75. In gymnosperms and angiosperms, which one is the correct description?
(A) All gymnosperms are wind-pollinated.
(B) The fossil record shows that angiosperms evolved directly from the Gnetophytes.
(C) Horizontal gene transfer is restricted to prokaryotes and protists.
(D) The fossil record shows that pollen cones of conifers have become increasingly complex through their evolutionary history.
(E) Stamens and carpals are, in fact, modified sporangia-bearing leaves.

71. Which one is the correct description of salt and water balance in animal? (A) Sodium and potassium ions can easily diffuse through the lipid bilayer of plasma membranes. (B) Sweat has a higher salt concentration than the blood does in humans. (C) Animals that do not control internal water concentration also typically do not control the concentrations of ions like sodium and potassium. (D) Transport of salts against their concentration gradients is energetically expensive. (E) The filtrate that leaves the proximal convoluted tubule is much more concentrated than the blood in humans.

72. In species interaction, which one is the correct description of allelopathy? (A) Amensalism (B) The secretion of toxins into the environment by plant roots or leaves (C) Commensalism (D) Mutualism (E) The movement of genes from one species to another

73. In biodiversity, which one is the correct description of ecosystem diversity? (A) The amount of genetic variation that occurs within and between populations. (B) Only the amount of genetic variation that occurs between species. (C) Includes trophic diversity and process diversity. (D) Defines the species diversity and morphology of an ecosystem. (E) Refers to the structure and function within an ecosystem.

74. In the cross Aa Bb CC Dd Ee × Aa Bb Cc Dd EE, in which all genes undergo independent assortment, what proportion of offspring are expected to be homozygous dominant for all five genes? (A) (1/4) (B) (1/4)2 (C) (1/4)3 (D) (1/4)4 (E) 0

1. If the amount of enzyme in a reaction with an initial △G of -5 kcal/mole was doubled, what would the △G be? (A) -2.5 kcal/mole (B) -5 kcal/mole (C) -10 kcal/mole (D) +5 kcal/mole (E) +10 kcal/mole

2. Which is the most common route through which a protein is secreted from a eukaryotic cell? (A) plasmidplasma membranenuclear envelopesmooth endoplasmic reticulum (ER) (B) Golgi apparatuslysosomevesiclesplasma membrane (C) nuclear envelopevesiclesGolgi apparatusplasma membrane (D) rough endoplasmic reticulum Golgi apparatusvesicles plasma membrane (E) rough endoplasmic reticulumlysosomesvesiclescell membrane

3. Movement of integral membrane proteins between the apical and basolateral domains of an epithelial cell membrane is restricted by the presence of (A) lipid rafts. (B) basal lamina. (C) desmosomes. (D) tight junctions. (E) gap juncitions.

4. Which of the following statements about feedback inhibition in metabolic pathways is most correct? (A) The product of the pathway inhibits its own production by competitively binding to reactants in the metabolic pathway. (B) The product of the pathway inhibits its own production by noncompetitively binding to reactants in the metabolic pathway. (C) The product of the pathway inhibits its own production by competitively inhibiting the binding of a substrate to the active site of an enzyme within the metabolic pathway. (D) The product of the pathway inhibits its own production by noncompetitively inhibiting the binding of a substrate to the active site of an enzyme within the metabolic pathway. (E) All of the above

5. Which is NOT a microtubule-organizing center (MTOC)? (A) centrosome (B) basal body of cilia (C) mitotic spindle pole (D) kinetochore (E) all of the above

6. An mRNA sequence is 5’-AUG-GGC-ACU-CAU-ACU-UAA-3’, where AUG is the start codon and UAA is the stop codon. How many distinct aminoacyl-tRNA synthetases are required to translate the mRNA sequence? (A) 2 (B) 3 (C) 4 (D) 5 (E) 6