Quiz 1: Gregor Mendel's Experiments

Indicate the phenotypic ratio of a cross between a heterozygous agouti rabbit (AC) with a homozygous chinchilla. Use the following alleles: A=agouti, C=chinchilla, a=albino, A is dominant over C and a, C is dominant over a. Assume agouti rabbits are female.

1/2 agouti, 1/2 chinchilla

Red flowered snapdragons are crossed with white flowered, producing all pink snapdragons in the F 1 . What would you expect if you crossed pink with white?

1/2 pink, 1/2 white

If you have a heterozygous yellow-seed plant (Yy), the probability of forming a "Y" gamete is ___________-. The probability of forming a "y" gamete is _____________--. This follows the principle of segregation.

50%, 50%

How many combinations of genotypes are possible for the coat coloration of rabbits which is governed by three alleles?

6

chromosome

A "threadlike" structure in the nucleus, composed of DNA

hybrid

A cross between parents which has different phenotypes for a specific trait

recessive

A gene or trait which is masked when a dominant allele is present

trait

A genetic characteristic of the individual

DNA

A giant molecule consisting of the sugar deoxyribose, phosphates and nitrogen bases

Punnett square

A grid system used to predict possible combinations of genes due to random fertilization

homozygous

A pair of genes in an organism which are identical in the way they influence a trait

gene

A portion of DNA which codes a specific hereditary trait

gamete

A reproductive cell produced by the male or female parent

meiosis

A type of cell division used to produce gametes

allele

Alternative forms for a specific gene

true-breeding

An organism which is homozygous

test cross

Breeding the individual with the dominant trait to a homozygous recessive for that trait

The seeds collected from the first generation monohybrids are called:

F 1 or hybrid

Heterozygous genes will always display a dominant trait

False

T or F? Each P 1 parent of a monohybrid cross has completely identical genes.

False

F1 generation

First filial generation; the first generation from a given cross

dominant

In a pair of genes, one may prevent the allele from being expressed

heterozygous

Refers to a pair of genes for a specific trait in an organism which are different

Which symbols (genotypes) are involved in the cross to produce the F 2 generation of roan cattle?

Rr x Rr

Choose the answer that shows the cross between roan and white cattle.

Rr x rr

F2 generation

Second filial generation

incomplete dominance

The blending of two traits in a heterozygous individual

monohybrid cross

The breeding of two organisms which differ in a single trait

probability

The chance that a given event will occur

genotype

The genes present in an organism

self-fertilization

The organism brings the two genetically identical gametes together to offspring

phenotype

The outward appearance of the organism which is the product of gene action

P1 generation

The parental generation for a given cross

tetrad

The two pairs of chromatids of the homologous pair of chromosomes comes together

T or F? A reptile has never been observed to give birth to a bird

True

multiple alleles

Where more than two alternatives for a gene exist

Each trait characteristic of a plant is determined by:

a pair of genes

The genotype represents:

a paired combination of genes

Red flowered snapdragons are crossed with white flowered, producing all pink snapdragons in the F 1 . What would you expect if you crossed red with red?

all red

Red flowered snapdragons are crossed with white flowered, producing all pink snapdragons in the F 1 . What would you expect if you crossed white with white?

all white

The characteristic which resulted from a monohybrid cross is the ___________ trait.

dominant

The controlling influence which produced distinct ratios of traits was called __________ by Mendel and are known today as __________ .

factors, genes

The difference between appearance and genetic makeup has led to the development of two terms to distinguish the two conditions. The appearance of the organism for the trait is called ________________ ; the actual genetic makeup is called __________________-.

phenotype, genotype

Genetics experiments on the breeding of plants or animals are based on the laws of _____________.

probabillity

The probability of two independent events occurring together is the (Choose... quotient sum difference product) of the probability of each event occurring separately.

product

The calculation of probabilities is based on (Choose... systematic random) events.

random

In addition to covering each pea plant to prevent pollination from other pea plants in his garden, what did Mendel do to prevent self-pollination?

remove the stamen

The reduction of a gene pair to an allele during the formation of a gamete is called the principle of _________

segregation

Mendel's first principle, the principle of ______________ , states that in the process of forming gametes, the inheritance factors for any trait always _________________ .

segregation, segregate

If you first cross an agouti rabbit with a chinchilla, and then continue to cross each subsequent generation with albinos, what will occur in the growing population?

the percentage of albinos will increase

Why did Mendel prevent his plants from self-pollinating?

to control the crossing of the traits

A monohybrid cross is made between plants:

which differ in only one trait

Red flowered snapdragons are crossed with white flowered, producing all pink snapdragons in the F 1 . What would you expect if you crossed red with pink?

1/2 red, 1/2 pink

Red flowered snapdragons are crossed with white flowered, producing all pink snapdragons in the F 1 . What would you expect if you crossed pink with pink?

1/4 red, 1/2 pink, 1/4 white

The probability of a yellow-seed plant (YY) forming a Y gamete is _____________ because the principle of segregation - one ______________ of each gene pair goes to a ______________- ; it only has "Y" alleles.

100%, allele, gamete

If you have two coins, the probability of both coming up heads from a flip of each is: Choose... 50% 100% 25% .

25%

The second generation phenotypes resulting from the cross of true-breeding monohybrid pollination will display a ratio of:

3:1

dihybrid cross

Breeding of individuals which have genes for two different characteristics

T or F? Gregor Mendel was a respected, professional scientist who introduced the science of biology.

False

The heredity principles developed by Mendel apply only to plants.

False

principle of segregation

Members of a gene pair separate during meiosis and are found in separate gametes

Suppose you have monohybrid pea plants in your garden and find that they produce round seed to wrinkled seeds in the ratio of 3:1. If the allele are designated (R & r) respectively, what is the probable genotypes of the round seeds which were produced?

RR & rr

pollination

Transfer of pollen in plants to the stigma which contains the female gamete

deviation

Variation from the predicted values

Indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. Assume all are homozygous. agouti x agouti

all agouti

Indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. Assume all are homozygous. albino x albino

all albino

Indicate the coat color and the proportion of offspring with that color for each of the following crosses of rabbits. Assume all are homozygous. chinchilla x chinchilla

all chinchilla

Suppose you have monohybrid pea plants in your garden and find that they produce round seed to wrinkled seeds in the ratio of 3:1. If the allele are designated (R & r) respectively, what is the probable Phenotype of the parents?

all round

According to scripture, all known occurrences in the laboratory of the Earth have shown that each kind of organism is limited to reproducing a similar ___________.

kind

Suppose you have monohybrid pea plants in your garden and find that they produce round seed to wrinkled seeds in the ratio of 3:1. If the allele are designated (R & r) respectively, what is the probable genotypes of the wrinkled seeds which were produced?

rr only