USF El-Rady Exam 1 Concept Checks

Which genotype is normally not found in a gamete?

aa

3 multiple choice options

Which is the most correct description of a dominant trait?

The trait that is seen in a heterozygous organism

3 multiple choice options

Which of the following is an example of a test cross?

A-bb X aabb

3 multiple choice options

Which of the following dihybrid crosses will produce offspring in a 1:1 ratio?

AaBB x aaBB

3 multiple choice options

A cross between two AaBbCcDd plants yields ______ different genotypes in the offspring. Assume independent assortment.

81

Because # of different genotypes is 3^n

n is for heterozygous

A cross between two AaBbCcDd plants yields ______ different phenotypes in the offspring. Assume independent assortment.

16

Because # of different phenotypes is 2^n

n is for heterozygous

How many different types of gametes are produced by an individual with genotype AABbccDDeeFFgg?

2

Because # of different gametes is 2^n

n is for heterozygous

The normal cloven-footed condition in swine is produced by the recessive allele m, while the mule-footed condition is produced by the dominant allele M. White coat color is governed by the dominant allele of another locus B, and black by its recessive allele b. A black mule-footed sow (female pig) is mated with a white cloven-footed boar (male pig). All of their 36 offspring are white, but 17 have mule feet and 19 have cloven feet. What are the probable genotypes of the parents?

Mmbb and mmBB, respectively

3 multiple choice options

In the garden pea, tall vine (D) is dominant over dwarf (d), green pod (Y) is dominant over yellow (y) and round seed (W) is dominant over wrinkled (w). A tall, yellow, round plant is crossed to a dwarf, green, round one. The following ratios occurred in the F1 generation: 3/8 tall, green, round; 3/8 dwarf, green round; 1/8 tall, green, wrinkled; and 1/8 dwarf, green, wrinkled. What is the genotype of the two parental plants?

DdyyWw and ddYYWw

3 multiple choice options

Consider the garden pea cross WwGg X WwGg, where W = round, w = wrinkled, G = yellow and g = green. What proportion of the offspring is expected to be round, green AND true-breeding?

1/16

In the leghorn breed of chicken, white plumage is dominant over colored plumage, feathered shanks are dominant over clean shanks, and pea comb is dominant over single comb. The three genes assort independently. A homozygous white, feathered, pea-combed chicken is crossed with a colored, clean, single-combed chicken, and the F1 progeny are allowed to interbreed. What proportion of the F2 class will produce only white, feathered pea-combed chicken if mated to colored, clean, single-combed birds?

1/64

Consider five independently assorting gene pairs, A/a, B/b, C/c, D/d and E/e, where each demonstrates complete dominance (A_, B_, C_, D_, and E_) and recessiveness (aa, bb, cc, dd and ee). An individual with genotype AaBbCCddEe is crossed to an individual with genotype AABbCcDdEe. What is the probability of obtaining an offspring with genotype AABbCcDdee?

1/64

Consider five independently assorting gene pairs, A/a, B/b, C/c, D/d and E/e, where each demonstrates complete dominance (A_, B_, C_, D_, and E_) and recessiveness (aa, bb, cc, dd and ee). An individual with genotype AaBbCCddEe is crossed to an individual with genotype AABbCcDdEe. What is the probability of obtaining an offspring that is dominant for all five traits?

9/32

Albinism is an autosomal recessive condition characterized by absence of melanin pigment from the skin, eye and hair. Two carriers of albinism marry and plan to have four children. Assume a 1:1 sex ratio. What is the probability that all their children will be normal girls?

0.020

Albinism is an autosomal recessive disorder. Two parents with normal pigmentation have an albino child. What is the probability that their next 4 children will consist of two albinos and two with normal pigmentation, in any order?

27/128

Consider the cross AaBbCCDd x aaBBccDd. If the genes are independently assorting, how many different genotypes are possible in the offspring?

none of these choices

3 multiple choice options

The probability of a couple having three girls out of five offspring

Binomial theorem

The probability that one or another event will occur in the next generation

Sum rule

The probability of an event occuring in a specific order each time

Product rule

What is the probability of throwing two six-sided dice and obtaining two 3s?

