Download Genetics Review Questions

2nd Nine Weeks Benchmark Review Questions
Answer Key
1. If “R” represents the gene for round seeds and “r” represents the gene for wrinkled seeds,
which is a hybrid?
a. Rr
b. RR
c. rr
d. none of these
2. What is the basic unit of heredity? genes
3. Who studied the inheritance patterns of pea plants and is the “Father of Genetics”? Mendel
4. A gene that masks or hides other genes is called dominant.
5. Recessive traits are not expressed unless the offspring inherit a recessive gene from each parent.
6. Dominant genes are represented by a capital letter, while a recessive gene is represented by a
lowercase letter.
7. PP and pp represent a purebred organism.
8. A hybrid gene pair is also referred to as heterozygous.
9. Offspring inherit one gene from each parent.
10. Pp has genes that are different and represent a hybrid organism.
11. The likelihood that an event may or may not take place is called probability.
12. What is the probability that a child will be male? 50% or 1 in 2
13. In a punnett square, what does each square represent? possible combinations of alleles that can
result from a genetic cross
14. Visible characteristics are called traits (I would also accept phenotype).
15. The actual gene make-up of an organism is called a genotype.
16. If B represents the dominant gene for brown fur, what would be the genotype for a guinea pig that
is heterozygous for brown fur? Bb
17. How is it possible for tall-stemmed parent plants to produce offspring that are short-stemmed?
Both parents would have to be hybrids (Tt x Tt).
18. If a smooth pea pod is represented by an “S” and a pinched pea pod by an “s”, what is the
phenotype of an “Ss” pea pod? smooth
19. Why did Mendel study pea plants? (3 reasons)
a) variety of traits
b) grow and reproduce quickly
c) crossed and bred easily
20. What is pollination? transfer of pollen from male structure to female structure
21. What is self-pollination? pollen from a flower lands on the pistil of the same
plant
22. What is cross-pollination? pollen from a flower lands on the pistil of another
plant
23. List 4 things Mendel concluded from his experiments. (pg. 113)
a) Individual factors control the inheritance of traits.
b) These “factors” exist in pairs.
c) The female parent contributes on factor, and the male parent contributes
one factor.
d) One factor in a pair can mask or hide the other factor.
24. Different forms of a gene are called? alleles
25. How would you write two dominant alleles for tall stems? TT
26. How would you write two recessive alleles for short stems? tt
27. How would you write a hybrid genotype for tall stems? Tt
28. Does probability predict what will definitely occur? No, it only predicts
possibilities.
29. Each time you toss a coin, what 2 ways can it land? heads or tails How do you
write this in mathematical terms? ½ or 50%
30. If a homozygous white-haired guinea pig (WW) is crossed with a heterozygous
white-haired guinea pig (Ww), what percentage of their offspring will be black?
0% will be white
31. What are the rod-shaped structures found in the nucleus of every cell?
chromosomes
32. What is a mutation? a sudden change in a gene or chromosome
33. Give two examples of harmful mutations. albino deer and sickle cell anemia
34. What is meiosis? process of cell division that creates sex cells
35. List the correct pairings of nitrogen bases in DNA.
adenine pairs with thymine
cytosine pairs with guanine
36. List the correct pairings of nitrogen bases in RNA.
adenine pairs with uracil
cytosine pairs with guanine
37. List three differences between RNA and DNA.
RNA is a single strand; DNA is a double strand
RNA contains ribose; DNA contains deoxyribose
RNA contains uracil; DNA contains thymine
38. In humans, the diploid number is 46 and the haploid number is 23.
39. List the function for the following organelles:
a. cell membrane-- controls what enters and leaves the cell
b. cell wal-- provides shape and support for the cell
c. nucleus-- control center of the cell
d. mitochondria-- “powerhouse”—converts food energy to usable energy
e. vacuole-- stores food and/or waste
f. lysosome-- releases chemicals that break food and waste in the cell
40. What are the products of photosynthesis? oxygen and sugar
41. How are photosynthesis and respiration related? They are opposite processes or
equations.
42. What is a eukaryote? a cell that contains a nucleus
43. What is the main difference between vascular and nonvascular plants? The main
difference between vascular and nonvascular plants is how they transport
materials.
44. Name the two stages in the life cycle of a plant. sporophyte and gametophyte
45. What is the stomata? opening on the underside of a leaf through which gases
are exchanged