Little Bit of Everything
A cancer treatment works by triggering apoptosis in rapidly dividing cells.
Why is this effective?
A. Cancer cells divide faster than most normal cells
B. Cancer cells contain different DNA
C. Cancer cells lack mitochondria
D. Cancer cells do not replicate DNA
A. Cancer cells divide faster than most normal cells, and apoptosis kills the cells quickly
1. What is the primary purpose of mitosis?
A. To produce gametes
B. To create genetically identical cells
C. To reduce chromosome number
D. To increase genetic variation
B. To create genetically identical cells
Divide one cell, into two -- makes identical copy = No genetic variation
BONUS - what is the name of process that does cause genetic variation
All cells in a multicellular organism generally contain —
A. Different DNA
B. Identical DNA
C. No DNA
D. Only RNA
B — Identical DNA
Nearly all somatic cells in an organism contain identical DNA.
Differences arise from gene expression, not different DNA.
Cancer is best described as —
A. Controlled cell division
B. Rapid and uncontrolled cell division
C. Lack of mitosis
D. Cell specialization
B — Rapid and uncontrolled cell division
Cancer results from failure of cell cycle regulation.
It is the opposite of controlled division.
Which phase of the cell cycle involves cell growth and normal metabolic activity?
A. M phase
B. Interphase
C. Cytokinesis
D. Prophase
B - Interphase
Interphase (G₁, S, G₂) is when the cell grows, performs normal functions, and replicates DNA.
A, C, D are stages within Mitosis phase, not the primary growth stage.
A scientist discovers a mutation in a gene responsible for repairing DNA errors.
Why does this increase cancer risk?
A. DNA replication stops
B. Mutations accumulate in important regulatory genes
C. Cells become specialized too quickly
D. Chromosomes double in number
B — Mutations accumulate in important regulatory genes
9. Mitosis is most directly responsible for —
A. Genetic variation
B. Growth and tissue repair
C. Formation of gametes
D. Reduction of chromosome number
B. Growth and tissue repair
Ex. paper cut, closing quick with new skin cells only at the site of cut
Cell differentiation results in cells that —
A. Have identical functions
B. Perform specialized functions
C. Divide continuously
D. Contain different DNA
B. Perform specialized functions
Differentiation results in specialized structure and function.
All cells maintain the same DNA (so D is incorrect).
A mutation in a gene that regulates the cell cycle is most likely to result in —
A. Faster DNA replication accuracy
B. Uncontrolled cell division
C. Cell differentiation
D. Increased checkpoints
B — Uncontrolled cell division
Mutations in regulatory genes (e.g., tumor suppressor genes) remove cell cycle control.
A and D would prevent cancer, not cause it.
DNA replication occurs during which phase?
A. G₁
B. S
C. G₂
D. M
B. S
DNA replication occurs during the S (Synthesis) phase of interphase.
G₁ is growth.
G₂ prepares for mitosis.
M phase is division.
A tumor sample shows cells dividing even with severe DNA damage.
Which process is most likely not functioning correctly?
A. DNA transcription
B. Cell cycle checkpoints
C. Protein synthesis
D. Photosynthesis
B — Cell cycle checkpoints
because the "police" of cycle has not stopped to repair damage before generating more - they are not doing their job of "checking" DNA for mistakes before being replicated
What is the main purpose of mitosis?
A. Produce gametes
B. Repair DNA
C. Create two identical daughter cells
D. Reduce chromosome number
C — Create two identical daughter cells
Mitosis ensures genetic continuity by producing two genetically identical cells.
A describes meiosis.
B is not the main purpose of mitosis.
D describes meiosis.
What causes cells with identical DNA to become different types of cells?
A. Loss of chromosomes
B. Different genes being expressed
C. Different numbers of mitochondria
D. DNA mutations
B — Different genes being expressed
Cell differentiation is driven by selective gene expression.
Cells do not lose chromosomes (A) or require mutation (D) to specialize.
If DNA replication errors are not corrected before mitosis, what is the most likely outcome?
A. Faster cell growth
B. Genetic mutations passed to daughter cells
C. Immediate cell death
D. Increased protein production
B — Genetic mutations passed to daughter cells
Uncorrected replication errors become mutations that are inherited by daughter cells.
A and D do not logically result from replication errors.
C is possible but not the most likely outcome.
During which stage of mitosis do chromosomes line up at the cell’s equator?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
B — Metaphase
During metaphase, chromosomes align at the cell’s equator (metaphase plate).
Prophase = chromosomes condense.
Anaphase = chromatids separate.
Telophase = nuclei reform.
A group of cells fails to specialize properly during development. As a result, tissues do not form correctly.
Which process most likely failed?
A. DNA replication
B. Cytokinesis
C. Gene regulation
D. Mitosis only
C — Gene regulation
Why is DNA replication necessary before mitosis?
A. To reduce chromosome number
B. To increase cell size
C. To ensure genetic continuity
D. To produce ATP
C — To ensure genetic continuity
Replication ensures each daughter cell receives identical genetic information.
Which is the best example of a specialized cell?
Stem cell
B.Skin cells
C. Red blood cell
D. Fertilized egg
Red blood cell
Rationale:
A red blood cell is fully differentiated and specialized.
Stem cells and skin cells are unspecialized.
Which best explains why the cell cycle includes checkpoints?
A. To increase mutation rates
B. To ensure proper division and prevent errors
C. To speed up mitosis
D. To reduce ATP production
B — To ensure proper division and prevent errors
Checkpoints regulate progression and prevent damaged DNA from dividing.
A is incorrect (cells avoid mutations).
C and D are unrelated.
6. Cytokinesis results in —
A. DNA replication
B. Division of the nucleus
C. Division of the cytoplasm
D. Chromosome duplication
C. Division of the cytoplasm
ending of cycle - when one cells successfully splits into two identical cells due to division
A scientist removes the nucleus from a skin cell and places it into an egg cell whose nucleus was removed. The egg develops into a normal organism.
What does this demonstrate?
A. Skin cells contain different DNA than egg cells
B. All somatic cells contain the same DNA
C. Differentiated cells cannot divide
D. Only stem cells contain full genetic information
B — All somatic cells contain the same DNA
somatic = body
Why are stem cells important in development?
A. They contain no DNA
B. They can differentiate into multiple cell types
C. They divide only once
D. They prevent mutations
B — They can differentiate into multiple cell types
Stem cells are undifferentiated and capable of specialization.
They do contain DNA and divide multiple times.
Environmental factors can influence cell differentiation by —
A. Changing the organism’s species
B. Destroying DNA completely
C. Affecting gene expression
D. Stopping mitosis permanently
C — Affecting gene expression
Environmental factors influence which genes are activated or silenced.
They do not change species (A) or destroy DNA completely (B).
Which situation would most likely lead to cancer development?
A. Proper checkpoint function
B. DNA repair mechanisms working correctly
C. Failure of cell cycle checkpoints
D. Controlled apoptosis
C — Failure of cell cycle checkpoints
Cancer develops when checkpoints fail and damaged cells continue dividing.
A, B, and D represent normal protective mechanisms.
A cell detects DNA damage during the G₁ checkpoint. The damage cannot be repaired.
What will most likely occur?
A. The cell continues to divide
B. The cell enters apoptosis
C. The cell skips S phase
D. The cell increases ATP production
B — The cell enters apoptosis