Ch 3 Genetics Flashcards
(25 cards)
Mendel’s Law of Segregation is supported by a ________ testcross ratio.
Question 1 Answer
a.
3:2
b.
1:1
c.
5:2
d.
2:1
e.
3:1
1:1
The offspring of the P1 generation is known as the _______ generation.
Question 2 Answer
a.
P2
b.
F3
c.
F2
d.
F1
F1
To test Mendel’s Law of Segregation, the experimenter needs ________.
Question 3 Answer
a.
a DNA sequencing apparatus
b.
access to several generations of data
c.
a minimum of two contrasting forms of a gene
d.
the ability to perform a test cross
e.
at least 500 offspring to count
a minimum of two contrasting forms of a gene
Which of the following describes the product law?
Question 4 Answer
a.
The probabilities of two events occurring in a specific sequence are the product of their individual probabilities squared.
b.
The probability of two or more independent events occurring simultaneously is equal to the product of their individual probabilities.
c.
The probability of two or more independent events occurring simultaneously is equal to the sum of their individual probabilities.
d.
The probably of two linked events occurring simultaneously is equal to the probabilities of each individual event.
e.
The product of the sum of the probabilities of two simultaneous events describes the ability of those two events to occur together.
The probability of two or more independent events occurring simultaneously is equal to the product of their individual probabilities.
What is segregation?
Question 5 Answer
a.
Chromosomes can swap information during meiosis.
b.
Fertilization is random.
c.
During gamete formation, segregating pairs of unit factors assort independently of each other.
d.
Genes lie on chromosomes.
e.
During gamete formation, allele pairs are separated to form haploid gametes.
During gamete formation, allele pairs are separated to form haploid gametes.
Under what conditions does one expect a 1:1:1:1 ratio?
Question 6 Answer
a.
AaBb × AaBb
b.
AABB × aabb
c.
Aabb × AABB
d.
AAbb × aaBB
e.
AaBb × aabb
AaBb × aabb
Tightly curled or wooly hair is caused by a dominant gene in humans. If a heterozygous curly-haired person marries a person with straight hair, what percentage of their offspring would be expected to have straight hair?
Question 7 Answer
a.
50% straight
b.
75% curly
c.
25% curly
d.
100% straight
e.
It is impossible to predict the outcome.
50% straight
Albinism, lack of pigmentation in humans, results from an autosomal recessive gene. Two parents with normal pigmentation have an albino child. What is the probability that their next child will be wild type?
Question 8 Answer
a.
1/8
b.
0%
c.
3/16
d.
3/4
e.
1/2
3/4
A certain type of congenital deafness in humans is caused by a rare autosomal recessive gene. In a mating involving a deaf man and a deaf woman, could some of the children have normal hearing?
Question 9 Answer
a.
No, traits get passed down from father to child and the father is deaf.
b.
Yes, because it’s rare.
c.
No, because the parents would teach their children sign language.
d.
No, since the gene in question is recessive, both of the parents are homozygous and one would not expect normal hearing in the offspring.
e.
Yes, because traits assort independently.
No, since the gene in question is recessive, both of the parents are homozygous and one would not expect normal hearing in the offspring.
A recessive allele in dogs causes white spots. If two solid colored dogs are mated and produce a spotted offspring, what is the percentage chance their next puppy would be solid colored?
Question 10 Answer
a.
about 66%
b.
75%
c.
about 90%
d.
50%
e.
25%
75%
According to Mendel’s model, because of the ________ of chromosomes during meiosis, all possible combinations of gametes will be formed in equal frequency.
Question 11 Answer
a.
the product rule
b.
chromosomal theory of inheritance
c.
independent assortment
d.
law of unit factors
e.
law of segregation
independent assortment
Which types of phenotypic ratios are likely to occur in testcrosses when dealing with two gene pairs for which all the genotypic combinations are of equal viability?
Question 12 Answer
a.
9:3:3:1, 27:9:9:9:3:3:3:1
b.
1:1:1:1
c.
2:3, 1:2
d.
1:2:1, 3:1
e.
12:3:1, 9:7
1:1:1:1
What is independent assortment?
Question 13 Answer
a.
