BIOL 121 Exam 4 Questions With Complete Solutions
After an egg is fertilized by a sperm, which process of cell
division leads to the development of the embryo? Correct
Answers Through repeated rounds of cell division, the original
zygote cell is duplicated, eventually forming an embryo.
As it was being constructed, a coding region of a strand of
mRNA was mis-transcribed as GAU instead of GAC. What kind
of mutation is this? Correct Answers nucleotide polymorphism
Describe what happens during the stages of mitosis. (Do not
worry about the actual names of the phases) Correct Answers
Early interphase: During interphase, the chromosomes are
decondensed and loosely arranged in the nucleus. Each
chromosome exists as a single very long, very thin piece of
DNA with associated proteins. During this time, the cell carries
out its normal activities. Chromosomes
Duplicate: As the cell prepares to divide, each chromosome is
duplicated. By the end of interphase, ever chromosome in the
nucleus has a duplicate, called a sister chromatid, attached to it
at a structure called the centromere. The chromosomes are still
uncondensed and so are not visible under a microscope.
Chromosomes
Condense: The first stage of mitosis is called prophase. It begins
when the nuclear membrane dissolves. The duplicated
chromosomes become visible in the microscope as they
condense (with the help of proteins) into tightly wound, thick,
dense structures. The cell start to lay down protein tracks (called
, the mitotic spindle, shown as yellow lines in the center view but
omitted from the left view) onto which the chromosomes can be
organized.
Chromosomes Align: During the next stage, metaphase, the
duplicated chromosomes (pairs of sister chromatids attached at a
centromere) line up in the center of the cell, with each
chromosome attached to a separate track of the mitotic spindle.
Chromosomes Split: During anaphase, the sister chromatids split
apart and the mitotic spindle retracts. As the tracks of the spindle
retreat toward opposite ends of the cell, one chromatid from
each pair of sister chromatids is dragged along with each track.
Nucleus Reforms: After the mitotic spindle is fully retracted,
and each set of chromosomes is at one end of the cell, the
nuclear membrane begins to re-form. The chromosomes
uncondense. By the end of this last stage, called telophase, the
nucleus has been duplicated into two nuclei, each with a full
Fossil fuels (like oil, coal, natural gas) ultimately came from
where? Correct Answers Fossil fuels ultimately come from
sunlight energy captured and stored by plants and plankton
through photosynthesis.
How many mRNA nucleotides code for a single amino acid?
Correct Answers Each group of three nucleotides encodes one
amino acid.
How many total copies of a given chromosome does a human
somatic cell contain after chromosome duplication and just
After an egg is fertilized by a sperm, which process of cell
division leads to the development of the embryo? Correct
Answers Through repeated rounds of cell division, the original
zygote cell is duplicated, eventually forming an embryo.
As it was being constructed, a coding region of a strand of
mRNA was mis-transcribed as GAU instead of GAC. What kind
of mutation is this? Correct Answers nucleotide polymorphism
Describe what happens during the stages of mitosis. (Do not
worry about the actual names of the phases) Correct Answers
Early interphase: During interphase, the chromosomes are
decondensed and loosely arranged in the nucleus. Each
chromosome exists as a single very long, very thin piece of
DNA with associated proteins. During this time, the cell carries
out its normal activities. Chromosomes
Duplicate: As the cell prepares to divide, each chromosome is
duplicated. By the end of interphase, ever chromosome in the
nucleus has a duplicate, called a sister chromatid, attached to it
at a structure called the centromere. The chromosomes are still
uncondensed and so are not visible under a microscope.
Chromosomes
Condense: The first stage of mitosis is called prophase. It begins
when the nuclear membrane dissolves. The duplicated
chromosomes become visible in the microscope as they
condense (with the help of proteins) into tightly wound, thick,
dense structures. The cell start to lay down protein tracks (called
, the mitotic spindle, shown as yellow lines in the center view but
omitted from the left view) onto which the chromosomes can be
organized.
Chromosomes Align: During the next stage, metaphase, the
duplicated chromosomes (pairs of sister chromatids attached at a
centromere) line up in the center of the cell, with each
chromosome attached to a separate track of the mitotic spindle.
Chromosomes Split: During anaphase, the sister chromatids split
apart and the mitotic spindle retracts. As the tracks of the spindle
retreat toward opposite ends of the cell, one chromatid from
each pair of sister chromatids is dragged along with each track.
Nucleus Reforms: After the mitotic spindle is fully retracted,
and each set of chromosomes is at one end of the cell, the
nuclear membrane begins to re-form. The chromosomes
uncondense. By the end of this last stage, called telophase, the
nucleus has been duplicated into two nuclei, each with a full
Fossil fuels (like oil, coal, natural gas) ultimately came from
where? Correct Answers Fossil fuels ultimately come from
sunlight energy captured and stored by plants and plankton
through photosynthesis.
How many mRNA nucleotides code for a single amino acid?
Correct Answers Each group of three nucleotides encodes one
amino acid.
How many total copies of a given chromosome does a human
somatic cell contain after chromosome duplication and just