1/36

What is the probability of flipping a coin six times, and getting three heads in a row, followed by three tails?

1/64

What is the probability of flipping a coin six times, and getting three heads and three tails in any order?

5/16

A family has five kids. What is the probability that they are all female?

1/32

Albinism is an autosomal recessive condition characterized by absence of melanin pigment from the skin, eye and hair. Two carriers of albinism marry and plan to have FIVE children. Assume a 1:1 sex ratio. What is the probability that at least 3 children will be normal?

0.896

3 multiple choice options

In a chi-square test, the usual level of significance is

0.05

A mating of two red-colored insects produced 1080 offspring, including 240 that were black. You suspect that insect color is under the control of a single gene, with the dominant allele producing red color, and the recessive allele producing black. Therefore, you propose a null hypothesis of a simple monohybrid cross. What is the chi-square value for this experiment?

4.44

Use the table of chi-square values in our textbook to determine the "goodness of fit" of the data in the previous question.

0.01 < p < 0.05

3 multiple choice options

What can be said about the null hypothesis of question 26?

It is rejected

1) A cross was made to produce Drosophila melanogaster flies heterozygous for two pairs of alleles: dp+ and dp, which determine long versus short wings, and e+ and e, which determine gray versus ebony body color. The following F2 data were obtained:

Long wing, gray body 462

Long wing, ebony body 167

Short wing, gray body 127

Short wing, ebony body 44

Your null hypothesis is that the data fit the ratio 9:3:3:1. What is the expected number of individuals with long wings and gray bodies?

2) Refer to the data in the previous question. What is the chi-square value for this experiment?

1) 450

2) 6.48

3 multiple choice options

Which of these factors provides evidence that the disorder may have a genetic cause?

An increased frequency of the disorder in blood relatives of an affected individual than in the general population.

Three common explanations for autosomal dominant disorders

1: haploinsufficiency

2: gain-of-function

3: negative

Colorblindness is an X-linked recessive trait. A phenotypically normal man and a colorblind woman have four sons. What is the probability that all four of them are color blind? Assume no new mutations.

1/1

3 multiple choice options

Hemophilia and colorblindness are both X-linked, recessive traits. A hemophiliac woman marries a colorblind man. Assume that both are otherwise normal. If meiosis occurs normally for both parents, what phenotypes are possible among their offspring?

Phenotypically normal daughters and hemophiliac sons

3 multiple choice options

Barbara's first son has hemophilia, an X-linked recessive disorder. What is the probability that her next son will be hemophiliac?

Cannot be determined without knowing Barbara's genotype

3 multiple choice options

Colorblindness is an X-linked recessive trait. A couple has two sons: one with normal vision and the other is color-blind. Which of the following statements HAS to be TRUE?

None of the choices

3 multiple choice options

Duchenne muscular dystrophy is an X-linked recessive disease. A phenotypically normal couple wants to start a family. The woman's brother has the disease. What is the probability that the couple's first child will be affected?

1/8

3 multiple choice options

In a particular plant, height is under the control of a single gene that has two alleles: the dominant A (Tall) and the recessive a (Dwarf). A cross of two heterozygous tall plants produces 200 offspring, of which 120 are tall. What is the penetrance of the dominant height allele?

80%

3 multiple choice options

Genetic heterogeneity could be described as

a situation where people with the same phenotype have different genotypes.

Example of phenocopy is the drug____which could produce a phenotype similar to the genetic disease____

1: thalidomide

2: phocomelia

Which of the following statements about PrP^C is true?

All of the choices

3 multiple choice options

Which is possible modes of inheritance?

Autosomal dominant

Autosomal recessive

X-linked recessive

Which modes of inheritance are possible for this pedigree?

Autosomal dominant

Autosomal recessive

X-linked recessive

X-linked dominant

Which modes of inheritance are possible for this pedigree?

Autosomal recessive

Which modes of inheritance are possible for this pedigree?

Autosomal dominant

X-linked dominant

Which modes of inheritance are possible for this pedigree?

