biology: unit 5 section 1

meiosis

A type of cell division used to produce gametes

allele

Alternative forms for a specific gene

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

dominant

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

homozygous, dominant cell

RR

F2 genertation

Second filial generation

genotype

The genes present in an organism

deviation

Variation from the predicted values

homozygous, recessive cell

rr

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

Probabilities are expressed as a number between___ and___ .

0 and 1

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 ______ .

25%

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%

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

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

true-breeding

An organism which is homozygous

dihybrid cross

Breeding of individuals which have genes for two different characteristics

The seeds collected from the first generation monohybrids are called:

F1 or hybrid

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

Genesis 1:24 Genesis 1:12

principle of segregation

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

heterozygous

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

heterozygous, dominant cell

Rr

Which symbols (genotypes) are involved in the cross to produce the F2 generation of roan cattle?

Rr x Rr

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

phenotype

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

P1 genertation

The parental generation for a given cross

tetrad

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

pollination

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

Which of these genotypes are heterozygous? TT Tt tt none of these

Tt

multiple alleles

Where more than two alternatives for a gene exist

The genotype represents:

a paired combination of genes

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

dominant

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

dominant recessive

A test cross is a cross between the unknown_______ genotype and a homozygous _________ .

dominant recessive

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

factors genes

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

homozygous definition

identical alleles

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

The outward appearance of a particular trait is called the _________ .

phenotype

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

probability

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

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

product

The calculation of probabilities is based on ________events.

random

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

segregation

heterozygous definition

unlike alleles

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

1:3

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

Punnett square

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

Which of these paired genes is homozygous? PP Pp pp PP and pp

PP and pp

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

50%

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

9:3:3:1

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

Rr x rr

self- fertilization

The organism brings the two genetically identical gametes together to offspring

Each trait characteristic of a plant is determined by:

a pair of genes

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

dihybrid

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

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

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

segregation segregate