Genetics Exam test questions and
answers graded A+
What's homolog? With what regard to genes and alleles, how are homologs similar to and different
from each other? - ANS✅✅The term homolog refers to the members of a chromosome pair.
Homologs are usually the same size and carry the same types and order of genes. They may differ in
that the genes they carry may be different alleles.
What is a sister chromatid? Are sister chromatids genetically similar or identical? - ANS✅✅Sister
chromatids are identical copies derived from the replication of a parental chromosome. They remain
attached to each other at the centromere. They are genetically identical, barring rare mutations and
crossing over with homologous chromosomes
For following events, specify whether they occur during mitosis, meiosis 1, or meiosis II, or multiple
A. Separation of conjoined chromatids within a pair of sister chromatids
B. Pairing of homologous chromosomes
C. Alignment of chromatids along the metaphase plate
D. Attachment of sister chromatids to both poles - ANS✅✅A. During mitosis and meiosis II
B. During meiosis I (Recall that, in mitosis, homologous chromosomes do not pair together. In
mitosis, homologous chromosomes line up end-to-end so that when they divide, each daughter cell
receives a sister chromatid from both members of the homologous pair.)
C. During mitosis, meiosis I, and meiosis II
D. During mitosis and meiosis II
Describe the key events during meiosis that result in a 50% reduction in the amount of genetic
material per cell? - ANS✅✅The reduction occurs because there is a single DNA replication event
but two cell divisions. Because of the nature of separation during anaphase I, each cell receives one
copy of each type of chromosome.
The arrangement of homologs during metaphase of meiosis I is a random process. In your own
words, explain what this means? - ANS✅✅It means that the maternally derived and paternally
derived chromosomes are randomly aligned along the metaphase plate during metaphase I. Refer to
Figure 3.16.
,A cell is diploid and contains three chromosomes per set. Draw arrangement of chromosomes during
metaphase of mitosis, meiosis I, and meiosis II. Mark one set darker and one lighter. - ANS✅✅(IN
notes)
A eukaryotic cell is diploid containing 10 chromosomes (5 in each set). For mitosis and meiosis, how
many daughter cells would be produced, and how many chromosomes would each one contain? -
ANS✅✅Mitosis—two diploid cells containing 10 chromosomes each (two complete sets). Meiosis
—four haploid cells containing 5 chromosomes each (one complete set)
Who's Gregory Mendel? - ANS✅✅Considered the Father of genetics, an Austrian monk that
trained in mathematics and science, work from 1856-1863 resulted in seminal paper in 1865, printed
1866.
He breed garden peas, or PISUM sativum (easily crossable and many varieties)
He created the 4 Postulates or laws
Mendel set out his research with three questions.
1. What is inherited?
2. How is it inherited?
3. What is the role of chance in heredity? - ANS✅✅1. Variations in traits (Basically a properties of a
character, you inherit blue or brown eyes)
2. Dominant and recessive alleles (We have alternate version of alleles that are expressed with some
being dominant or recessive)
3. Probability
What Mendel did differently - ANS✅✅1. He used peas to control breeding (self vs cross
fertilization: Pollen/eggs are from same or different plants and breed)
2. Used discrete traits
3. Started with pure-breeding lines (Homozygous parent that only give one characteristic)
4. Used Reciprocal cross
5. Statistical analysis (G
cross-fertilization - ANS✅✅Pollen of a plant is put on stigma of another plant and applied to
different pollen to create a hybrid plant
Characters?
, Traits/Variant? - ANS✅✅1. General characteristics
2. Specific properties of character
Particle theory of inheritance - ANS✅✅Traits are inherited as discrete units (Now called genes)
that remain unchanged as they are passed from parent to offspring
Gene - ANS✅✅A unity of heredity
Mendel's Law of segregation - ANS✅✅the two copies of a gene segregate from each other during
transmission from parent to offspring , so only one of the two gene copies present in an organism is
distributed to each gamete (egg or sperm cell) that it makes, and the allocation of the gene copies is
random.
Mendel's Law of Independent Assortment - ANS✅✅two different genes (unit factors) will
randomly assort their alleles during the formation of haploid cells between mom and dad
Mendel's Postulates - ANS✅✅1) Genetic characters (traits) are controlled by unit factors (alleles)
that exist in pairs in individual organisms.
2) When two unlike unit factors responsible for a single characteristic are present in an individual
one unit factor is dominant to the other, which is said to be recessive.
3) During the formation of gametes the paired unit factors separate (Law of Segregation) or
segregate randomly so that each gamete receives one or the other with equal likelihood. (Fig. 2.6)
4) During gamete formation, different pairs of alleles segregate independently of each other. (Law of
Independent Assortment) (Fig. 2.9
Genetic recombination - ANS✅✅When offspring receives a combination of alleles that differs from
those in the parental generation (Independent assortment + Cross over)
Genotype - ANS✅✅An organism's genetic makeup, or allele combinations (AACc)
Homozygous - ANS✅✅Having two identical alleles for a particular gene
AA (dominant) or cc (recessive)
Heterozygous - ANS✅✅having two different alleles for a trait
answers graded A+
What's homolog? With what regard to genes and alleles, how are homologs similar to and different
from each other? - ANS✅✅The term homolog refers to the members of a chromosome pair.
