13. Why is a guide RNA needed when using CRISPR-Cas9 for gene editing?
(A) to help Cas9 be transported into the nucleus
(B) to help Cas9 find the target DNA to cut
(C) to help repair the target DNA after it is cut
(D) to help make copies of the target DNA

9. Which statement regarding compound eyes is TRUE? (A) They have one light-focusing lens. (B) They are poor motion detectors. (C) They can provide excellent color vision. (D) They can perceive only visible light.

10. Which of the following biomes is characterized by mild, rainy winters and hot, dry summers? (A) Tropical forest (B) Temperate grassland (C)Savanna (D) Temperate seasonal forest (E) Mediterranean woodland and shrubland

11. A child dies following a series of chronic bacterial infections. At the autopsy, the physicians are startled to see that the child's white blood cells are loaded with vacuoles containing intact bacteria. Which explanation could account for this finding? (A) A defect in the Golgi apparatus prevented the cells from processing and excreting the bacteria. (B) A defect in the rough endoplasmic reticulum prevented the synthesis of the antibodies (defensive proteins) that would have inactivated the bacteria. (C) A defect in the cell walls of the white blood cells permitted bacteria to enter the cells. (D) A defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.

12. Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are (A) homologous chromosomes. (B) sister chromatids. (C) complementary chromosomes.

14. In mammals, the presence of four limbs is______， and hair is_______. (A) a shared derived character； a shared ancestral character that places mammals in the tetrapod clade (B) a shared ancestral character； a shared derived character unique to mammals (C) a homologous feature； an analogous feature (D) monophyletic； parsimonious

15. Which plant has a dominant sporophyte generation and a seed, but no fruit? (A)fern (B) pine tree (C) tulip (D) moss

16. Which statement about metabolism is FALSE? (A) The basal metabolic rate is the amount of energy an animal needs just to stay alive； it does not include the energy needed for activities. (B) Cells usually use carbohydrates and fats as fuel sources. (C) Humans store some extra energy in the forn of glycogen reserves in the pancreas and spleen. (D) The average basal metabolic rate is 1,300-1,500 kcal per day for females and 1,600-1,800 kcal per day for males.

17. In saltwater fish (A) the concentration of solutes in the internal fluids of saltwater fish is lower than that in the surrounding water. (B)the concentration of solutes in the internal fluids of saltwater fish is higher than that in th environment. (C) large amounts of diluted urine are produced. (D) body fluids have a solute concentration equal to their surroundings.

18. Suppose that the circular muscles in an earthworm have become selectively paralyzed such that they are not able to contract. How will this affect the earthworm's locomotion? (A) The earthworm will be able to elongate, but not get thicker. (B) The earthworm will be able to get thicker, but not elongate. (C) The earthworm will not be able to elongate or get thicker. (D) The earthworm will be able to crawl as normal.

19. In Utah of the USA, there is a clone of aspen trees that covers over 100 acres. Such clones can be considered as a single plant with many stems. It appears that the first stem of this clone originated over 80,000 years ago, even before there were humans in North America. What likely contributes most to the long-term survival (long life span) of aspens? (A) If parts of the organism (clone) are damaged, there are still other parts that can continue growing. (B) All parts of the clone carry the same genes. (C) A shared root system means that all stems receive the same nourishment. (D) Sexual reproduction can occur more frequently in clones.