Chapter Five Section One and Two Study Guide
1.
Who is considered the “father of heredity”?
2.
Mendel concluded that _____________set(s) of instructions are present
for each _______________________. Each parent donates
_____________set(s) of instructions.
3.
When traits are passed down from parents to the next generation, what is
this called?
4.
Name the scientist who studied pea plants to determine traits and how
they are passed down from generation to generation.
5.
Why was it important that Mendel use self-pollinating plants in his
experiments?
6.
Why is it important to look at two or more generations of offspring when
looking at genetic traits?
7.
What did Mendel call the trait that always showed, if present, in the
offspring?
8.
What did Mendel call the trait that always seemed to disappear in the
offspring if a dominant trait was present?
9.
The feature that shows up in a population and has different forms, such as
hair color, is called what?
10. The different forms of the feature, such as red, brown, or blond hair is
called what?
11.
What percent of dominant and recessive traits did Mendel observe in the
first generation of his experiments? Dominant: _______%, Recessive:
_______%
12. In the second generation of Mendel’s experiments, what ratio of dominant
to recessive traits did he discover?
13. Why is it important to use large quantities of data in an experiment?
14. When parents with purebred traits are bred and each parent shows a
different trait, such a brown haired father and a blond haired mother,
which trait always shows up in the first generation of offspring?
15. When parents with purebred traits are bred and each parent shows a
different trait, such a brown haired father and a blond haired mother,
what happens to the recessive trait in the first generation?
What happens to the recessive trait in the second generation?
16. What are the instructions for an inherited trait called?
17. The different forms of a gene are called what?
18. How many alleles are contributed from each parent for a trait?
19. What are the three different possible combinations of alleles (use the
letter B – it can be used as a capital letter and as a lower case letter).
Label each combination using two of these terms: heterozygous,
homozygous dominant, homozygous recessive, purebred dominant, purebred
recessive, and hybrid.
_______: __________________________ or
__________________________
_______: __________________________ or
__________________________
_______: __________________________ or
__________________________
20. The appearance of a trait, or the physical feature you see, is called the
___________________.
21. The combination of two or more alleles of a trait makes up the
__________.
22. If there are two dominant or two recessive alleles, what is the organism
called?
23. If there are one dominant and one recessive allele, what is the organism
called?
24. What is the tool called that scientists use to predict the chance of
different genotypes occurring in offspring?
25. If both parents are heterozygous for a trait, what is the chance of seeing
the dominant trait in the offspring?
26. What is the mathematical chance that something will happen called?
27. What is it called when two parents bring together different dominant
alleles for the trait and the two alleles contribute its own influence to the
trait of the offspring (one is not dominant over the other)? An example is
when a dominant red flower cross with a dominant white flower and pink
offspring are produced.
28. What are four exceptions to Mendel’s principles?
1.
_____________________________________________________
_______
2.
_____________________________________________________
_______
3.
_____________________________________________________
_______
4.
_____________________________________________________
_______
29. A male dog is heterozygous and has a long tail (T). A female dog is short
tailed. A dog breeder wants to know the chances of the offspring showing
the different traits.
What are the chances of having a
short tailed offspring? _______
What are the chances of having a long
tailed homozygous offspring?
_______
30. Mom and Dad have no freckles and are both heterozygous (Ff). The couple
has 4 children.
- What is the chance of having a child
with no freckles? _______
- What is the chance of having a child
with freckles? _______
- Does this mean that the couple will
have 1 child with freckles and 3
children without freckles? ________
(yes or no).
Explain your answer:
________________________________________________________
________________________________________________________
________________________________________________________
________________________________________________________
________________________
Chapter Five Section One and Two Study Guide – KEY
31. Who is considered the “father of heredity?” Gregor Mendel
32. Mendel concluded that two set(s) of instructions are present for each
characteristic. Each parent donates one set(s) of instructions.
