4. What is unique about the sixth major extinction that many biologists believe is currently underway? [1 point] a) It began due to volcanic activity. b) It is caused by humans degrading and destroying habitats. c) It is caused by a massive asteroid impact. d) It is the result of natural climate changes 5. What are the possible causes of mass extinctions? (2 points) __ 6. What evidence do scientists use to study extinction events? [2 points] __ 7. What is the difference between a comet and an asteroid and why does it matter in terms of extinction events? [2 points] __

Which statement is true when you focus your eyes on a distant object? Ciliary muscles have contracted. The lens has rounded. There is now a shorter focal distance than if the object was close. There is greater light refraction than if the object was close.

Which of the following words means pertaining to a nucleus with many shapes or forms? mononuclear metamorphokaryotic polymorphonuclear polyphagonuclear

What role do the muscles and blood vessels play in the negative feedback loop of thermoregulation? effectors stimuli integration centers sensors

The function of dendrites is to A receive incoming signals from other neurons. B release neurotransmitters into the spatial junctions between neurons. C coordinate the activation of the parasympathetic and sympathetic nervous systems. D control pain through the release of opiate-like chemicals into the brain.

Which two vessels carry blood between the heart and the head? vena cava and aorta jugular vein and carotid artery femoral vein and carotid artery aorta and femoral vein

What is the name of the protein in red blood cells that binds to oxygen to carry it throughout the body? Glycophorin Immunoglobulin G Hemoglobin Insulin

What is the role of respiration in living organisms? It provides the energy needed by cells. It takes in the oxygen that organisms need. It removes the carbon dioxide that is a waste product. It transports materials like food and oxygen to the cells.

Rex is a dog who loves going for a ride on the back of his owner's tractor on the sheep farm. Every time his owner would walk towards the farm tractor Rex would wag his tail. Recently,his owner noticed that when he picks up his tractor keys, Rex's tail wags excitedly. a. UCS:? b. UCR:? c. NS: ? d. CS:? e. CR:?

Question 18 Iron binds to transferrin. is required by microorganisms. is necessary for the functioning of some enzymes. binds to lactoferrin All of the answer choices are correct. 1

Which of the following is not a function of connective tissues? Multiple Choice Fill spaces Provide support Bind structures together Body movement