BIOLOGY 189 MAIN EXAMS ALL 2025/2026 QUESTIONS
AND SOLUTIONS GRADED A+ TIP
✔✔Telophase - ✔✔Nuclear envelope and nucleolus form at each pole. Chromosomes
decondense. Spindle disappears.
✔✔Cytokinesis - ✔✔division of the cytoplasm to form two separate daughter cells
✔✔How do proteins know where to begin DNA replication in the genome? - ✔✔origin of
replication
✔✔What proteins are involved in DNA replication and what are there specific functions?
- ✔✔-Helicase helps unwind and unzips DNA
-DNA polymerase assembles and proofreads new DNA strands.
✔✔process of binary fission - ✔✔1. parent cell contains one chromosome
2. DNA replicates and attaches to cell membrane.
3. Membrane growth between the two attachment points, moves the DNA molecules
apart as new cell wall material is deposited.
4. Two daughter cells, each identical to the original
✔✔Explain the different types of horizontal transfer to me. - ✔✔1. Transformation-get it
from the outside
2. Transduction- virus brings it to the bacteria
3. conjunction- get it from another bacteria
✔✔Why does horizontal transfer contributed to genetic diversity? - ✔✔In order to
survive in new environments and to evolve throughout the years
✔✔What is the difference between chromatin and chromosomes? - ✔✔Chromatin
means that DNA is wrapped around histone proteins loosely, opposed to chromosomes
who are highly condensed chromatin
✔✔How do these relate to the different stages of the cell cycle? - ✔✔The cell must have
access to the information in the DNA. Also, a dividing cell must package its DNA into a
portable form that can easily move into the two daughter cells.
✔✔What are homologous chromosomes? - ✔✔Two genetically similar chromosomes
with different alleles(traits)
✔✔What is a centromere? - ✔✔A small section of DNA and associated proteins that
attaches the two sister chromatids
, ✔✔What are sister chromatids? - ✔✔2 identical copies of DNA (chromatin) held
together by a centromere
✔✔When do sister chromatids exist during the cell cycle? - ✔✔During the prophase and
metaphase
✔✔When do sister chromatids go away? - ✔✔During anaphase
✔✔When do the daughter chromosomes first exist in the cell cycle? - ✔✔During
telaphase
✔✔Walk me through the different stages of interphase. What happens during each
stage of interphase. - ✔✔G1 Phase-normal cell function and cell growth
S Phase- DNA replication
G2 Phase- additional growth and prepares to divide
✔✔What is a centrosome? - ✔✔where microtubules are synthesized and organized
✔✔How do centrosome relate to the cell cycle at each stage? - ✔✔It coordinates the
movements of the chromosomes during mitosis
✔✔What is a kinetochore? - ✔✔A structure of proteins attached to the centromere that
links each sister chromatid to the mitotic spindle.
✔✔What are microtubules? - ✔✔maintenance of cell shape, movement of organelles,
cell mobility
✔✔When in the cell cycle are microtubules critical to function?Why? - ✔✔When the
microtubules attache to the sister chromatids, it helps them break apart during the
anaphase stage and helps the chromosomes align along the equator of cell.
✔✔What are microfilaments? - ✔✔Microfilaments are responsible for any movement
that the cell makes
✔✔When in the cell cycle are microfilaments critical to function?why? - ✔✔They are
critical in the telophase, when the cell needs to break apart to form two new cells .
✔✔Compare and contrast cytokineses in an animal cell versus plant cell. - ✔✔In an
animal plant , the somatic cells only need to create a cell membrane while plant animals
need a cell wall too.
✔✔Why are there checkpoints in the cell cycle? - ✔✔To check for errors prior to moving
forward to another stage
AND SOLUTIONS GRADED A+ TIP
✔✔Telophase - ✔✔Nuclear envelope and nucleolus form at each pole. Chromosomes
decondense. Spindle disappears.
✔✔Cytokinesis - ✔✔division of the cytoplasm to form two separate daughter cells
✔✔How do proteins know where to begin DNA replication in the genome? - ✔✔origin of
replication
✔✔What proteins are involved in DNA replication and what are there specific functions?
- ✔✔-Helicase helps unwind and unzips DNA
-DNA polymerase assembles and proofreads new DNA strands.
✔✔process of binary fission - ✔✔1. parent cell contains one chromosome
2. DNA replicates and attaches to cell membrane.
3. Membrane growth between the two attachment points, moves the DNA molecules
apart as new cell wall material is deposited.
4. Two daughter cells, each identical to the original
✔✔Explain the different types of horizontal transfer to me. - ✔✔1. Transformation-get it
from the outside
2. Transduction- virus brings it to the bacteria
3. conjunction- get it from another bacteria
✔✔Why does horizontal transfer contributed to genetic diversity? - ✔✔In order to
survive in new environments and to evolve throughout the years
✔✔What is the difference between chromatin and chromosomes? - ✔✔Chromatin
means that DNA is wrapped around histone proteins loosely, opposed to chromosomes
who are highly condensed chromatin
✔✔How do these relate to the different stages of the cell cycle? - ✔✔The cell must have
access to the information in the DNA. Also, a dividing cell must package its DNA into a
portable form that can easily move into the two daughter cells.
✔✔What are homologous chromosomes? - ✔✔Two genetically similar chromosomes
with different alleles(traits)
✔✔What is a centromere? - ✔✔A small section of DNA and associated proteins that
attaches the two sister chromatids
, ✔✔What are sister chromatids? - ✔✔2 identical copies of DNA (chromatin) held
together by a centromere
✔✔When do sister chromatids exist during the cell cycle? - ✔✔During the prophase and
metaphase
✔✔When do sister chromatids go away? - ✔✔During anaphase
✔✔When do the daughter chromosomes first exist in the cell cycle? - ✔✔During
telaphase
✔✔Walk me through the different stages of interphase. What happens during each
stage of interphase. - ✔✔G1 Phase-normal cell function and cell growth
S Phase- DNA replication
G2 Phase- additional growth and prepares to divide
✔✔What is a centrosome? - ✔✔where microtubules are synthesized and organized
✔✔How do centrosome relate to the cell cycle at each stage? - ✔✔It coordinates the
movements of the chromosomes during mitosis
✔✔What is a kinetochore? - ✔✔A structure of proteins attached to the centromere that
links each sister chromatid to the mitotic spindle.
✔✔What are microtubules? - ✔✔maintenance of cell shape, movement of organelles,
cell mobility
✔✔When in the cell cycle are microtubules critical to function?Why? - ✔✔When the
microtubules attache to the sister chromatids, it helps them break apart during the
anaphase stage and helps the chromosomes align along the equator of cell.
✔✔What are microfilaments? - ✔✔Microfilaments are responsible for any movement
that the cell makes
✔✔When in the cell cycle are microfilaments critical to function?why? - ✔✔They are
critical in the telophase, when the cell needs to break apart to form two new cells .
✔✔Compare and contrast cytokineses in an animal cell versus plant cell. - ✔✔In an
animal plant , the somatic cells only need to create a cell membrane while plant animals
need a cell wall too.
✔✔Why are there checkpoints in the cell cycle? - ✔✔To check for errors prior to moving
forward to another stage
