Model Growth and Repair Processes - Biology

Which checkpoint ensures chromosomes are properly attached to spindle fibers before separation?

Metaphase (spindle) checkpoint. Prevents premature separation that would cause chromosome loss.
Which feedback mechanism typically stabilizes internal conditions during tissue repair?

Negative feedback. Counteracts deviations to maintain optimal repair conditions.
Which model best explains why multicellular organisms need specialized transport systems?

Diffusion alone is too slow over long distances. Large organisms require active transport to overcome diffusion limits.
Identify the stage: Chromosomes are lined up single-file at the equator with spindle attachment.

Metaphase. Chromosomes aligned at center with proper spindle attachment.
What is a chromatid?

One of two identical copies of a replicated chromosome. DNA replication creates two attached copies for accurate distribution.
Which cell cycle phase is primarily cell growth and normal cell function before DNA synthesis?

G $1$ phase. Cell accumulates materials and energy needed for DNA replication.
Which immune cells help clean debris and coordinate later stages of tissue repair?

Macrophages. Remove debris and release signals for tissue reconstruction.
What is an organ in biological organization models?

Structure made of multiple tissues performing specific functions. Higher organization level combining different tissue types.
Which model-based prediction is correct: If spindle fibers fail to attach, what checkpoint stops division?

Metaphase (spindle) checkpoint. Prevents unequal chromosome distribution during cell division.
Identify the best model-based explanation: Why does a cut heal by mitosis in nearby skin cells?

Mitosis replaces lost cells with genetically identical cells. Preserves tissue function by replacing damaged cells exactly.
Which mitosis stage aligns chromosomes at the cell equator (metaphase plate)?

Metaphase. Ensures equal chromosome distribution by central alignment.
Which cell cycle phase replicates DNA to prepare for cell division?

S phase. DNA must be duplicated before cell division to maintain chromosome number.
What is a stem cell?

An undifferentiated cell that can self-renew and differentiate. Can produce both new stem cells and specialized cell types.
What structure holds sister chromatids together before anaphase?

Centromere (with cohesin proteins). Keeps sister chromatids attached until proper spindle alignment.
How does apoptosis support growth and repair in organisms?

Eliminates damaged cells to protect tissue function. Prevents defective cells from interfering with normal tissue function.
What is the main purpose of mitosis in multicellular organisms?

Growth and tissue repair by making identical cells. Creates new cells to replace damaged ones and increase organism size.
Identify the stage: Sister chromatids are moving toward opposite ends of the cell.

Anaphase. Active separation phase moving chromatids to opposite poles.
Which stem cells are found in adult tissues and mainly maintain and repair those tissues?

Adult (somatic) stem cells. Limited to specific tissue types but essential for local repair.
What is the correct order of the stages of the cell cycle?

G $1$ → S → G $2$ → M. Sequential phases where cells grow, replicate DNA, check quality, then divide.
What is a simple model-based definition of wound healing?

Coordinated repair involving clotting, inflammation, and tissue rebuilding. Sequential processes restore tissue integrity and function.
What is the direct relationship in the surface area-to-volume ratio model as size increases?

Surface area-to-volume ratio decreases. Geometric constraint that limits organism size without adaptations.
What is homeostasis in the context of growth and repair models?

Maintenance of stable internal conditions. Required for coordinated growth and effective repair responses.
Which model-based conclusion is most accurate: Uncontrolled mitosis due to checkpoint failure leads to what?

Cancer (tumor formation). Loss of growth control leads to abnormal cell proliferation.
Identify the correct model outcome: If DNA damage is detected at G $1$ , what should happen to the cell cycle?

Cell cycle arrest for repair or apoptosis. Checkpoints prevent division of damaged cells.
Which checkpoint verifies cell size, nutrients, and DNA damage before DNA replication?

G $1$ checkpoint. Ensures cell readiness before committing to DNA replication.
Which type of cell division produces two genetically identical daughter cells for growth and repair?

Mitosis. Unlike meiosis, mitosis preserves chromosome number and genetic content.
What is a tissue in biological organization models?

