Genetics Ch3 Flashcards

Name the single individual whose work in the mid-1800s contributed to our understanding of the particulate nature of inheritance as well as the basic genetic transmission patterns. With which organism did this person work?
A) Gregor Mendel; Pisum sativum
B) George Beadle; Neurospora
C) Thomas Hunt Morgan; Drosophila
D) Calvin Bridges; Drosophila
E) Boris Ephrussi; Ephestia

A recessive allele in tigers causes the white tiger. If two normally pigmented tigers are mated and produce a white offspring, what percentage of their remaining offspring would be expected to have normal pigmentation?
A) 25%
B) 50%
C) about 66%
D) 75%
E) about 90%

Polydactyly is expressed when an individual has extra fingers and/or toes. Assume that a man with six fingers on each hand and six toes on each foot marries a woman with a normal number of digits. Having extra digits is caused by a dominant allele. The couple has a son with normal hands and feet, but the couple's second child has extra digits. What is the probability that their next child will have polydactyly?
A) 1/32
B) 1/8
C) 7/16
D) 1/2
E) 3/4

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?
A) 25%straight
B) 50% straight
C) 75% straight
D) 100% straight
E) It is impossible to predict the outcome.

Which types of phenotypic ratios are likely to occur in crosses when dealing with a single gene pair for which all the genotypic combinations are of equal viability?
A) 9:3:3:1, 27:9:9:9:3:3:3:1
B) 1:2:1, 3:1
C) 1:4:6:4:1, 1:1:1:1
D) 12:3:1, 9:7
E) 2:3, 1:2

Assume that a black guinea pig crossed with an albino guinea pig produced 5 black offspring. When the albino was crossed with a second black guinea pig, 4 black and 3 albino offspring were produced. What genetic explanation would apply to these data?
A) albino = recessive; black = recessive
B) albino = dominant; black = incompletely dominant
C) albino and black = codominant
D) albino = recessive; black = dominant
E) None of the answers listed are correct.

The fundamental Mendelian process that involves the separation of contrasting genetic elements at the same locus is called ________.
A) segregation.
B) independent assortment
C) continuous variation
D) discontinuous variation
E) dominance or recessiveness

Which of the following groups of scientists were influential around the year 1900 in setting the stage for our present understanding of transmission genetics?
A) Beadle, Tatum, Lederberg
B) Watson, Crick, Wilkins, Franklin
C) deVries, Correns, Tschermak, Sutton, Boveri
D) Darwin, Mendel, Lamarck
E) Hippocrates, Aristotle, Kolreuter

The Chi-square test involves a statistical comparison between measured (observed) and predicted (expected) values. One generally determines degrees of freedom as ________.
A) the number of categories being compared
B) one less than the number of classes being compared
C) one more than the number of classes being compared
D) ten minus the sum of the two categories
E) the sum of the two categories

A gene can have a maximum of two alleles

The nonfunctional form of a gene is called a wild-type allele.

Mendel's discoveries were well received and understood by his contemporaries.

Mendel's postulate of independent assortment is supported by a 1:1:1:1 testcross ratio.

A 9:3:3:1 phenotypic ratio is expected from a dihybrid testcross.

Assuming complete dominance, a 3:1 phenotypic ratio is expected from a monohybrid sib or self-cross

A 1:1 phenotypic ratio is expected from a monohybrid testcross with complete dominance

To test Mendel's Law of Segregation, the experimenter needs a minimum of two contrasting forms of a gene

Mendel's Law of Segregation is supported by a 1:1 testcross ratio.