Biology 2012 Fall Semester Exam Review
1. Use the codon chart to determine what mRNA codons would produce the following sequence of
amino acids.
Cysteine-tryptophan-glycine-alanine
UGU UGG GGU GCU
2. Use the codon chart to determine what amino acids would be produced by the following sequence of
mRNA codons.
AUG-UUA-AAU
MET – LEU – ASP
3. During what part of meiosis do chromosomes exchange DNA to create genetic diversity among
offspring?
Crossing over
4. Draw a flow chart that simulates meiosis for an organism with n = 8. What is the end result of
meiosis?
5. During translation, what type of RNA carries the nitrogen base codons which are translated into
amino acids?
mRNA
6. Describe transcription, and where does transcription take place in the cell? Where does translation
take place?
mRNA takes the genetic code from the nucleus to the ribosome where translation takes place
7. The variety of finch species on the Galapagos Islands in relation to their beak sizes helps to prove
what aspect of the theory of evolution? Why is the development of different beaks for the various
finches an example of an advantageous adaptation?
8. What chemical equation describes photosynthesis?
6CO2 + 6H2O + energy C6H12O6 + 6O2
9. At what site or location does translation (protein synthesis) take place in the cell?
ribosome
10. What is the probability that two people, one heterozygous for a trait, and one homozygous
dominant for a trait, could produce offspring that are homozygous recessive for a trait?
0%
11. How can mutations, which are generally bad for organisms, be sometimes beneficial?
When it allows the organism to adapt which increases their survival
12. What nitrogen base is found during the process of transcription that is NOT found during the process
of replication?
Uracil
13. What kinds of cells are produced during meiosis?
gametes
14. What molecule is broken down to produce ATP during cellular respiration?
glucose
15. What are the genotype and phenotype ratios that would be produced from a cross between parents
that are homozygous recessive and heterozygous for a trait?
50% heterozygous
50% homozygous recessive
16. What are the four main principles of Darwin’s theory of natural selection?
17. Give an example of disruptive selection in nature and explain how it happened.
18. What are two things that can affect an enzyme’s ability to break down substances?
pH and temperature
19. What occurs in the cell during replication?
DNA doubles
20. How do the processes of both replication and transcription produce exact copies of the original
DNA?
Each base pairs with its complimentary RNA base
21. A woman that is color blind, a recessive sex-linked trait, has children with a man that is not color
blind. What is the percentage of their female offspring that would be color blind?
O%
22. What are the products of the light dependent reactions?
ATP, NADPH, H+ and O2
23. How is RNA different from DNA?
RNA is single stranded and used for protein synthesis
24. A mRNA strand has a codon that reads 5’-AUC-3’. What would the anticodon on a tRNA molecule be
that matches that codon?
3’ – UAG – 5’
25. Give an example in nature that supports Darwin’s theory of natural selection.
26. What are mutations caused by?
Any change in the DNA sequence
27. What are the monomers, or subunits, of proteins?
Amino acids
28. Diseases that affect cellular reproduction (asexual reproduction) affect what part of the cell cycle
from occurring correctly?
Mitosis (cell division)
29. What is the difference between normal body cells and gametes?
Gametes have ½ the number of chromosomes = ½ the amount of DNA
30. How many chromosomes will a daughter cell produced during mitosis have in comparison to the cell
it originated from?
Same number of chromosomes (my “twin” sis)
31. What do organisms with homologous characteristics have in common with one another?
32. What is the difference between offspring produced sexually and asexually in terms of their genetic
material?
Parents & offspring have the same genetic material but DIFFERENT acquired traits
33. What are the expected genotype and phenotype ratios for a cross between 2 parents that are both
heterozygous for a trait?
75% will have the dominant trait
25% will have the recessive trait
34. What are the expected genotype and phenotype ratios for a cross between a homozygous dominant
parent and a homozygous recessive parent?
100% heterozygous
35. What explains how there can be many different species of a similar bird type in different
environments across the United States?
36. Which part of the DNA molecule causes the expression of different traits among organisms of the
same species?
Nitrogen bases (rungs of the ladder)
37. In a population of Arctic Wolves thick fur (T) is dominant to thin fur (t). Black fur (B) is dominant to
white fur (b). What genotypes would best survive during the winter months?
TTbb or Ttbb
38. Explain why a man who is recessive for a sex-linked trait affects only his daughters, but not his sons.
Sex-linked traits are on the X chromosome and the males only have one X chromosome
39. Explain how cell differentiation produces complex multicellular organisms from zygotes.
Cells differentiate as they divide becoming specific tissues and organs
40. Where does transcription occur in the cell?
Nucleus
41. Explain how inbreeding allows rare recessive conditions to remain in a population that would
normally be bred out of larger populations that are not inbred.
42. Why is the fossil record more diverse in variety in younger rock strata than in older rock strata?
43. What occurs during anaphase of both mitosis and meiosis?
Chromosomes are pulled apart
44. What is the purpose of photosynthesis for autotrophs?
Allows plants to store energy in carbohydrate molecules
45. How many copies of chromosome pairs should gametes have from the original body cells they were
formed from?
½ the number
46. What does DNA provide for organisms?
The genetic material or code
47. What are the main differences between prokaryotic and eukaryotic cells?
Eukaryotic cells have a nucleus
48. What are people missing that causes them to be lactose intolerant?
The enzyme to digest lactose
49. What are the reactants used to make glucose during the light dependent reactions?
CO2
50. How many alleles can a parent contribute for a trait?
One
51. What would explain a decrease in fossil species from older rock strata to younger rock strata?
52. What kind of organisms undergoes meiosis, and where in the organisms are the gametes formed?
Reproductive organs in a multi-cellular organism
53. What are the only forms of life on earth that have prokaryotic cells?
Bacteria
54. Explain how genetic drift can cause different species to arise in isolated locations from their
ancestral homelands.
55. What is the expected phenotype ratio for a heterozygous dihybrid cross?
9:3:3:1