PCB 3063 TEST 1 GENETICS LECTURE UCF
25% - Answers :If one parent is homozygous dominant for 2 genes and the other parent
is a heterozygote for both genes, what is the chance their offspring will be heterozygous
for both genes?
Anaphase 1 - Answers :At what stage of meiosis do homologs separate?
25%
1/4 x 1/4= 1/16 - Answers :What is the chance of flipping 2 coins and getting heads for
both coins?
Genotype refers to the genes or the set of alleles found within an individual.
Phenotype refers to the manifestation of a particular character or trait. - Answers :What
is the difference between genotype and phenotype?
The principle of segregation, or Mendel's first law, states that an organism possesses
two alleles for any one particular trait and that these alleles separate during the
formation of gametes. In other words, one allele goes into each gamete.
The principle of segregation is important because it explains how the genotypic ratios in
the haploid gametes are produced. - Answers :What is the principle of segregation?
Why is it important?
The concept of dominance states that when two different alleles are present in a
genotype, only the dominant allele is expressed in the phenotype. - Answers :What is
the concept of dominance?
The addition and multiplication rules are two rules of probability used by geneticists to
predict the ratios of offspring in genetic crosses.
The multiplication rule allows for predicting the probability of two or more independent
events occurring together. According to the multiplication rule, the probability of two
independent events occurring together is the product of their probabilities of occurring
independently.
The addition rule allows for predicting the likelihood of a single event that can happen in
two or more ways. It states that the probability of a single, mutually exclusive event can
be determined by adding the probabilities of the two or more different ways in which this
single event could take place. The multiplication rule allows us to predict how alleles
from each parent can combine to produce offspring, while the addition rule is useful in
predicting phenotypic ratios once the probability of eac - Answers :What are the addition
and multiplication rules of probability and when should they be used?
According to the principle of independent assortment, genes for different characteristics
that are at different loci segregate independently of one another.
, The principle of segregation indicates that the two alleles at a locus separate; the
principle of independent assortment indicates that the separation of alleles at one locus
is independent of the separation of alleles at other loci. - Answers :What is the principle
of independent assortment? How is it related to the principle of segregation?
In anaphase I of meiosis, each pair of homologous chromosomes segregate
independently of all other pairs of homologous chromosomes. The assortment is
dependent on how the homologs line up during metaphase I. This assortment of
homologs explains how genes located on different pairs of chromosomes will separate
independently of one another during anaphase I. Anaphase II results in the separation
of sister chromatids and subsequent production of gametes carrying single alleles for
each gene locus as predicted by Mendel's principle of segregation. Mendel's principles
of independent assortment and segregation do not apply to mitosis, which produces
cells genetically identical to each other and to the parent cell. - Answers :In which
phases of mitosis and meiosis are the principles of segregation and independent
assortment at work?
a. The cross of a homozygous cucumber plant that produces orange fruit (RR) with a
homozygous cucumber plant that produces cream fruit (rr) will result in an F1
generation heterozygous for the orange fruit phenotype.
P RR × rr
F1 Rr orange fruit
Intercrossing the F1 will produce F2 that are expected to show a 3:1 orange-to-
cream-fruit phenotypic ratio.
Rr × Rr
1 RR orange fruit
2 Rr orange fruit
1 rr cream fruit
b. The backcross of the F1 orange offspring (Rr) with homozygous orange parent
(RR) will produce progeny that all have the orange fruit phenotype. However,
one-half of the progeny will be expected to be homozygous for orange fruit and one-half
of the progeny will be expected to be heterozygous for orange fruit.
Rr (F1) × RR (orange parent)
½ RR orange fruit
½ Rr orange fruit
c. The backcross of the F1 offspring (Rr) with the cream parent (rr) is also a
testcross. The product of this testcr - Answers :In cucumbers, orange fruit color (R) is
dominant over cream fruit color (r). A cucumber plant homozygous for orange fruit is
crossed with a plant homozygous for cream fruit. The F1 are intercrossed to produce
the F2.
