TBPQ Chapter 12 Genetics

In a homozygous recessive individual the probability of the the dominant allele being present is

0%

In the cross of Pp x Pp four outcomes are possible: PP, Pp, pP, and pp. The probability of being heterozygous is ________.

1/2

In a certain plant, fruit color is affected by an epistatic interaction between two genes. The fruit is red in the presence of at least one dominant allele of either or both gene A or gene B, and white when there are no dominant alleles present. What proportion of the offspring of a cross of AaBb x AaBb plants is expected to be red?

15/16

When performing a monohybrid cross, Mendel noticed that not all individuals in the F2 generation were true breeding. What proportion were not?

2/3 of the F2 individuals exhibiting the dominant form were not true breeding.

What was the ratio that Mendel observed between dominant and recessive traits in the F2 offspring of a monohybrid cross?

3 dominant; 1 recessive

In a heterozygous individual, the probability of a recessive allele being present in a gamete is

50%

This ratio is obtained in the F2 generation of a dihybrid cross when alleles assort independently from one another.

9:3:3:1

An individual with Type A blood can receive transfusions of which of the following blood types?

A and O blood types

An individual with genotype Aa can produce which gamete(s)?

A and a

Assuming independent assortment, which of the following are examples of gametes produced by an AaBb individual? (they are different set of letter, but they are either IN ALL CAPS, or all lower case)

AB ab

The trait for round (R) peas is dominant over the trait wrinkled (r) peas. What would happen if true-breeding round peas are crossed with true-breeding wrinkled peas?

All offspring will have round peas.

In pea plants, the allele T encodes for tall plants, while the allele t encodes for dwarf plants. If a true-breeding tall pea plant is crossed with a true-breeding dwarf pea plant what are the expected genotypes of the offspring?

All would have the Genotype of Tt

Place the three stages of Mendel's experiments in the correct order from first (on top) to last.

Allowing plants to self-cross to ensure they are true-breeding reciprocal crosses between true-breeding varieties allowing hybrid offspring to self fertilize

Choose statements that correctly refer to components of Mendel's five-element model (please note that the answers use the modern term gene instead of factor).

Alternative forms of genes are called alleles. The two alleles remain discrete. Parents transmit genes to offspring. The presence of an allele doesn't ensure that it will be expressed.

Which of the following is NOT one of the three main stages that Mendel conducted his experiments in?

Back crosses between F1 and P individuals

In a typical monohybrid cross, all of the offspring in which generation will exhibit a single trait without blending?

F1

This generation is produced when the F1 monohybrids self fertilize:

F2

Choose the 4 reasons that contributed to Mendel selecting the garden pea as his experimental subject.

Garden peas can self-fertilize There were a larger number of pure varieties Earlier investigators had produced hybrid peas The garden pea had a relatively short generation time

Which of the following statements about the number of alleles a gene can have is true?

In a population of organisms, a gene can be represented by more than two alleles.

Mendel found that plants exhibiting the recessive trait were always true-breeding.

Just something to remember

Which of the following conditions is inherited due to a dominant allele? Juvenile glaucoma Albinism Cystic fibrosis Hemophilia

Juvenile glaucoma

Juvenile glaucoma is a hereditary disease that causes blindness due to the degeneration of nerves in which of the following?

Optic nerve

Which of the following plants was the main organism for Mendel's genetic experiments?

Pea

Which of these traits exhibit a dominant mode of inheritance?

Polydactyly Mid-digital hair Hypercholesterolemia

A trait that has multiple genes contributing to its expression is known as which of the following?

Polygenic trait

In terms of probabilities, the cross of a tall yellow seeded pea plant (TTYy) with a tall green seeded pea plant (Ttyy) is equivalent to which two monohybrid crosses?

TT x Tt and Yy x yy

Which of the following are examples of environmental effects on phenotype? The amount of sunlight experienced by a sunflower affects the number of seeds produced. A plant with a mutation in one of its genes cannot produce beta-carotene. The interaction between two genes affects the height of a plant. The number of seeds eaten by a bird affects its weight.

The amount of sunlight experienced by a sunflower affects the number of seeds produced. The number of seeds eaten by a bird affects its weight.

Which of these are not reasons that Mendel chose to study the garden pea:

They were inexpensive to buy Long generation time

What blood type is the universal recipient?

Type AB

What blood type are universal donor

Type O

When a polygenic trait is studied, individuals can be grouped in different categories based on their traits and the number of individuals per category can then be plotted to produce a histogram. The bell shaped histogram typically approaches

a normal distribution

In order to predict the outcome of mutually exclusive events, this rule should be used:

addition (used for mutually exclusive event)

A nonfunctional allele for tyrosinase is characteristic of the genetic condition called_____________.

albinism

In a monohybrid cross, the F2 generation is produced by

allowing the F1 generation to self fertilize

In a monohybrid cross, the F2 generation is produced by

allowing the F1 generation to self-fertilize

Mendel's observations supported the independent ___________hypothesis.

assortment

When continuous traits are graphed in the form of a histogram with the phenotype on the X-axis, and the frequency of individuals with that phenotype on the Y-axis, a _________________________-shaped curve results.

bell

Prior to the work of Mendel, inheritance was viewed as resulting from

blending of traits from an offspring's parents.

