Answer the following question given this paragraph: All elements have an oxidation number of zero in their pure form. Q: In their pure form, all elements have an oxidation number of what? Choices: - 3 - 2 - 7 - zero A:
zero
Answer the following question given this paragraph: Q: A penguin must do what before molting? Choices: - hibernate - use muscle mass - mate - increase muscle mass A:
increase muscle mass
Q: Answer the following question given this paragraph: Why are so many amphibian species threatened by extinction, and why should you care? The second question is easy. Amphibians control pests, may be a source of new medicines, and help feed many other animals. The nature of amphibian skin may help explain why so many amphibian species are at risk. Their skin easily absorbs substances from the environment, such as pollutants in water or air. Therefore, they may suffer from poor environmental quality before other animals do. As such, they may provide an early-warning system of environmental damage. Q: Which part of the body of amphibians, easily absorbs substances from the environment? Choices: - liver - scales - Eyes - skin A:
A: skin
Question: Answer the following question given this paragraph: Did you ever wonder what happens to a candle when it burns? A candle burning is a chemical change in matter. In a chemical change, one type of matter changes into a different type of matter, with different chemical properties. Chemical changes occur because of chemical reactions. You can see more examples of chemical changes at this URL: http://www. youtube. com/watch?v=66kuhJkQCVM . Q: Chemical changes occur because of what? Choices: - liquid reactions - evaporation - toxic reactions - chemical reactions A:
Answer: chemical reactions
*Question*
Answer the following question given this paragraph: Under the direction of osteocytes, osteoblasts continuously build up bone, while osteoclasts continuously break down bone to maintain mineral homeostasis. Bone tissues include compact bone, spongy bone, bone marrow, and periosteum. Q: Osteoclasts break down bone to maintain mineral what? Choices: - density - fluctuations - polarity - homeostatis A:
**Answer**
homeostatis
(Question)
Answer the following question given this paragraph: The Neural Tube To begin, a sperm cell and an egg cell fuse to become a fertilized egg. The fertilized egg cell, or zygote, starts dividing to generate the cells that make up an entire organism. Sixteen days after fertilization, the developing embryo's cells belong to one of three germ layers that give rise to the different tissues in the body. The endoderm, or inner tissue, is responsible for generating the lining tissues of various spaces within the body, such as the mucosae of the digestive and respiratory systems. The mesoderm, or middle tissue, gives rise to most of the muscle and connective tissues. Finally the ectoderm, or outer tissue, develops into the integumentary system (the skin) and the nervous system. It is probably not difficult to see that the outer tissue of the embryo becomes the outer covering of the body. But how is it responsible for the nervous system? As the embryo develops, a portion of the ectoderm differentiates into a specialized region of neuroectoderm, which is the precursor for the tissue of the nervous system. Molecular signals induce cells in this region to differentiate into the neuroepithelium, forming a neural plate. The cells then begin to change shape, causing the tissue to buckle and fold inward (Figure 13.2). A neural groove forms, visible as a line along the dorsal surface of the embryo. The ridge-like edge on either side of the neural groove is referred as the neural fold. As the neural folds come together and converge, the underlying structure forms into a tube just beneath the ectoderm called the neural tube. Cells from the neural folds then separate from the ectoderm to form a cluster of cells referred to as the neural crest, which runs lateral to the neural tube. The neural crest migrates away from the nascent, or embryonic, central nervous system (CNS) that will form along the neural groove and develops into several parts of the peripheral nervous system (PNS), including the enteric nervous tissue. Many tissues that are not part of the nervous system also arise... Q: A sperm cell and an egg cell fuse to become what? Choices: - embryo - fetus - unfertilized egg - fertilized egg A:
(Answer)
fertilized egg