Autosomal dominant

Autosomal recessive

X-linked recessive

Which of the following statements is TRUE?

Neither are true

3 multiple choice options

Consider the following four sets of parents:

Set I: AB type father and AB type mother

Set II: AB type father and O type mother

Set III: B type father and A type mother

Set IV: AB type father and B type mother

How many sets could possibly produce a baby with type blood O?

Refer to the sets of parents in question 2. How many sets could possibly produce a baby with type blood AB?

1

3

3 multiple choice options

Which of the following sets of children could NOT be the biological children of a man with blood type B, M and a woman with blood type A, MN?

a child with blood type A, N and a child with blood type B, N

3 multiple choice options

A man with type O blood has

neither A nor B antigens on the surface of his red blood cells.

The "universal recipient" type is

AB

The "universal donor" type is

O

A person with blood type B can give blood to people with blood types

B and AB only.

Consider a human autosomal gene with four alleles. The number of different genotypes that are possible is

10

An autosomal gene in humans has four alleles with the dominance hierarchy A1 > A2 > A3 = A4. How many different phenotypes are possible in the population?

5

3 multiple choice options

In mallard ducks, plumage color is controlled by a gene with three alleles: M^R for restricted pattern, M for mallard and m for dusky. The dominance hierarchy is M^R > M > m. What is the genotypic ratio expected in the offspring of the mating M^RM x Mm.

1:1:1:1

In beetle, two independently assorting genes, P and C, control the thorax pattern and color, respectively. Thorax pattern can be square (PP), circular (Pp) or absent (pp). Thorax color can be red (CC), pink (Cc) or white (cc). Two dihybrid beetles are crossed. What proportion of the offspring is expected to have a thorax with pink squares?

Refer to the mating in question 11. What proportion of the offspring is expected to have a thorax with a colored pattern?

1/8

9/16

3 multiple choice options

In humans, how many different genotypes are possible for an X-linked gene with four alleles?

14

Huntington chorea is a disease caused by

a dominant lethal allele

A woman finds out that both of her parents have Huntington disease. What is the probability that she will develop the disease? Assume the Huntington allele is completely penetrant.

2/3

3 multiple choice options

The phenomenon in which a single gene affects a number of seemingly unrelated characters is

pleiotropy

Sickle cell trait is common in individuals of ________ descent because of the prevalence of _________ in that continent.

African; malaria

Duplicate gene action produces a phenotypic ratio of

15:1

The genes R, E and D are independently assorting and control production of red pigment as follows (recessive alleles are not functional)

RREEDD and rreedd individuals are crossed, and their offspring are testcrossed. What proportion of the F2 progeny is expected to be red?

Refer to the pathway of question 19. If RrEEDd and RrEEDd individuals are crossed, what proportion of the progeny is expected to be yellow?

1/8

3/16

3 multiple choice options

In the “sheperd’s purse” weed, Capsella bursa-pastoris, fruit shape is governed by two independently assorting genes, A and B. Double recessive (aabb) fruits are narrow-shaped (ovoid). The presence of at least one dominant allele at either locus results in a heart-shaped (triangular) fruit. What is the expected phenotypic ratio in the offspring of an AaBb x aabb cross?

12 heart-shaped:4 narrow-shaped

In a particular animal, coat color is under the control of two independently assorting genes, A and B. Animals can be gray (A-B-), cinnamon (A-bb), black (aaB-) or brown (aaabb). Which of the following crosses will yield offspring in a ratio of 3/4 gray : 1/4 cinnamon?

AABb x aaBb

3 multiple choice options

Genes A, B, and C are independently assorting and control production of a black pigment. The dominant alleles A, B and C code for functional enzymes whereas the recessive alleles a, b, and c code for nonfunctional enzymes. An individual of genotype AABBCC is crossed with one of genotype aabbcc, and the resulting F1 individuals are cross-fertilized.For the following pathway state what proportion of the F2 progeny is colorless?

