biology 9

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. The presence of an allele doesn't ensure that it will be expressed. Parents transmit genes to offspring.

The expression of two different alleles of the same gene simultaneously in the heterozygote is called

Codominance

The probability of tossing a coin and having it land on heads is

0.5

An individual can acquire only allele(s) per trait, even if multiple alleles are present in the population.

2

Each parent carries alleles of a gene that segregate from each other during gamete formation.

2

If a particular gene in a population has multiple alleles, how many alleles can a diploid individual inherit?

2

We can use a Punnett square to predict the outcome of self-fertilization for the F1 hybrids of a monohybrid cross. In this case, the Punnett square should be set up as a Blank______ square.

2 x 2

A cross between heterozygotes for a single trait will lead to a genotypic ratio of 1:2:1. How many phenotypes will be observed if incomplete dominance is occurring?

3

In order to express a gene, a cell must first transcribe

DNA into a complementary RNA copy

IAi Type A IBIB Type B ii Type O IAIB Type A

IAi Type A IBIB Type B ii Type O IAIB Type A

A woman who has type B blood and a man who has type A blood could have children with which of the following blood types?

A, B, AB, O

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

All offspring will have round peas.

If a cross between heterozygotes for a single trait results in three separate phenotypes, which of the following types of inheritance is the likely reason?

Incomplete dominance

Segregation of alleles occurs during which of the following processes?

Meiosis

Which type of cellular division involves the pairing and subsequent segregation of homologous chromosomes?

Meiosis

The physical appearance or other observable characteristic of an individual is known as the individual's .

Phenotype

This is the idea that the two alleles of a gene separate during the formation of eggs and sperm so that every gamete receives only one allele.

Principle of Segregation

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

Punnett square

Which of the following is true about transcripts in eukaryotic cells (such as a human cell)?

RNA transcripts have to be edited to remove unnecessary information before exiting the nucleus.

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. The number of seeds eaten by a bird affects its weight.

How is the genetic information of organisms encoded in their DNA?

The information is encoded in the specific order of nucleotides in DNA.

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.

When continuous traits are graphed with the phenotype on the X-axis and the number of individuals with that phenotype on the Y-axis, a -shaped curve results.

bell

A situation where a single individual expresses two different alleles is referred to as ____.

codominance

If a true-breeding tall pea plant is crossed with a true-breeding dwarf pea plant and all of the offspring are tall plants, the trait "tall plant" is

dominant over "dwarf plant."

When the expression of one gene obscures the effects of another gene, this is called:

epistasis

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

epistasis

The entire set of DNA molecules found in a cell is referred to as that cell's:

genome

The total set of alleles a particular individual possesses is known as the individual's

genotype

An individual who carries two different alleles of a gene is termed with respect to that gene.

heterozygous

An individual with two identical alleles of a gene of a particular trait has a(n) genotype with respect to that gene.

homozygous

Consider the "tall"/"short" traits of pea plants. A pea plant that carries two "tall" alleles is

homozygous

homozygous heterozygous

homozygous individual carries two identical alleles of a gene heterozygous individual carries two different alleles of a gene

If a heterozygote displays a phenotype that is intermediate between the two homozygous individuals, then the trait must operate by ______.

incomplete dominance

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

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

monohybrid

An experimental cross where only a single characteristic is considered (for example, flower color) is called

monohybrid

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

more

Events that can not occur at the same time are called

mutually exclusive

In snapdragons, alleles resulting in red pigment and white pigment exhibit incomplete dominance. If red snapdragons are crossed with pure white snapdragons the offspring of the F1 generation will be ____.

pink

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

pleiotropic

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

pleiotropic

Continuous phenotypic variation results from

polygenic inheritance and independent segregation of genes

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

punnett

Individuals have two alleles for each gene, and when gametes form by meiosis, the two alleles

segregate

The principle of ______ is that 2 alleles for a genes separate during gamete formation and are rejoined at random, one from each parent, during fertilization.

segregation

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

that the traits are inherited independently

Examples of environmental influences on phenotype include

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

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

zygote