Download Genetics Study Guide 2/08

Genetics Study Guide 2/08
Modified True/False
Indicate whether the sentence or statement is true or false. If false, change the identified word or phrase to
make the sentence or statement true.
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1. A hybrid is the offspring of parents that have different alleles for a trait.
_________________________
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2. The sex cells produced by meiosis have twice the number of chromosomes as the parent cells.
_________________________
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3. The number of DNA bases forms a genetic code. _________________________
____
4. A mutation in a sex cell can be passed to offspring. _________________________
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5. Even if a gene has multiple alleles, a person cannot have more than three of those alleles.
_________________________
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6. Sex-linked traits that are controlled by recessive alleles are more likely to show up in males.
_________________________
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7. A male is represented by a square in a pedigree. _________________________
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8. A genetic disorder in which an abnormal form of hemoglobin is produced is hemophilia.
_________________________
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9. A doctor can look at the chromosomes of a cell in a karyotype. _________________________
Completion
Complete each sentence or statement.
10. The offspring of a ____________________ plant will always have the same alleles for a trait as
the parent.
11. Mendel used ____________________-pollination to produce purebred plants.
12. If a ____________________ allele is present, its trait will appear in the organism.
13. In pea plants, the tall-stem allele and the short-stem allele are different forms of the same
____________________.
14. If D represents the dominant allele of a gene, then ____________________ represents the
recessive allele.
15. Mendel used the principles of ____________________ to predict what percent of offspring
would show a particular trait.
16. If each of ten events is equally likely to occur, the probability of each individual event occurring
is ____________________ percent.
17. A chart used to predict results of genetic crosses is known as a(n) ____________________.
18. In a cross between two hybrid Tt pea plants, ____________________ percent of the offspring
will be Tt.
19. An organism that has two dominant or two recessive alleles is said to be ____________________
for that trait.
20. Alleles that are neither dominant nor recessive produce an inheritance pattern known as
____________________.
21. Genes are located on structures called ____________________.
22. The process in which a parent cell divides twice to produce sex cells is called
____________________.
23. If all of the sex cells of an organism have the T allele, the genotype of that organism must be
____________________.
24. The ____________________ of the DNA bases determines which protein will be produced.
25. Sets of three bases code for the production of ____________________ that make up proteins.
26. ____________________ RNA adds amino acids to a growing protein.
27. A cell produces proteins in its ribosomes during the process of ____________________.
28. The substitution of one base for another during DNA replication is an example of a(n)
____________________.
29. A mutation that has no effect on an organism is said to be ____________________.
30. A gene is said to have multiple alleles if it has more than ____________________ alleles.
31. The three alleles of the single gene that controls blood type are said to be
____________________ alleles.
32. When many genes control a trait, the trait will show a large number of ____________________.
33. Various combinations of ____________________ at each of several genes control human skin
color.
34. Improvements in medical care and in ____________________ have altered the effects of genes
on height.
35. A person's surroundings, or ____________________, can change the effects of a person's genes.
36. An egg that is fertilized by a sperm cell with a(n) ____________________ chromosome will
develop into a female.
37. A recessive allele can be passed to offspring by a(n) ____________________ who does not show
the trait.
38. A(n) ____________________ is a used to track the occurrence of a trait in a family.
39. People who have the genetic disorder called ____________________ disease suffer from a lack
of oxygen in the blood.
40. A person who has the genetic disorder called ____________________ bleeds easily.
41. Down syndrome is caused by the presence of an extra ____________________.
42. A doctor performs a procedure called ____________________ to get cells from the fluid that
surrounds a developing baby.
43. A karyotype can be used to diagnose the genetic disorder called ____________________.
44. Breeders use a technique called ____________________ to cross genetically different
individuals.
45. A gene from one organism is inserted into the DNA of another organism in the process known as
____________________.
46. ____________________ helps to solve crimes because no two people, except identical twins,
have the same DNA.
47. Scientists in the Human Genome Project are working to identify the ____________________
sequence of every human gene.
48. All of the DNA in one cell of an organism is called a(n) ____________________.
49. A selective breeding technique called ____________________ is used to breed purebred dogs.
Short Answer
50. Which trait-white flowers or purple flowers-is controlled by a dominant allele? Which is
controlled by a recessive allele? How do you know?
51. In which generation are the parents purebred? In which generation are they hybrids?
52. In the F1 generation, what is the genotype of the offspring? What is their phenotype?
53. In the F2 generation, what percent of the offspring have purple flowers? What is the genotype of
the purple-flowered offspring?
54. In the F2 generation, what percent of the offspring have white flowers? What are the genotypes of
the white-flowered offspring?
55. Suppose one of the parents of the F2 generation had been ww instead of Ww. What percent of the
offspring would have purple flowers? What percent would have white flowers?
32. Which pairs of individuals in the pedigree have children?
33. Which individuals have the trait that is traced by the pedigree?
34. Which individuals are carriers of the trait that is traced by the pedigree?
35. Which individuals neither have the trait nor are carriers?
36. Could the trait that is traced by this pedigree be sex-linked? Explain why or why not.