childbirth are considered a positive feedback loop because each contraction stimulates the brain to release more Oxytocin, which in turn stimulates more contractions. When placed in a hypotonic solution, a cell will do which of the following? a. Remain the same b. Disintegrate c. Swell d. Shrink - correct answers.- swell Water always moves from areas of higher concentration to lower concentration. A hypotonic solution contains less solutes and more water then the contents inside of the cell, so water will move from outside of the cell to inside, causing it to swell. Which is NOT an effect of photo-oxidation? a. Increase in tensile strength b. Discoloration c. Increase in brittleness d. Loss of surface smoothness - correct answers.- Increase in tensile strength Photo-oxidation occurs when UV light and ozone break down the surface of polymers. The result is the material becoming more brittle and discolored and less strong and smooth. The movement of a substance across a cell membrane from low to high concentration is known as what? a. Passive transport b. Diffusion c. Active transport d. Facilitated diffusion - correct answers.- Active transport Active transport is the movement of molecules against their concentration gradient, such as when moving from low to high concentration. During which stage of mitosis does the single cell split into two separate daughter cells? a. Telophase b. Cytokinesis c. Anaphase d. Prophase - correct answers.- Cytokinesis Cytokinesis occurs late in the process of mitosis and is marked by a single cell splitting into two daughter cells. Which of the following is NOT an example of an ecosystem? a. Marine b. Desert c. Ozone d. Grassland - correct answers.- Ozone An ecosystem is the interaction between living and non-living things in their environment. The ozone does not mean this definition as living and non-living things do not live and interact there. Decomposition occurs fastest in which type of environment? a. Moist, oxygenated b. Very dry, deoxygenated c. Very wet, deoxygenated d. Very dry, oxygenated - correct answers.- Moist, oxygenated The microbes involved in decomposition need oxygen and they function quicker at higher temperatures, which is why decomposition occurs at faster rates in moist, oxygenated areas. In a bird or a bee, the crop is responsible for what? a. Aiding in flying b. Maintaining balance when perched c. Storing food prior to digestion d. Helping to grind food - correct answers.- Storing food prior to digestion The crop is a muscular pouch that is part of the bird's digestive system. One partner benefitting while the other is harmed is what form of symbiotic relationship? a. Predation b. Commensalism c. Cannibalism d. Parasitism - correct answers.- Parasitism Parasitism is a non-mutual relationship where one organism benefits or feeds off another but does not kill them, such as with human head lice. The stigma of a flower serves what purpose? a. To bait pollinators b. To collect pollen c. To manufacture pollen d. To fertilize - correct answers.- To collect pollen