25% - Answers :If one parent is homozygous dominant for 2 genes and the other parent
is a heterozygote for both genes, what is the chance their offspring will be heterozygous
for both genes?
Anaphase 1 - Answers :At what stage of meiosis do homologs separate?
25%
1/4 x 1/4= 1/16 - Answers :What is the chance of flipping 2 coins and getting heads for
both coins?
Genotype refers to the genes or the set of alleles found within an individual.
Phenotype refers to the manifestation of a particular character or trait. - Answers :What
is the difference between genotype and phenotype?
The principle of segregation, or Mendel's first law, states that an organism possesses
two alleles for any one particular trait and that these alleles separate during the
formation of gametes. In other words, one allele goes into each gamete.
The principle of segregation is important because it explains how the genotypic ratios in
the haploid gametes are produced. - Answers :What is the principle of segregation?
Why is it important?
The concept of dominance states that when two different alleles are present in a
genotype, only the dominant allele is expressed in the phenotype. - Answers :What is
the concept of dominance?
The addition and multiplication rules are two rules of probability used by geneticists to
predict the ratios of offspring in genetic crosses.
The multiplication rule allows for predicting the probability of two or more independent
events occurring together. According to the multiplication rule, the probability of two
independent events occurring together is the product of their probabilities of occurring
independently.
The addition rule allows for predicting the likelihood of a single event that can happen in
two or more ways. It states that the probability of a single, mutually exclusive event can
be determined by adding the probabilities of the two or more different ways in which this
single event could take place. The multiplication rule allows us to predict how alleles
from each parent can combine to produce offspring, while the addition rule is useful in
predicting phenotypic ratios once the probability of eac - Answers :What are the addition
and multiplication rules of probability and when should they be used?
According to the principle of independent assortment, genes for different characteristics
that are at different loci segregate independently of one another.
, The principle of segregation indicates that the two alleles at a locus separate; the
principle of independent assortment indicates that the separation of alleles at one locus
is independent of the separation of alleles at other loci. - Answers :What is the principle
of independent assortment? How is it related to the principle of segregation?
In anaphase I of meiosis, each pair of homologous chromosomes segregate
independently of all other pairs of homologous chromosomes. The assortment is
dependent on how the homologs line up during metaphase I. This assortment of
homologs explains how genes located on different pairs of chromosomes will separate
independently of one another during anaphase I. Anaphase II results in the separation
of sister chromatids and subsequent production of gametes carrying single alleles for
each gene locus as predicted by Mendel's principle of segregation. Mendel's principles
of independent assortment and segregation do not apply to mitosis, which produces
cells genetically identical to each other and to the parent cell. - Answers :In which
phases of mitosis and meiosis are the principles of segregation and independent
assortment at work?
a. The cross of a homozygous cucumber plant that produces orange fruit (RR) with a
homozygous cucumber plant that produces cream fruit (rr) will result in an F1
generation heterozygous for the orange fruit phenotype.
P RR × rr
F1 Rr orange fruit
Intercrossing the F1 will produce F2 that are expected to show a 3:1 orange-to-
cream-fruit phenotypic ratio.
Rr × Rr
1 RR orange fruit
2 Rr orange fruit
1 rr cream fruit
b. The backcross of the F1 orange offspring (Rr) with homozygous orange parent
(RR) will produce progeny that all have the orange fruit phenotype. However,
one-half of the progeny will be expected to be homozygous for orange fruit and one-half
of the progeny will be expected to be heterozygous for orange fruit.
Rr (F1) × RR (orange parent)
½ RR orange fruit
½ Rr orange fruit
c. The backcross of the F1 offspring (Rr) with the cream parent (rr) is also a
testcross. The product of this testcr - Answers :In cucumbers, orange fruit color (R) is
dominant over cream fruit color (r). A cucumber plant homozygous for orange fruit is
crossed with a plant homozygous for cream fruit. The F1 are intercrossed to produce
the F2.