33. When traits are passed down from parents to the next generation, what is
this called? heredity
34. Name the scientist who studied pea plants to determine traits and how they
are passed down from generation to generation. Mendel
35. Why was it important that Mendel use self-pollinating plants in his
experiments? By using egg and sperm from the same plant, he was able to
create true breeding plants. By creating true breeding (purebred) plants,
Mendel guaranteed that all of the offspring of the new plant had the
same traits as the parent. The true breeding plants were his control
group because he knew what alleles these plants carried.
36. Why is it important to look at two or more generations of offspring when
looking at genetic traits? Because the first generation could carry a
recessive trait (hidden) that could show up in the next generation.
37. What did Mendel call the trait that always showed, if present, in the
offspring? dominant
38. What did Mendel call the trait that always seemed to disappear in the
offspring if a dominant trait was present? recessive
39. The feature that shows up in a population and has different forms, such as
hair color, is called what? characteristic
40. The different forms of the feature, such as red, brown, or blond hair is called
what? traits
41. What percent of dominant and recessive traits did Mendel observe in the
first generation of his experiments? Dominant: 100% Recessive: 0%
42. In the second generation of Mendel’s experiments, what ratio of dominant to
recessive traits did he discover? 3:1
43. Why is it important to use large quantities of data in an experiment? The
results are more accurate
44. When parents with purebred traits are bred and each parent shows a
different trait, such a brown haired father and a blond haired mother, which
trait always shows up in the first generation of offspring? dominant
45. When parents with purebred traits are bred and each parent shows a
different trait, such a brown haired father and a blond haired mother, what
happens to the recessive trait in the first generation? It is hidden by the
dominant trait
What happens to the recessive trait in the second generation? It may show
up- 25% chance
46. What are the instructions for an inherited trait called? genes
47. The different forms of a gene are called what? alleles
48. How many alleles are contributed from each parent for a trait? One or more
49. What are the three different possible combinations of alleles (use the letter
B). Label each combination using two of these terms: heterozygous,
homozygous dominant, homozygous recessive, purebred dominant, purebred
recessive, and hybrid.
BB – homozygous dominant, purebred dominant;
bb – homozygous recessive, purebred recessive
Bb – heterozygous, hybrid
50. The appearance of a trait, or the physical feature you see, is called the
phenotype.
51. The two alleles of a trait make up the genotype.
52. If there are two dominant or two recessive alleles, what is the organism
called? homozygous
53. If there are one dominant and one recessive allele, what is the organism
called? heterozygous
54. What is the tool called that scientists use to predict the chance of different
genotypes occurring in offspring? Punnett square
55. If both parents are heterozygous for a trait, what is the chance of seeing the
dominant trait in the offspring? 75%
56. What is the mathematical chance that something will happen called?
probability
57. What is it called when two parents bring together different dominant alleles
for the trait and the two alleles contribute its own influence to the trait of
the offspring (one is not dominant over the other)? An example is when a
dominant red flower cross with a dominant white flower and pink offspring are
produced. Incomplete dominance
58. What are four exceptions to Mendel’s principles? Incomplete dominance; one
gene many traits; many genes one trait; environmental factors
59. A male dog is heterozygous and has a long tail (T). A female dog is short
tailed. A dog breeder wants to know the chances of the offspring showing the
different traits.
Male
T
t
Tt
t
tt
Female
t
Tt
tt
What are the chances of having a
short tailed offspring? 50% (tt)
What are the chances of having a long
tailed homozygous offspring? 0% (TT)
60. Mom and Dad have no freckles and are both heterozygous (Ff). The couple has
4 children.
Female
F
F
f
FF
Ff
Ff
ff
Male
f
-What is the chance of having a child
with no freckles? 75% (FF and Ff)
-What is the chance of having a child
with freckles? 25% (ff)
-Does this mean that the couple will
have 1 child with freckles and 3
children without freckles? No (yes or
no).
Explain your answer:
Each child has a 25% (or 1 out of 4) chance of having freckles (ff) and a
75% (or 3 out of 4) chance of having no freckles (FF or Ff). Each child
has the same chance as all of the other children of inheriting the
freckles.