37/64

3 multiple choice options

Genes A, B, and C are independently assorting and control production of a black pigment. The dominant alleles A, B and C code for functional enzymes whereas the recessive alleles a, b, and c code for nonfunctional enzymes. An individual of genotype AABBCC is crossed with one of genotype aabbcc, and the resulting F1 individuals are cross-fertilized.For the following pathway state what proportion of the F2 progeny is colorless?

none of these

3 multiple choice options

Tail and neck plumage in domestic fowl is an example of ______that is under control of an ____gene

Sex-limited inheritance

Autosomal

In Suffolk sheep, a single locus with two alleles controls the presence or absence of horns, with horned (H) being dominant to hornless (h). In males the genotypes HH or Hh have horns, and hh is hornless; in females the genotype HH has horns, and Hh or hh are hornless. Two hornless sheep are mated and produce a male lamb with horns. What are the genotypes of the hornless parents?

Male hh and female Hh

A pattern bald woman is married to a pattern bald man. They are expecting a girl. What is the probability that she will develop pattern baldness?

cannot determine from the given information

3 multiple choice options

A woman who has blood genotype I^BI^O marries a man with blood genotype I^AI^O. Both are heterozygous for the H-substance. What is the probability that they will have a child with blood type AB?

3/16

3 multiple choice options

Mickey and Minnie are carriers of albinism, an autosomal recessive trait. Their son Donald is phenotypically normal. What is the probability that he is a carrier?

2/3

3 multiple choice options

Bob has blood type A+, and Barb has blood type B+. Their first child has blood type O-. The probability (in fractions) that their next two children consist of a boy with blood type A+ and then a girl with blood type O- is

0.0026

Polygenic inheritance gives rise to quantitative traits that vary along a continuum or a gradient.

True

1 multiple choice option

In polygenic inheritance, the phenotype of an allele of one gene depends on the action of alleles of other genes.

False

1 multiple choice option

In polygenic inheritance, genes are typically equivalent in their contributions.

True

1 multiple choice option

Genetics is the study of ____ in all its manifestations and it revolves around____?

Heredity and genes

Study of genetics is important for two main reasons

1) It unifies the study of biology

2) It has a profound impact on human affairs

Domestication of animals began around

13,000 BC

Cultivation of plants began around

8,000 BC

Who provided the first formal explanations of heredity and variation

The ancient greek philosophers

Hippocrates basically said

Semen is secreted by whole body: healthy by healthy parts and sick by sick parts.

Democritus said

"More people become able by exercise than by their natural predisposition."

Basically suggesting that nurture is more important than nature.

Plato advocated for?

the selection of spouses to produce children who will develop into bodily and ethically eminent personalities

Basically early eugenics

Aristotle developed what?

The comprehensive theory of inheritance.

Male semen was the "form" and came from the blood

Menstrual blood contained the "matter"

Form shaped the matter into mature offspring.

William Harvey proposed what?

The Theory of Epigenesis

The Theory of Epigenesis is?

An idea introduced by Harvey.

All things originate from the egg and that all parts are present in the embryo.

Which evolves by gradual building of these parts

Anton van Leeuwenhoek discovered what?

Spermatozoa.

Anton van Leeuwenhoek speculated what after his discovery?

That sperm provides essential life-giving properties. The egg is provides environment and embryo is nutrition.

What is the Theory of Preformationism

organism is in one of the sex cells fully developed, the homunculus.

With proper nourishment the homunculus unfolds into its adult proportions.

What is the fully developed organism called in Preformationism?

homunculus

Spermists believed?

the homunculus was found in the sperm

Ovists believed?

the homunculus resided in the egg

Caspar Wolff discredited what?

The Theory of Preformationism

Who proposed the first theory of evolution?

Jean Baptiste de Lamarck

The Theory of the Inheritance of Acquired Characterisitcs had two major laws:

1) Change in the environment

2) All changes of such nature are inherited.

What did Charles Darwin propose?

Theory of Organic Evolution by Natural Selection

Darwin's Theory demolished what?

the Linnaean concept of fixity of species

Because of criticism Charles Darwin then proposed

The Provisional Hypothesis of Pangenesis

Darwin's Pangenesis stated?

Cells of developing organism produce gemmules, which are copies of each body part. These gemmules travel by the blood and into reproductive organs and assemble gametes.