Question

1111/2112 16) The African elephant (Loxodonta africana) has very sizable ears with large blood vessels flowing through them, as well as long columnar legs, while the wooly mammoth (Mammuthus primigenius), has very small ears and shorter thicker I than African elephants. Mammoths, however, weigh about twi account for these significant differences in ear and limb size between these two pachyderms? egs ice as much as the largest African elephants. What might A) The African elephant lives in hotter climates while the wooly mammoth lived in colder ones and these differences in limb and ear length reflect adaptation to these habitat differences. B) The African elephant probably has many more predators and needs these longer legs to escape and the larger ears to hear the danger coming C) These are probably differences due to coincidence and are not adaptations at all. D) There is not enough information to adequately answer this question. 17) The internal cells of gastropods are bathed by hemolymph because. A) their cells need to be able to extend pseudopodia. B) their cells need to prevent water movement via osmosis. C) their cells need to be protected from nitrogen gas in the atmosphere. D) their cells all need an aqueous medium for the exchange of nutrients, gases, and wastes 18) Caprimulgiforme birds (oilbirds, frogmouths, potoos, and owlet-nightjars) have been observed opening their mouths (gape) and exposing the wet surface of their mouths while performing gular (throat) fluttering. The rate of blood flow is also increased to the mouth as well. Why might do they do this? A) To allow themselves to loose excess heat via evaporation B) To allow themselves to loose excess heat via vasodilation C) To allow themselves to loose excess heat via vasoconstriction D) To allow themselves to loose excess heat via countercurrent exchange 19) Housecats require that the amino acid leucine be present in their diet (ie, it is essential). This means tht... A) only housecats use leucine B) Leucine is a necessary coenzyme for housecats. C) housecats are not able to synthesize leucine D) only certain foods contain leucine and must be fed to housecats. 20) A physician encounters a patient that fails to produce gastrin. As a result, the patient should.. A) have inactive parietal cells B) fail to produce HCI in his stomach C) be unable to digest proteins in the stomach. D) have all of the above as symptoms in this patient. 21) Positive feedback has occurred when A) an increase of blood sugar initiates the secretion of a hormone to store sugar as glycogen which then decreases when the sugar is brought to a proper level in the blood. B) a decrease in blood sugar initiates the secretion of a hormone that converts glycogen to glucose which then decreases when the blood sugar reaches the proper level C) a nursing infant's suckling increases the secretion of milk-releasing hormone in the mother which causes the production of milk to become greater and greater. D) an increase of calcium in the blood initiates the secretion of a hormone that stores calcium in bones which then decreases when the level in the blood reaches the proper level 22) Deer mice and reindeer differ in their energy budgets in that A) deer mice use a greater proportion of their metabolic energy to maintain body temperature B) deer mice use a greater proportion of their metabolic energy to seeking food. C) deer mice use a greater proportion of their metabolic energy for hibernating. D) deer mice use a greater amount of metabolic energy for growth.

Answer 1

16.

Correct: an organism adapt according to the conditions present in the living environment. This is tthe reason that African elephant has very sizable ears with the long columnar legs as they live in the hotter climate. Whereas, mammoths live in colder environment so they have more weight due to fat deposition and thicker legs.

Hence, the correct option is (A).

Incorrect: adaptation never occur coincidently as it is a systematic process for the benefit of organisms.

Hence, the options (B), (C) and (D) are incorrect.

17.

Correct: gastropods have hemolymph in place of blood present in the human. All the internal cells bath into the hemolymph as cell need an aqueous medium for the exchange f nutrients, gases and wastes.

Hence, the correct option is (D).

Incorrect: hemolymph is not necessary for the extension of pseudopodia. Free nitrogen gas does not directly affect the gastropods.

Hence, the options (A), (B) and (C) are incorrect.

20.

Correct: gastrin is a peptide hormone that is released by the parietal cells and help in stimulating the HCl production in stomach. So, if a patient fails to produce gastrin it may be due to inactive parietal cell. In such condition secretion of HClwill be impaired also digestion of protein will also be affected.

Hence, the correct option is (D).