Chapter 12 Smartbook

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

Pea

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

Polygenic trait

A parent with a genotype of RrYy can produce which of the following gametes

RY, ry, Ry, rY

Match the following rules to their descriptions

Multiplication rule= used for independent events Addition rule=used for mutually exclusive events

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

monohybrid

which term is used to refer to plant varieties in which offspring produced from self-fertilization remain uniform from one generation to the next

true-breeding

A pea plant with green seeds is allowed to self hybridize. All of the resulting offspring plants produce green seeds as well. That plant is therefore considered to be a

true-breeding plant

choose the two dominant alleles in the human ABO blood group system

Ib & Ia

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

homozygous dominant

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

optic nerve

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

pleiotropic

Which of these is commonly used to predict the results of simple genetic crosses

Punnett square

Match these four blood phenotypes with the sugar exhibited on red blood cells:

Type A: have galactosamine Type B: have galactose Type AB: have galactosamine and galactose Type O: have neither sugar

Mendel was able to produce hybrids in pea plants by using a technique called ________-pollination

cross

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

epistasis

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

pleiotropic

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

genotype

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

heterozygotes and homozygotes

A Punnett square for a single trait should be set up as a _________ square

2 X 2

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

3 dominant, 1 recessive

Which of the following is NOT a component of Mendel's five-element model

-the two alleles are usually the same -each individual receives two copies of each gene from each parent

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

0%

What type of experiment involves mating two individuals with different characteristics to each other? One individual provides females gametes, while the other provides male gametes

Hybridization

a hybridization experiment involves mating

two individuals with different characteristics to each other

A temperature-sensitive version of the enzyme ______ is responsible for the pattern of fur color in Siamese cats

tyrosinase

Which of these traits exhibit a dominant mode of inheritance

1) mid-digital hair 2) hypercholestero-lemia 3) polydactyly

Which of the following conditions is inherited due to a dominant allele

Juvenile glaucoma

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 & Yy x yy

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

independent

The following pedigree is representative of which type of inheritance ( 6 blocks in the key)

recessive

Traits that exhibit continuous variation are also called

quantitative traits

Which of the following are examples of environmental effects on phenotype

- 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

Examples of environmental influences on phenotype include

- The pattern of coat color in Himalayan rabbits -The pattern of coat color in Siamese cats

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

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

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

1/2 of the F2 individuals exhibiting the dominant form were not true breeding

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

A 3:1 phenotypic ratio in the F2 generation of a monohybrid cross represents this genotypic ratio

1:2:1

If a particular gene in a population has multiple alleles, how many alleles of that gene will a diploid individual possess

2

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 genotype Aa can produce which gametes

A and a

Assuming independent assortment, which of the following are examples of gametes produced by an AaBb individual

AB or ab

Match these traits with their characteristics in humans

Albinism=lack of melanin pigmentation Hemophilia=inability of blood to clot properly Polydactyly=extra fingers and toes Huntington disease=degeneration of nervous system Sickle cell anemia=defective hemoglobin

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 Tt

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

F1

True or False: Mendel found that plants exhibiting the recessive trait were usually not true-breeding

False

True or False: Mendel's observations did not support the independent assortment hypothesis

False

True or False: due to the diploid nature of eukaryotic cells, a gene can never have more than two alleles in a population of organisms

False

pedigree analysis is typically used for studying

Human traits that follow simple inheritance patterns

Which of these blood phenotypes is NOT properly matched with the sugar exhibited on red blood cells

Type O- have galactosamine and galactose

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

addition

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

A(n) _______ cross follows the simultaneous inheritance of two different characters

dihybrid or two-factor

Synthesis of the pigment, anthocyanin, causes purple coloration of certain plant parts, for example, seeds in certain commercial corn varieties. Because anthocyanin is made through a sequence of reactions, a gene involved in this pathway can interfere with the phenotypic expression of another gene, which leads to modified Mendelian ratios in monohybrid crosses. This is an example of ___________

epistasis

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

pedigree

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

pleiotropic

Human height is an example of a trait that has a continuous distribution of phenotypes. Human height is therefore an example of ________ inheritance

polygenic

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

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

Which of these traits is NOT correctly matched with its mode of inheritance

red-green color blindness: dominant

Which of the following takes place automatically within an individual garden pea plant if it is not disturbed

self-fertilization

Coat color in Siamese cats and Himalayan rabbits is influenced by

temperature

In order for Mendel's simple ratios to hold true, the following assumptions 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

Which term is used to refer to plant varieties in which offspring produced from self-fertilization remain uniform from one generation to the next

true-breeding

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 ________

zygote or offspring

Match each example type with the type of fertilization it represents

(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 (cross-fertilization)= pollen collected from a white flower introduced into a purple flower with male parts removed (self-fertilization)=takes place within an individual flower if it is not disturbed

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

- They were inexpensive to buy - Long generation time

Place the three stages of Mendel's experiments in the correct order

1) allowing plants to self-cross to ensure they are true-breeding 2) reciprocal crosses between true-breeding varieties 3) allowing hybrid offspring to self-fertilize

Choose statements that correctly refer to components of Mendel's five element model

1) alternative forms of genes are called alleles 2) parents transmit genes to offspring 3) the two alleles remain discrete 4) the presence of an allele doesn't ensure that it will be expressed

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

1) earlier investigators had produced hybrid peas 2) garden peas can self-fertilize 3) there were a large number of pure varieties 4) the garden pea had a relatively short generation time

Rank these steps of anthocyanin production in corn from first to last starting at the top

1) starting molecule(colorless) 2) intermediate (colorless) 3) anthocyanin (purple)

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

1/2

One of the parents in a dihybrid cross has the genotype AABb. How many types of gametes can this parent produce

2

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

50%

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

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

What type of cross follows the simultaneous inheritance of two different traits

Dihybrid cross

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

dominant

Which pattern of inheritance MOST likely explains the inheritance of the trait shown in this pedigree? (four blocks in the key)

dominant

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

heterozygotes abnd homozygotes

The result of a testcross indicate that all of the offspring have a dominant phenotype. The genotype of the parent in question must be

homozygous dominant

Match these genotypes with the correct genetic symbol

homozygous dominant= TT heterozygous=Tt homozygous recessive=tt

A 9:3:3:1 ratio is obtained in the F2 generation of a dihybrid cross when alleles assort ________ from one another

independently

an experimental cross where only a single characteristic is considered (ex. flower color) is called

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

multiplication rule

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

one trait

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

phenotype

the ______ form of a trait is the one that is not expressed in the F1 generation of a monohybrid cross

recessive

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 denoted by the letter "T", then the genotype of a dwarf pea plant is __________

tt

The probability of genotypes in an independently assorted dihybrid cross is based on the probabilities of

two monohybrid crosses