5. What is the enzymatic function of restriction enzymes?
(A) to add new nucleotides to the growing strand of DNA
(B) to join nucleotides during replication
(C) to join nucleotides during transcription
(D) to cleave nucleic acids at specific sites
(E) to repair breaks in sugar-phosphate backbones

1. Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely cold? (A) by increasing the percentage of unsaturated phospholipids in the membrane (B) by increasing the percentage of cholesterol molecules in the membrane (C) by decreasing the number of hydrophobic proteins in the membrane (D) by decreasing the number of cytoskeleton proteins (E) by using active transport

2. To repair a thymine dimmer by nucleotide excision repair, in which order do the necessary enzymes act? (A) exonuclease, DNA polymerase III, RNA primase (B) helicase, DNA polymerase I, DNA ligase (C) DNA ligase, nuclease, helicase (D) DNA polymerase I, DNA polymerase III, DNA Tigase (E) endonuclease, DNA polymerase I, DNA ligase

3. In eukaryotes there are several different types of RNA polymerase. Which type is involved in transcription of mRNA for a globin protein? (A) RNA polymerase I (B) RNA polymerase II (C) RNA polymerase III (D) ligase (E) primase

4. Genomic imprinting, DNA methylation, and histone acetylation are all examples of _________.(A) genetic mutation (B) chromosomal rearrangements (C) epigenetic phenomena (D) karyotypes (E) translocation

6. Which of the following are sugar-transporting cells in angiosperms? (A) sieve-tube elements (B) parenchyma cells (D) sclerenchyma cells (E) tracheids and vessel elements (C) collenchyma cells

7. What is the role of proton pumps in root hair cells? (A) establish ATP gradients (B) acquire minerals from the soil(C) pressurize xylem transport (D) eliminate excess electrons (E) A and Donly

8. Nitrogen fixation is a process that _______.(A) recycles nitrogen compounds from dead and decaying materials (B) converts ammonia to nitrate (C) converts nitrogen gas into ammonia (D) releases nitrate from amino acids (E) B and C

9. Where does meiosis occur in flowering plants? (A) megasporocyte (B) microsporocyte (C) endosperm (D) pollen tube (E) megasporocyte and microsporocyte

10. Plants growing in a partially dark environment will grow toward light in a response called phototropism. Choose the incorrect statement regarding phototropism. (A) It is caused by a chemical signal. (B) One chemical involved is auxin. (C) Auxin causes a growth increase on one side of the stem. (D) Auxin causes a decrease in growth on the side of the stem exposed to light. (E) Removing the apical meristem prevents phototropism.

11. Why is the velocity of blood flow the lowest in capillaries? (A) The capillary walls are too thin to maintain the velocity of blood flow in capillaries. (B) Capillaries are far from the heart, and blood flow slows as the distance from the heart increases. (C) The diastolic blood pressure is too low to deliver blood to the capillaries at a high flow rate. (D) The total surface area of the capillaries is larger than the total surface area of the arterioles. (E) The systemic capillaries are supplied by the left ventricle, which has a lower cardiac output than the right ventricle.