An organism’s traits are its

1. An organism’s traits are its A. phenotype. genotype. DNA. D. all of the above.

2. An organism’s traits are its A. phenotype. • genotype. • DNA. D. all of the above.

3. What is the function of the proteins known as histones? • They divide sections of DNA into genes. • They determine where the DNA will unzip for replication. • They are the spools around which the DNA wraps. • They determine how the DNA will be divided into chromosomes.

4. What is the function of the proteins known as histones? • They divide sections of DNA into genes. • They determine where the DNA will unzip for replication. • They are the spools around which the DNA wraps. • They determine how the DNA will be divided into chromosomes.

5. A pair of matched chromosomes is called • haploid. • homologous. • diploid. • autosomal.

6. A pair of matched chromosomes is called • haploid. • homologous. • diploid. • autosomal. Explanation: Matched chromosomes are known as homologous chromosomes. Cells—not chromosomes—can be diploid or haploid. Autosomal chromosomes are the chromosomes that do not determine sex.

7. The “rungs” of a DNA ladder are made of • deoxyribose sugar. • phosphate. • genes. • nitrogenous bases.

8. The “rungs” of a DNA ladder are made of • deoxyribose sugar. • phosphate. • genes. • nitrogenous bases.

9. During DNA replication, • a new molecule of double-stranded DNA is created that is identical to the original. • one old strand is used to assemble one new strand. • the A nucleotide matches with the T and the C with the G. • all of the above occur.

10. During DNA replication, • a new molecule of double-stranded DNA is created that is identical to the original. • one old strand is used to assemble one new strand. • the A nucleotide matches with the T and the C with the G. • all of the above occur.

11. What is a key difference between RNA and DNA? • RNA lacks a sugar-phosphate backbone. • RNA is single stranded, and DNA is double stranded. • DNA uses the sugar ribose, but RNA uses the sugar deoxyribose. • In RNA, the bases are AGTC, and in DNA the bases are AGUC.

12. What is a key difference between RNA and DNA? • RNA lacks a sugar-phosphate backbone. • RNA is single stranded, and DNA is double stranded. • DNA uses the sugar ribose, but RNA uses the sugar deoxyribose. • In RNA, the bases are AGTC, and in DNA the bases are AGUC.

13. What process uses DNA as a template for building RNA? • Replication. • Translation. • Transcription. • Recombination.

14. What process uses DNA as a template for building RNA? • Replication. • Translation. • Transcription. • Recombination.

15. What occurs after the mRNA molecule has been transcribed? • A cap and a tail are added, and introns are removed. • Introns are removed, and exons are added. • Exons are removed, and a cap and tail are added. • A cap is added, and the tail is removed.

16. What occurs after the mRNA molecule has been transcribed? • A cap and a tail are added, and introns are removed. • Introns are removed, and exons are added. • Exons are removed, and a cap and tail are added. • A cap is added, and the tail is removed.

17. A codon • represents a protein. • contains introns and exons. • stands for one of the amino acids. • is all of the above.

18. A codon • represents a protein. • contains introns and exons. • stands for one of the amino acids. • is all of the above. Explanation: A codon is formed from a triplet of nucleotides and stands for one of the twenty amino acids that make up proteins.

19. During translation, the mRNA molecule is bound to a(n) • ribosome. • nucleotide. • codon. • anticodon.

20. During translation, the mRNA molecule is bound to a(n) • ribosome. • nucleotide. • codon. • anticodon.

21. A tRNA molecule A. carries all of the amino acids required to make the protein. B. includes a ribosome. C. transfers an amino acid to the protein being assembled. D. creates a stop codon.

22. A tRNA molecule A. carries all of the amino acids requiredto make the protein. B. includes a ribosome. C. transfers an amino acid to the protein being assembled. D. creates a stop codon.

23. During meiosis, • cell division creates haploid cells. • four cells are ultimately created from one. • crossing over occurs. • all of the above occur.

24. During meiosis, • cell division creates haploid cells. • four cells are ultimately created from one. • crossing over occurs. • all of the above occur.

25. What is the purpose of the crossing-over process in metaphase 1 of meiosis? • It ensures that the daughter cells are identical to the parent. • It completes the division of chromosomes into two new cells. • It moves the chromosomes to the poles of the cell. • It contributes to genetic variation among the sex cells.

26. What is the purpose of the crossing-over process in metaphase 1 of meiosis? • It ensures that the daughter cellsare identical to the parent. • It completes the division of chromosomes into two new cells. • It moves the chromosomes to the poles of the cell. • It contributes to genetic variation among the sex cells.

27. Before Mendel’s work was recognized, the dominant theory of inheritance was • blending inheritance. • the principle of segregation. • codominance. • polygenetics.

28. Before Mendel’s work was recognized, the dominant theory of inheritance was • blending inheritance. • the principle of segregation. • codominance. • polygenetics.

29. According to Mendel, when you cross a WW (round pea) plant with a ww (wrinkled pea) plant, the first-generation offspring will A. be a mix of wrinkled to round pea plants at a ratio of 3:1. B. be a mix of round to wrinkled pea plants at a ratio of 3:1. C. all be round pea plants. D. all be wrinkled pea plants.

30. According to Mendel, when you cross a WW (round pea) plant with a ww (wrinkled pea) plant, the first-generation offspring will A. be a mix of wrinkled to roundpea plants at a ratio of 3:1. B. be a mix of round to wrinkledpea plants at a ratio of 3:1. C. all be round pea plants. D. all be wrinkled pea plants.

31. An example of incomplete dominance is • a person’s blood type. • pink flowers produced by the mating of a white-flowered plant with a red-flowered plant. • a cat that is deaf and has white fur and blue eyes. • human height variance.

32. An example of incomplete dominance is • a person’s blood type. • pink flowers produced by the mating of a white-flowered plant with a red-flowered plant. • a cat that is deaf and has white fur and blue eyes. • human height variance.

33. Linked genes are • inherited together more often than expected. • on the same chromosome. • both A and B. • neither A nor B.

34. Linked genes are • inherited together more often than expected. • on the same chromosome. • both A and B. • neither A nor B.

35. The Human Genome Project demonstrated that • about 2% of the genome is junk DNA. • over 99.9% of base pairs are identical in all humans. • most genes are over 2 million bases long. • humans have about 100,000 genes.

36. The Human Genome Project demonstrated that • about 2% of the genome is junk DNA. • over 99.9% of base pairs are identical in all humans. • most genes are over 2 million bases long. • humans have about 100,000 genes.

37. Which type of mutation occurs when a nucleotide is inserted into a protein-coding sequence? • Nonsense mutation. • Stop mutation. • Point mutation. • Frameshift mutation.

38. Which type of mutation occurs when a nucleotide is inserted into a protein-coding sequence? • Nonsense mutation. • Stop mutation. • Point mutation. • Frameshift mutation.

39. Which of the following cancer-related genes act as recessive genes? • Tumor suppressor genes. • Oncogenes. • Both A and B. • Neither A nor B.

40. Which of the following cancer-related genes act as recessive genes? • Tumor suppressor genes. • Oncogenes. • Both A and B. • Neither A nor B.