Cell Theory & Organelles
What are the three statements of cell theory? (must say at least 2 to get credit)
All living things are made of cells; cells are the basic unit of life; all cells come from existing cells.
Does diffusion require energy from the cell?
No. Diffusion is passive transport.
What does homeostasis mean?
Maintaining stable internal conditions.
During which phase of interphase is DNA copied?
S phase.
What is the independent variable in an experiment?
The factor the scientist changes (can control) or tests.
What important structure do eukaryotic cells have that prokaryotic cells lack?
A nucleus (and other membrane-bound organelles).
Which process moves water across a selectively permeable membrane?
Osmosis.
In which solution is solute concentration equal inside and outside a cell?
Isotonic solution.
Say the stages of mitosis in order.
Prophase → Metaphase → Anaphase → Telophase.
What does hydrophobic mean?
Repels or does not mix well with water.
Which organelle modifies and packages proteins for transport?
Golgi apparatus.
Which type of transport moves substances against their concentration gradient?
Active transport (uses ATP).
An animal cell swells in a solution. Is the solution hypotonic or hypertonic?
Hypotonic; water enters the cell.
A parent cell has 18 chromosomes. How many will each daughter cell have after mitosis?
18 chromosomes.
A student changes the amount of hours of light a plant receives and measures plant height. What is the dependent variable?
Plant height.
A cell has DNA, ribosomes, and cytoplasm but no nucleus. What type of cell is it?
Prokaryotic cell.
A white blood cell engulfs a bacterium. Name the specific transport process.
Endocytosis.
An animal cell shrivels in salty water. Explain the direction of water movement.
Water moves out of the cell toward the higher solute concentration outside.
What is apoptosis, and why is it important?
Programmed cell death; it removes unnecessary or damaged cells.
Which macromolecule is not normally used by the body for energy?
Nucleic acids.
Name four organelles or structures and explain their functions.
Possible answers:
Nucleus—protects DNA; ribosomes—make proteins; mitochondria—produce ATP; lysosomes—digest waste; cell membrane—controls passage of materials.
Name the specific transport process for each: oxygen, glucose, water, and a large particle entering a cell.
Oxygen: diffusion; glucose: facilitated diffusion; water: osmosis; large particle: endocytosis.
What type of feedback mechanism is sweating? and why?
Sweating is a negative feedback mechanism because it is stabilizes your body. When body temperature rises, sweating cools the body and helps restore normal temperature.
Explain how checkpoint failure can lead to cancer and distinguish benign from malignant tumors.
Failed checkpoints allow uncontrolled cell division. Benign tumors do not invade nearby tissues, while malignant tumors can invade and spread.
Explain why the cell membrane is selectively permeable.
Selective permeability regulates which materials enter and leave the cell, helping maintain homeostasis.