61. In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the frequency of the allele a is 0.3. What is the percentage of the population that is homozygous for this allele?
(A) 0.09
(B) 0.49
(C) 0.9
(D) 9.0
(E) 49.0

57. Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large and complex lipids. Which cellular organelle must be involved in this condition? (A) the endoplasmic reticulum (B) the Golgi apparatus (C) the lysosome (D) mitochondria (E) membrane-bound ribosomes

58. Which of the following is an example of Batesian mimicry? (A) an insect that resembles a twig (B) a butterfly that resembles a leaf (C) a nonvenomous snake that looks like a venomous snake (D) a fawn with fur coloring that camouflages it in the forest environment (E) a snapping turtle that uses its tongue to mimic a worm, thus attracting fish

59. A patient who has a parasitic worm infection and another patient responding to an allergen such as ragweed pollen have which of the following in common? (A) an increase in cytotoxic T cell number (B) suffering from anaphylactic shock (C) risking development of an autoimmune disease (D) suffering from a decreased level of innate immunity (E) an increase in the levels of IgE

60. Endothermy is _____. (A) a characteristic of most animals found in tropical zones (B) a characteristic of animals that have a fairly constant body temperature (C) a term equivalent to cold-blooded (D) a characteristic of mammals but not of birds (E) seen only in insects and in certain predatory fishes

62. By karyotype analysis, a woman is found to have 47 chromosomes, including one extra X chromosome. What kind of phenotype for her is expected? (A) normal female (B) sterile female (C) enlarged genital structures (D) albino (E) color blindness

63. Which one of following statements is FALSE? (A) In a species that has a chromosome number of 2n = 16, each cell has eight homologous pairs. (B) An error in either egg or sperm meiotic anaphase might result in a human zygote with 45 chromosomes. (C) Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote. (D) At sexual maturity, ovaries and testes produce diploid gametes by meiosis. (E) If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have 63 chromosomes in 21 sets of 3.

64. Which of the following structures is primarily involved in the detoxification of many poisons and drugs in liver and therefore abundant in liver cells? (A) Golgi apparatus (B) smooth ER (C) chemical (D) rough ER (E) transport vesicles

65. In systematics and phylogeny, which one is the correct description? (A) A phylogenetic tree is actually a theory that depicts the evolutionary relationships among species. (B) A paraphyletic group contains groups of species with different common ancestors. (C) Morphology is a term that refers to similarities among various species that occur because the species are derived from a common ancestor. (D) Where a branching point in a phylogenetic tree is called a clade. (E) A phylotenetic tree is then being used as a cladogram.

66. In animal circulatory systems, which one is the correct description? (A) Hemophilia results from a deficiency in platelets. (B) The meshwork that forms the fabric of a blood clot mostly consists of fibrinogen. (C) Reduced levels of hemoglobin in the blood result in the condition of anemia. (D) During cellular maturation, mammalian erythrocytes lose their plasma membrane. (E) The primary function served by erythrocytes is defense against pathogens.

67. In animal digestion and absorption, which one is the correct description? (A) The small intestine releases the hormone secretin in response to acid. (B) Fats packaged in chylomicrons pass directly from epithelial cells to the bloodstream. (C) In the stomach, proteins are cleaved into amino acids by aminopeptidases. (D) All sugars are absorbed via secondary active transport. (E) In omnivores, including humans, the cecum is an important organ for digestion of cellulose.