Homologs are usually the same size and carry the same types and order of genes. They may differ in
that the genes they carry may be different alleles.
What is a sister chromatid? Are sister chromatids genetically similar or identical? - ANS✅✅Sister
chromatids are identical copies derived from the replication of a parental chromosome. They remain
attached to each other at the centromere. They are genetically identical, barring rare mutations and
crossing over with homologous chromosomes
For following events, specify whether they occur during mitosis, meiosis 1, or meiosis II, or multiple
A. Separation of conjoined chromatids within a pair of sister chromatids
B. Pairing of homologous chromosomes
C. Alignment of chromatids along the metaphase plate
D. Attachment of sister chromatids to both poles - ANS✅✅A. During mitosis and meiosis II
B. During meiosis I (Recall that, in mitosis, homologous chromosomes do not pair together. In
mitosis, homologous chromosomes line up end-to-end so that when they divide, each daughter cell
receives a sister chromatid from both members of the homologous pair.)
C. During mitosis, meiosis I, and meiosis II
D. During mitosis and meiosis II
Describe the key events during meiosis that result in a 50% reduction in the amount of genetic
material per cell? - ANS✅✅The reduction occurs because there is a single DNA replication event
but two cell divisions. Because of the nature of separation during anaphase I, each cell receives one
copy of each type of chromosome.
The arrangement of homologs during metaphase of meiosis I is a random process. In your own
words, explain what this means? - ANS✅✅It means that the maternally derived and paternally
derived chromosomes are randomly aligned along the metaphase plate during metaphase I. Refer to
Figure 3.16.
,A cell is diploid and contains three chromosomes per set. Draw arrangement of chromosomes during
metaphase of mitosis, meiosis I, and meiosis II. Mark one set darker and one lighter. - ANS✅✅(IN
notes)
A eukaryotic cell is diploid containing 10 chromosomes (5 in each set). For mitosis and meiosis, how
many daughter cells would be produced, and how many chromosomes would each one contain? -
ANS✅✅Mitosis—two diploid cells containing 10 chromosomes each (two complete sets). Meiosis
—four haploid cells containing 5 chromosomes each (one complete set)
Who's Gregory Mendel? - ANS✅✅Considered the Father of genetics, an Austrian monk that
trained in mathematics and science, work from 1856-1863 resulted in seminal paper in 1865, printed
1866.
He breed garden peas, or PISUM sativum (easily crossable and many varieties)
He created the 4 Postulates or laws
Mendel set out his research with three questions.
1. What is inherited?
2. How is it inherited?
3. What is the role of chance in heredity? - ANS✅✅1. Variations in traits (Basically a properties of a
character, you inherit blue or brown eyes)
2. Dominant and recessive alleles (We have alternate version of alleles that are expressed with some
being dominant or recessive)
3. Probability
What Mendel did differently - ANS✅✅1. He used peas to control breeding (self vs cross
fertilization: Pollen/eggs are from same or different plants and breed)
2. Used discrete traits
3. Started with pure-breeding lines (Homozygous parent that only give one characteristic)
4. Used Reciprocal cross
5. Statistical analysis (G
cross-fertilization - ANS✅✅Pollen of a plant is put on stigma of another plant and applied to
different pollen to create a hybrid plant
Characters?
, Traits/Variant? - ANS✅✅1. General characteristics
2. Specific properties of character
Particle theory of inheritance - ANS✅✅Traits are inherited as discrete units (Now called genes)
that remain unchanged as they are passed from parent to offspring
Gene - ANS✅✅A unity of heredity
Mendel's Law of segregation - ANS✅✅the two copies of a gene segregate from each other during
transmission from parent to offspring , so only one of the two gene copies present in an organism is
distributed to each gamete (egg or sperm cell) that it makes, and the allocation of the gene copies is
random.
Mendel's Law of Independent Assortment - ANS✅✅two different genes (unit factors) will
randomly assort their alleles during the formation of haploid cells between mom and dad
Mendel's Postulates - ANS✅✅1) Genetic characters (traits) are controlled by unit factors (alleles)
that exist in pairs in individual organisms.
2) When two unlike unit factors responsible for a single characteristic are present in an individual
one unit factor is dominant to the other, which is said to be recessive.
3) During the formation of gametes the paired unit factors separate (Law of Segregation) or
segregate randomly so that each gamete receives one or the other with equal likelihood. (Fig. 2.6)
4) During gamete formation, different pairs of alleles segregate independently of each other. (Law of
Independent Assortment) (Fig. 2.9
Genetic recombination - ANS✅✅When offspring receives a combination of alleles that differs from
those in the parental generation (Independent assortment + Cross over)
Genotype - ANS✅✅An organism's genetic makeup, or allele combinations (AACc)
Homozygous - ANS✅✅Having two identical alleles for a particular gene
AA (dominant) or cc (recessive)
Heterozygous - ANS✅✅having two different alleles for a trait
