25. Which description below is correct about miRNA?
(A) They are originally short RNA sequences.
(B) An enzyme call Tricer trims the original form of miRNA.
(C)The trimmed product is double-stranded RNA.
(D) The trimmed products are stable thus could be used directly for next steps.
(E) If a miRNA sequence is completely complementary with an mRNA, the translation steps would be blocked and the mRNA would not degrade.

21. Gregor used parent generation seeds that have yellow-round phenotype (genotype YYRR) to cross with the parent generation seeds that have green-wrinkled phenotype (genotype yyrr). Then he crossed their F1 seeds to generate F2 seeds. Given the gene encodes color and the gene encodes shape of the seeds are independent assorted, what is the expected phenotypic ratio of the F2 seeds (Yellow-Round: Green-Round: Yellow-Wrinkled: Green-Wrinkled)? (A) 9:3:3:1 (B) 1:2:2:1 (C)2:3:3:2 (D) 4:1:1:4 (E) 1:4:4:1

22. Which description is incorrect about the viruses that infect bacteria? (A) They named phages. (B) They inject their genetic material in the bacterial cells. (C)They replicate within their host cells. (D) They could use either lytic cycles or lysogenic cycles to reproduce. (E) They all eventually break the host cells and kill the host cells.

23. We learned that gene expressed through transcription and translation. Which one below would involve in translation of a eukaryotic cell? (A) Ribosome (B) DNA template (C)RNA polymerase (D) Promoter (E) Spliceosome

24. In between of transcription and translation in a gene expression of an eukaryotic cell, there is a step called RNA processing. Which one below is INCORRECT? (A) It adds poly-A tail in this step. (B) It cuts out introns in this step. (C)The exons remain in the final product. (D) It adds a 5’-cap in this step. (E) The final product of this step is rRNA.

26. About the Human Genome Project (HGP), which one below is NOT true? (A) The results of HGP showed that most of the human genome does not consist of genes. (B) There are about three billion base pairs of nucleotides in a human genome. (C)There are about 21,000 genes in a human genome. (D) HGP began in 1990. (E) The first HGP was done by whole-genome shotgun method.

27. A Hardy-Weinberg equilibrial population would NOT show which property below? (A) The population would not have genetic drift. (B) The population would not have mutation (C)The allele frequencies do not change through time. (D) Natural selection would work in the gene pool of this population. (E) The individuals mate randomly within this population.

28. Which one below would lead to speciation? (A) The individuals in this species mate randomly. (B) The gene flow exists among the populations in a species. (C)The females cannot recognize males from sister species. (D) There is geographic barrier between two populations thus the exchanges of individuals were blocked. (E) The population size is small.

29. Which one is the correct sequence of the origins of organisms on earth? (A) Prokaryotes, multicellular eukaryotes, vascular plants, small invertebrates, single-celled eukaryotes. (B) Single-celled eukaryotes, prokaryotes, multicellular eukaryotes, vascular plants, small invertebrates. (C)Prokaryotes, single-celled eukaryotes, multicellular eukaryotes, small invertebrates, vascular plants. (D) Prokaryotes, single-celled eukaryotes, vascular plants, multicellular eukaryotes, small invertebrates. (E) Single-celled eukaryotes, prokaryotes, multicellular eukaryotes, vascular plants, small invertebrates.

30. Which one below is the most likely organism that evolved into chloroplast through the process of endosymbiosis? (A) Cyanobacterium (B) Green alga (C)E. coli (D) Red alga (E) Euglena

31. Where does meiosis take place in an angiosperm? (A) Seeds (B) Fruits (C)Ovule (D) Style (E) Stigma