Biology U5Q1

X chromosome

A sex chromosome; in human males only one is present and in females two are present

dihybrid cross

Breeding of individuals which have genes for two different characteristics

test cross

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

F1 generation

First filial generation; the first generation from a given cross

haploid

One member of a pair of homologous chromosomes is present, such as in a gamete

Which of these paired genes is homozygous?

PP and pp

heterozygous

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

theory

The form of the hypothesis after it has been tested and found to be supported

tetrad

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

Which of these genotypes are heterozygous?

Tt

allele

tall vs. short

Why did Mendel prevent his plants from self-pollinating?

to control the crossing of the traits

Probabilities are expressed as a number between and .

0, 1

Using the group of cards just described in this section, the probability of drawing a red five is: .

1/56

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

6

DNA

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

gamete

A reproductive cell produced by the male or female parent

Y chromosome

A sex chromosome found in males; influencing the degree of maleness

autosome

Any pair of chromosomes other than the sex chromosome

diploid

Both members of a pair of chromosomes are present

Heterozygous genes will always display a dominant trait

False

homozygous, dominant cell

RR

deviation

Variation from the predicted values

multiple alleles

Where more than two alternatives for a gene exist

The results from the original crossing and the secondary crossing, can be explained by realizing that there are three alternative for hair color. Agouti is dominant over chinchilla, which is dominant over albino.

alleles

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

factors, genes

The heredity principles developed by Mendel apply only to plants.

false

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

Indicate the correct designation of the paired sex chromosomes.

male: XY, female: XX

The probability of two independent events occurring together is the of the probability of each event occurring separately.

product

homozygous, recessive cell

rr

A reptile has never been observed to give birth to a bird

true

Experiments and observations verify scientific laws.

true

Each trait characteristic of a plant is determined by:

a pair of genes

The calculation of probabilities is based on 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 pollen

If you have two coins, the probability of both coming up heads from a flip of each is .

25%

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

The seeds collected from the first generation monohybrids are called:

F 1 or hybrid

All the gene pairs from one parent can congregate in one gamete and those from the other parent in other gamete.

False

self-fertilization

The organism brings the two genetically identical gametes together to offspring

The outward appearance of a particular trait is called the .

phenotype

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

segregation

trait

A genetic characteristic of the individual

Punnett square

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

allele

Alternative forms for a specific gene

law

Supported by the results on many experiments by a large number of investigations

chromosome theory

The behavior of chromosomes explains the inheritance of genes

incomplete dominance

The blending of two traits in a heterozygous individual

genotype

The genes present in an organism

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

dominant

homozygous definition

identical alleles

homozygous

one gene tall and the other short

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

3:1

The probability of having the combination of one head and one tail when flipping two coins is .

50%

true-breeding

An organism which is homozygous

If the allele are designated (R & r) respectively, what is the probable genotypes of the round seeds which were produced?

RR, Rr

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

Rr x Rr

The genotype represents:

a paired combination of genes

heterozygous

one genes tall and the others short

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 .

probabilty

The major probability principle demonstrated in this exercise is that when two events occur at the same time, the probability of each occurrence yielding the same result is the of the probability of each separate event.

product

When flipping a coin, the chance that it will come up a head is . If you flip the coin a second time, the chance that it will come up a head again is . Let us say that you have had 25 heads come up in 25 consecutive flips. If you flip the coin one more time, the chance of coming up with a head is .

50, 50, 50

The phenotypic ratio for the F2 generation in a dihybrid cross will theoretically be _____.

9:3:3:1

recessive

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

gene

A portion of DNA which codes a specific hereditary trait

hypothesis

A proposed explanation for an observation which has not been experimentally tested

Gregor Mendel was a respected, professional scientist who introduced the science of biology.

False

dominant

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

principle of segregation

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

monohybrid cross

The breeding of two organisms which differ in a single trait

probability

The chance that a given event will occur

phenotype

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

P1 generation

The parental generation for a given cross

A cross involving true-breeding, red snapdragons and true-breeding, white snapdragons produce all pink offspring because both genes are present, neither being over the other resulting in the of the trait.

dominant, blending

A test cross is a cross between the unknown genotype and a homozygous .

dominant, recessive

A trait completely hides or masks the presence of its counterpart, the trait.

dominant, recessive

In a dihybrid cross, the F2 will have nine genotypes, but only four phenotypes because the genes cause the traits to mask the traits.

heterozygous, dominant, recessive

To determine if a particular plant is homozygous or heterozygous, you would have to test cross with a recessive.

homozygous

If the allele are designated (R & r) respectively, what is the probable genotypes of the wrinkled seeds which were produced?

rr only

With the previous cross, Rr x rr, the offspring will be .

1/2 Rr, 1/2 rr

chromosome

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

hybrid

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

homozygous

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

meiosis

A type of cell division used to produce gametes

Each P 1 parent of a monohybrid cross has completely identical genes.

False

Which scriptures describe a biologic law of reproduction for which no exception has ever been documented?

Genesis 1:24, Genesis 1:12

heterozygous, dominant cell

Rr

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

Rr x rr

F2 generation

Second filial generation

linkage

The presence of different genes on the same chromosome

pollination

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

If the allele are designated (R & r) respectively, what is the probable Phenotype of the parents?

all round

A cross between plants which differ in only two traits is a cross.

dihybrid

Each chromosome represents a single gene.

false

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

segregtion, segregate

A scientific law may be used to predict the outcome of experiments.

true

heterozygous definition

unlike alleles

A monohybrid cross is made between plants:

which differ in only one trait