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