General Biology I - BSC 1010C - Cumulative Final Exam
Study Guide Questions With Complete Solutions
At what point in meiosis does independent assortment of
homologous chromosomes occur? Correct Answers
Independent assortment of homologous chromosomes occurs in
Metaphase I of meiosis.
Concentration gradient Correct Answers A region along which
the concentration of a chemical substance in a solution increases
or decreases.
Describe descent with modification. Why are cells, DNA,
mutations, and reproductive success important to this concept?
Correct Answers - Descent with modification: Passing traits
from parent to offspring, a line of ancestry that means change.
As living organisms live and evolve they slowly change over
time.
- Cells: Carry the DNA
- DNA: Genetic makeup; includes instructions to make proteins.
Small modifications occur in DNA every time an offspring
descends from its parents. These modifications happen because
of replication and recombination of the parents' DNA and
because of random mutations in the resulting DNA of the
offspring.
- Mutations: Changes in DNA. Random mutations occur when
parents reproduce resulting in the DNA of the offspring
changing.
- Sexual reproduction: Small modifications occur in DNA every
time an offspring descends from its parents.
,- Reproductive success: To evolve and change over time, you
need to be able to reproduce. This allows the mixing of DNA
and mutations to both further the existence of an organism.
Describe Griffith's experiment, how did the results support that a
molecule was responsible for transmitting genetic information?
Correct Answers Frederick Griffith studied two strains of the
bacterium Streptococcus pneumoniae: the S (smooth) strain and
the R (rough) strain. The living S cells were deadly to the mice,
while the living R cells were non-deadly. When Griffith killed S
cells with heat and injected them into the mice, the mice
remained healthy. When he combined heat-killed S cells and
living R cells, the mice died. In the mouse's blood sample, living
S cells were found; they could reproduce, yielding more S cells.
Griffith concluded that horizontal gene transfer was occurring
from dead S-cells to living R-cells. His experiment showed that
some molecules represented genetic information, which was
moving from one bacteria to another.
Describe how covalent bonds and hydrogen bonds apply to
water molecules. Correct Answers Polar covalent bonds hold
oxygen and hydrogen atoms together, and hydrogen bonding
attracts water molecules, making up water.
Describe Mendel's law of independent assortment, how did he
use a dihybrid cross to provide evidence that supported his
hypothesis? Correct Answers Mendel's law of independent
assortment states that each pair of alleles segregates
independently of each other pair during gamete formation; it
only applies to genes on non-homologous chromosomes (non-
linked). He worked out this second law of inheritance by
, following two characters at the same time: seed color and seed
shape. Seeds could either be yellow or green, and round or
wrinkled. He performed a dihybrid cross with heterozygous pea
plants, which resulted in four phenotypic categories with a
9:3:3:1 ratio -- 9 yellow round, 3 green round, 3 yellow
wrinkled, and 1 green wrinkled, as predicted. These results
supported his hypothesis because the alleles for each tested gene
segregated independently from the alleles of the other genes.
Describe the role of each enzyme involved in DNA replication.
Correct Answers - The origin of replication is where the
replication of a DNA molecule begins, consisting of a specific
sequence of nucleotides.
- The replication fork is a Y-shaped region on a replicating DNA
molecule where the parental strands are being unwound and new
strands are being synthesized.
- Helicase is an enzyme that untwists the double helix of DNA at
the replication forks.
- Primase is an enzyme that joins RNA nucleotides to make a
primer during DNA replication, using the parental DNA strand
as a template.
- The primer is a short polynucleotide with a free 3' end that
contains RNA nucleotides.
- Okazaki fragments are short segments of DNA synthesized
away from the replication fork on a template strand during DNA
replication, making up the lagging strand.
- DNA polymerase III is an enzyme that adds DNA nucleotides
to the RNA primer; it can add nucleotides only to the free 3' end
of a primer or growing DNA strand.
Study Guide Questions With Complete Solutions
At what point in meiosis does independent assortment of
homologous chromosomes occur? Correct Answers
Independent assortment of homologous chromosomes occurs in
Metaphase I of meiosis.
Concentration gradient Correct Answers A region along which
the concentration of a chemical substance in a solution increases
or decreases.
Describe descent with modification. Why are cells, DNA,
mutations, and reproductive success important to this concept?
Correct Answers - Descent with modification: Passing traits
from parent to offspring, a line of ancestry that means change.
As living organisms live and evolve they slowly change over
time.
- Cells: Carry the DNA
- DNA: Genetic makeup; includes instructions to make proteins.
Small modifications occur in DNA every time an offspring
descends from its parents. These modifications happen because
of replication and recombination of the parents' DNA and
because of random mutations in the resulting DNA of the
offspring.
- Mutations: Changes in DNA. Random mutations occur when
parents reproduce resulting in the DNA of the offspring
changing.
- Sexual reproduction: Small modifications occur in DNA every
time an offspring descends from its parents.
,- Reproductive success: To evolve and change over time, you
need to be able to reproduce. This allows the mixing of DNA
and mutations to both further the existence of an organism.
Describe Griffith's experiment, how did the results support that a
molecule was responsible for transmitting genetic information?
Correct Answers Frederick Griffith studied two strains of the
bacterium Streptococcus pneumoniae: the S (smooth) strain and
the R (rough) strain. The living S cells were deadly to the mice,
while the living R cells were non-deadly. When Griffith killed S
cells with heat and injected them into the mice, the mice
remained healthy. When he combined heat-killed S cells and
living R cells, the mice died. In the mouse's blood sample, living
S cells were found; they could reproduce, yielding more S cells.
Griffith concluded that horizontal gene transfer was occurring
from dead S-cells to living R-cells. His experiment showed that
some molecules represented genetic information, which was
moving from one bacteria to another.
Describe how covalent bonds and hydrogen bonds apply to
water molecules. Correct Answers Polar covalent bonds hold
oxygen and hydrogen atoms together, and hydrogen bonding
attracts water molecules, making up water.
Describe Mendel's law of independent assortment, how did he
use a dihybrid cross to provide evidence that supported his
hypothesis? Correct Answers Mendel's law of independent
assortment states that each pair of alleles segregates
independently of each other pair during gamete formation; it
only applies to genes on non-homologous chromosomes (non-
linked). He worked out this second law of inheritance by
, following two characters at the same time: seed color and seed
shape. Seeds could either be yellow or green, and round or
wrinkled. He performed a dihybrid cross with heterozygous pea
plants, which resulted in four phenotypic categories with a
9:3:3:1 ratio -- 9 yellow round, 3 green round, 3 yellow
wrinkled, and 1 green wrinkled, as predicted. These results
supported his hypothesis because the alleles for each tested gene
segregated independently from the alleles of the other genes.
Describe the role of each enzyme involved in DNA replication.
Correct Answers - The origin of replication is where the
replication of a DNA molecule begins, consisting of a specific
sequence of nucleotides.
- The replication fork is a Y-shaped region on a replicating DNA
molecule where the parental strands are being unwound and new
strands are being synthesized.
- Helicase is an enzyme that untwists the double helix of DNA at
the replication forks.
- Primase is an enzyme that joins RNA nucleotides to make a
primer during DNA replication, using the parental DNA strand
as a template.
- The primer is a short polynucleotide with a free 3' end that
contains RNA nucleotides.
- Okazaki fragments are short segments of DNA synthesized
away from the replication fork on a template strand during DNA
replication, making up the lagging strand.
- DNA polymerase III is an enzyme that adds DNA nucleotides
to the RNA primer; it can add nucleotides only to the free 3' end
of a primer or growing DNA strand.
