What are endocrine disruptors and how do they affect wildlife populations? Provide two examples to support your answer
What will be an ideal response?
Answer: Endocrine disruptors are chemicals that interfere with the endocrine or hormone systems in animals and disrupt normal cell metabolism. Human sewage, which contains chemical pollutants, enters streams, rivers, or lakes, and can negatively affect wildlife populations. Researchers in England discovered that fish living close to the source of the sewage (outfall) had a higher percentage of intersex fish (fish that had both female and male characteristics). High levels of estrogens in the sewage feminized male fish and made them sterile.
Industrial chemicals, such as tributyltin in paint (which is used to keep barnacles from attaching to painted surfaces) are also endocrine disruptors. Tributyltin has been shown to cause a condition called imposex in species of mollusks. Imposex female snails develop a penis that blocks the opening of the oviduct. If most of the eggs cannot pass out via the oviduct, reproduction is hampered, and if there is total blockage, the snail dies. In both examples, the endocrine disruptors interfere with fertility and disrupt reproduction of the species.
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Ablation of the superior colliculus of the midbrain would induce partial deafness, and limit a person's ability to respond quickly to perceived sounds.
Answer the following statement true (T) or false (F)
The second neuron in an autonomic pathway is called a ________ neuron.
Fill in the blank(s) with the appropriate word(s).
Which of the following factors gives the myocardium its high resistance to fatigue?
a. the presence of intercalated discs b. a very large number of mitochondrion in the cytoplasm c. gap junctions d. the coronary circulation