Fertilization is random.
b.
During gamete formation, segregating pairs of unit factors assort independently of each other.
c.
Genes lie on chromosomes.
d.
Chromosomes can swap information during meiosis.
e.
During gamete formation, allele pairs are separated to form haploid gametes.
During gamete formation, segregating pairs of unit factors assort independently of each other.
Under what conditions does one expect a 9:3:3:1 ratio?
Question 14 Answer
a.
dihybrid cross (F2) with independently assorting, completely dominant genes
b.
monohybrid cross (F2) with independently assorting, completely dominant genes
c.
dihybrid test cross (F2) with independently assorting, completely dominant genes
d.
dihybrid cross (F1) with independently assorting, completely dominant genes
e.
monohybrid test cross (F2) with independently assorting, completely dominant genes
dihybrid cross (F2) with independently assorting, completely dominant genes
The Chi-square test involves a statistical comparison between measured (observed) and predicted (expected) values. One generally determines degrees of freedom as ________.
Question 15 Answer
a.
ten minus the sum of the two categories
b.
the number of categories being compared
c.
the sum of the two categories
d.
one less than the number of classes being compared
e.
one more than the number of classes being compared
one less than the number of classes being compared
If an F2 generation from a self-cross always yields offspring in a 3:1 phenotypic ratio, which of the following P crosses could have occurred?
Question 16 Answer
a.
Aa × AA
b.
AA × aa
c.
aa × Aa
d.
AA × AA
e.
aa × aa
AA × aa
The number of possible gametes, each with different chromosome compositions, is 2n, where n equals ________.
Question 17 Answer
a.
the diploid number
b.
the number of genes
c.
the haploid number
d.
the number of alleles
e.
the number of offspring
the haploid number
Mendel indicated that traits were made up of unit factors. Today, we call unit factors ________.
Question 18 Answer
a.
phenotypes
b.
genotypes
c.
genes
d.
alleles
e.
characters
Genes
Assume that in a series of experiments, plants with round seeds (W) were crossed with plants with wrinkled seeds (w) and the following offspring were obtained: 220 round and 180 wrinkled. What is the most probable genotype of each parent?
Question 19 Answer
a.
Both parents are WW.
b.
Both parents are ww.
c.
Both parents are Ww.
d.
One parent is WW, the other is Ww.
e.
One parent is WW, the other is ww.
f.
One parent is ww, the other is Ww.
One parent is ww, the other is Ww.
Which two genotypes in an individual would be expressed as the same phenotype in a diploid organism?
Question 20 Answer
a.
homozygous dominant and homozygous recessive
b.
homozygous recessive and heterozygous
c.
homozygous dominant and heterozygous
homozygous dominant and heterozygous
Which types of phenotypic ratios are likely to occur in crosses when dealing with three gene pairs for which all the genotypic combinations are of equal viability?
Question 21 Answer
a.
12:3:1, 9:7
b.
1:4:6:4:1, 1:1:1:1
c.
2:3, 1:2
d.
27:9:9:9:3:3:3:1
e.
1:2:1, 3:1
27:9:9:9:3:3:3:1
What meiotic process, relative to the number of chromosomes of a given species, accounts for a significant amount of genetic variation in gametes?
Question 22 Answer
a.
pairing of homologous chromosomes
b.
formation of the meiotic spindle during chromosome segregation
c.
independent assortment of chromosomes
d.
bivalent formation
e.
trivalent formation
independent assortment of chromosomes
What is the classic Mendelian dihybrid phenotypic ratio in the F2 generation?
Question 23 Answer
a.
1:1:1:1
b.
9:1
c.
3:1
d.
9:3:3:1
9:3:3:1
In peas, gray seed color (G) is dominant to white (g). For the purposes of this question, assume that Mendel crossed plants with gray seeds with each other and the following progeny were produced: 240 gray and 80 white. What are the most probable genotypes of the parents?
Question 24 Answer
a.
Both parents are GG.
b.
Both parents are gg.
c.
Both parents are Gg.
d.
One parent is GG, the other is gg.
e.
One parent is GG, the other is Gg.
f.
One parent is gg, the other is Gg.
Both parents are Gg.