Group of similar cells working together for a function. Basic structural unit formed by cellular specialization.
What is the spindle apparatus?

Microtubule system that separates chromosomes. Protein fibers that attach to and move chromosomes during division.
Which mitosis stage reforms nuclear envelopes and begins chromosome decondensation?

Telophase. Nuclear membranes reform around separated chromosome sets.
What is apoptosis?

Programmed cell death that removes damaged cells. Controlled cell death prevents damaged cells from becoming harmful.
Which cell adaptation increases surface area for exchange to support growth and repair needs?

Membrane folding (for example, microvilli). Structural modifications overcome surface area limitations.
What is the key genetic idea in models of differentiation in multicellular organisms?

Same DNA, different gene expression patterns. Different cell types result from activating different gene sets.
Which type of stem cell can differentiate into nearly any body cell type?

Pluripotent stem cell. Has broad developmental potential except extraembryonic tissues.
Which cell structure forms spindle fibers that move chromosomes during mitosis?

Centrosome (microtubule-organizing center). Organizes microtubules that physically move chromosomes during division.
Which immune cells are typically first to arrive at a wound to reduce infection risk?

Neutrophils. Rapid responders that combat infection in damaged tissue.
Which mitosis stage has chromosomes condensing and the nuclear envelope breaking down?

Prophase. Chromosomes become visible and nuclear barrier dissolves for division.
Identify the correct model outcome: If nutrient supply drops, what happens to mitosis rate in tissues?

Mitosis rate generally decreases. Limited resources slow cell division and growth processes.
What is the function of fibrin in a wound-healing model?

Forms a mesh that stabilizes the blood clot. Protein network that strengthens and stabilizes blood clots.
What is angiogenesis in a tissue repair model?

Formation of new blood vessels to supply healing tissue. Restores blood supply needed for tissue regeneration.
What is cytokinesis?

Division of the cytoplasm into two cells. Completes cell division by physically separating the two nuclei.
What is an organ system in biological organization models?

Group of organs working together to perform major functions. Highest level of functional organization in multicellular organisms.
Which mitosis stage separates sister chromatids and pulls them to opposite poles?

Anaphase. Sister chromatids separate to ensure equal genetic distribution.
What is the direct formula for population growth in a simple exponential model?

$N(t)=N_0e^{rt}$ . Mathematical model for unlimited population growth over time.
What is differentiation?

Process by which cells become specialized in structure and function. Cells acquire specific roles through selective gene expression changes.
What is the M phase of the cell cycle composed of?

Mitosis and cytokinesis. Nuclear division followed by cytoplasmic division creates two cells.
Which checkpoint verifies DNA replication is complete and damage is repaired before mitosis?

G $2$ checkpoint. Confirms DNA integrity before proceeding to chromosome separation.
Which option best completes the model: Mitosis makes identical cells, while meiosis makes _____?

Genetically varied gametes with half the chromosome number. Meiosis reduces chromosome number and introduces genetic variation.
Which cell cycle phase checks DNA replication and prepares the cell for mitosis?

G $2$ phase. Quality control ensures accurate DNA replication before division begins.
Which model explains why small organisms can exchange materials without a circulatory system?

Diffusion over short distances is sufficient. Short distances allow direct molecular exchange without transport systems.
Identify the stage: Two nuclei are forming and chromosomes are decondensing.

Telophase. Final stage reforming nuclei around separated chromosome sets.
Which surface area-to-volume model predicts slower diffusion as an organism grows larger?

Volume increases faster than surface area as size increases. Mathematical relationship explaining size limitations in biology.
Which cells produce collagen to rebuild connective tissue during repair?

Fibroblasts. Synthesize structural proteins to restore tissue strength.
What is a scar in a repair model?

Fibrous tissue that replaces normal tissue after major damage. Fibrous replacement when original tissue cannot be fully restored.
Which blood component is most directly responsible for initial clot formation after injury?

Platelets. Cell fragments that aggregate and initiate clotting cascade.

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