6. Mitochondria and chloroplasts have double membranes because
(A) their DNA is light-sensitive
(B) they need protection from lysosomes
(C) they are derived from eukaryotes
(D) the double membrane is required to maintain a hydrogen ion gradient
(E) they originated from endosymbiosis

2. How does the immune system produce so many different antibodies? (A) vertebrates inherit millions of different antibody genes (B) each antibody is the product of several different genes that are shuffled to produce new combinations (C) meiotic recombination and independent assortment lead to antibody variations (D) the immune system creates new B cells each time it is exposed to a new antigen (E) all of the above

3. Which of the following is true for both prokaiyotic and eukaryotic gene expression? (A) after transcription, a 3,poly-A tail and a 5，cap are added to mRNA (B) transcription of mRNA can begin before transcription is completed (C) RNA polymerase may recognize a promoter region upstream from the gene (D)mRN'A is synthesized in the 3direction (E) the mRNA transcript is the exact complement of the gene from which it was copied

4. During cellular respiration., pyruvate must be transported across (A) the cell membrane into intercellular space (B) both mitochondria membranes into the matrix (C) the outer mitochondria membrane into the stroma (D) the outer mitochondria membrane into the cytosol (E) the nuclear envelop into nucleus

5. "Which of the following statements about nonspecific defenses is false? (A) they include inflammatory responses (B) they include physical and chemical barriers (C) they must be primed by the presence of antigen (D) they may involve the formation of membrane attack complexes (E) marcophages and natural killer cells are participants in the process

7. A flower without sepals and petals is most likely pollinated by (A) bees (B) moths (C) bats (D) wind (E) insects

8. A species concept defined by phenotypic characters is referred as (A) biological species concept (B) ecological species concept (C) evolutionary species concept (D) morphological species concept (E) recognition species concept

9. _ are generally characterized by sporophyte with vascular system and without seed production in life cycle. (A) Mosses (B) Fems (C) Gymnosperms (D) Angiosperms (E) Algae

10. A structure in seed, which is equivalent to a leaf, is (A) seed coat (B) plumule (C) endosperm (D) coleoptile (E) cotyledon

11. A biodiversity hot spot is (A) a low species diversity in a small area (B) a low species diversity in a large area (C) a high species abundance in a large area (D) a high species diversity in a small area (E) a large species population size in a small area

12. Which of the following is an INCORRECT statement about plants? (A) they are sometimes referred to as embryophytes (B) they are all eukaryotic | (C) they are mostly terrestrial (D) they are polyphyletic (E) they have two dimorphic generations |