I^A &I^B are two alleles that are ___________ to each other

codominant

What is sickle cell anemia?

defective hemoglobin

what is Huntington disease

degeneration of nervous system

A(n) ________________cross follows the simultaneous inheritance of two different characters.

dihybrid

The form of a trait that is always expressed when crossing two true-breeding parents in a monohybrid cross is called

dominant

When the interaction of genes alters genetic ratios, this is called ________________

epistasis

What is polydactyly?

extra fingers or toes

An individual's total set of alleles for a particular trait is called his/her

genotype

Blood Type: A

have galactosamine

Blood Type: AB

have galactosamine and galactose

Blood Type: B

have galactose

Blood Type: O

have neither sugar

Consider a testcross where the unknown parent is heterozygous. The offspring will be

heterozygotes and homozygotes

If the offspring from a testcross contain only heterozygotes, the genotype of the unknown parent must be

homozygous dominant

Match these genotypes with the correct genetic symbols. homozygous dominant heterozygous homozygous recessive

homozygous dominant------------------TT heterozygous----------------------------Tt homozygous recessive------------------tt

Pedigree analysis is typically used for studying:

human traits that follow simple inheritance pattern

What is hemophilia?

inability of blood to clot properly

The appropriate time to use the product rule is when dealing with events that are:

independent

When two consecutive events occur, each one with its own probability (that does not depend on the the probability of the other event), we say that the two events are

independent

What is albinism?

lack of melanin pigment

A cross in which only a single trait is considered is called a(n)__________ cross or single factor cross.

monohybrid

The inheritance patterns of many traits are (more or less) complex than simple Mendelian patterns.

more

In order to determine the likelihood of having a flipped coin come up on heads three times in a row, you would use the (used for independent events)

multiplication rule

Events that cannot occur at the same time are called

mutually exclusive

In a _______________distribution, the values of a variable are distributed around a mean within a certain spread, which indicates the amount of variation in the variable.

normal

A Punnett square has rows and columns which represent gametes made by males and females. At the intersection of each row and column we combine the corresponding gametes to produce the genotype of a potential .

offspring or zygote

Mutations in how many genes cause the symptoms of cystic fibrosis?

one

In the monohybrid crosses performed by Mendel, the F1 plants always displayed ____.

one trait

This analysis is appropriate for studying traits, such as genetic diseases, that follow simple Mendelian patterns:

pedigree

The physical appearance or other observable characteristic of an individual is called his/her .

phenotype

Sickle cell anemia is caused by a ______________________allele because this mutation has more than one effect on the phenotype.

pleiotropic

The mutation that causes cystic fibrosis affects several traits and is, therefore, an example of a(n)

pleiotropic mutation.

An allele that has more than one effect on phenotype is called

pleiotropic.

cross-fertilization

pollen collected from a white flower placed introduced into a purple flower with male parts removed

reciprocal fertilization

pollen from a white-flowered plant is used to fertilize a purple-flowered plant, while pollen from a purple-flowered plant is used to fertilize a white-flowered plant

Human height is an example of a trait that has a continuous distribution of phenotypes. Human height is therefore an example of ___________________________inheritance. (Quantitative traits are usually)

polygenic

Continuous phenotypic variation results from

polygenic inheritance and independent segregation of genes

To calculate the probability that if a woman has four children, they will all be girls, you should use the

product rule (multiplication)

A(n) _________square can be used to predict the outcome of a simple genetic cross.

punnett

Traits that exhibit continuous variation are also called

quantitative traits

The ______________form of a trait is the one that is not expressed in the F1 generation of a monohybrid cross.

recessive

An example of a _____________cross is using pollen from a green-seeded pea plant to fertilize a yellow-seeded pea plant and then using pollen from a yellow-seeded pea plant to fertilize a green-seeded pea plant.

reciprocal

self-fertilization

takes place within an individual flower if it is not disturbed

Coat color in Siamese cats and Himalayan rabbits is influenced by pH temperature codominance multiple genes

temperature

In order for Mendel's simple ratios to hold true, the following assumption must be made:

that the traits are inherited independently

In Mendel's experiments, he observed a 3:1 ratio between dominant and recessive traits in

the F2 generation of monohybrid crosses.

Examples of environmental influences on phenotype include the ABO blood types in humans the pattern of coat color in Himalayan rabbits the pattern of coat color in Siamese cats

the pattern of coat color in Himalayan rabbits the pattern of coat color in Siamese cats

Which of the following is NOT a component of Mendel's five-element model (please note that the answers use the modern term gene instead of factor)?

the two alleles are usually the same

Prior to the 20th century, the two main ideas that provided the basis for most thinking about heredity were

traits are transmitted directly from parents to offspring heredity occurs within species

One of the traits that Mendel studied in pea plant is plant height. Tall plants are dominant with respect to dwarf plants. If the gene for this trait is denoted by the letter "T", then the genotype of a dwarf pea plant is .

tt (short)

A temperature-sensitive version of the enzyme___________is responsible for the pattern of fur color in Siamese cats

tyrosinase