Cell Structures
Cell Theory
Cell Types
Membrane/Transport
Photosynthesis/Respiration
100
Which organelle contains DNA in a plant or animal cell, and how does that DNA help direct cell activities?
What is the nucleus that contains DNA?
DNA provides instructions for making proteins that help the cell carry out its functions.
100
Complete this cell theory statement: New cells come from ________.
What are existing cells?
100
Which cell type lacks a membrane-bound nucleus: prokaryotic or eukaryotic?
Answer: Prokaryotic cells lack a membrane-bound nucleus.
100
What cell structure is a semipermeable barrier that controls what enters and leaves a cell?
Cell membrane. It allows some materials to cross while restricting others.
100
What TWO substances are produced by photosynthesis?
glucose and oxygen.
200
Match each structure to its function: ribosomes, endoplasmic reticulum, Golgi apparatus.
1. Sorts and packages proteins for delivery
2. Builds proteins
3. Helps process and transport proteins
1. Golgi apparatus; 2. ribosomes; 3. endoplasmic reticulum.
200
Which TWO statements are parts of cell theory?
A. All living things consist of one or more cells.
B. All cells have the same shape and job.
C. Cells are the basic structural and functional units of living things.
D. Cells form spontaneously from nonliving nutrients.
A and C. Living things contain cells, and cells are their basic units of structure and function.
200
What TWO structures occur in both prokaryotic and eukaryotic cells?
Both have ribosomes and a cell membrane.
Both also contain DNA and cytoplasm.
200
Match the term to the description.
1. Molecules move from an area of high concentration to an area of low concentration.
2. The process in which water moves from an area of high concentration to an area of low concentration.
1. Diffusion 2. Osmosis
200
Name the molecule that supplies usable energy for cell activities.
ATP
300
A leaf cell has chloroplasts, a large central vacuole, and a cell wall. Match each observation to the structure most directly responsible: makes glucose using sunlight; stores water and helps maintain pressure; provides rigid support. Explain why an animal cell would not have all three features.
Chloroplasts make glucose using light; the large central vacuole stores water and helps maintain pressure; the wall provides rigid support. Animal cells lack chloroplasts and cell walls and typically do not have a large central vacuole, although they may have smaller vacuoles.
300
How would a student determine if an organism is unicellular?
Isolate a single cell and observe if the cell is still able to carry out the functions of life.
300
This cell is a prokaryote. What evidence can be used to support this?
Circular DNA
Lacking membrane-bound organelles
300
Match each term to its description: diffusion, osmosis, active transport.
1. Movement across a membrane that requires energy and can move substances against a concentration gradient
2. Net movement of particles from higher to lower concentration
3. Net movement of water across a semipermeable membrane
1. Active transport; 2. diffusion; 3. osmosis. Diffusion and osmosis are forms of passive transport.
300
For cellular respiration that uses oxygen, name the two matter inputs and the two matter products.
Inputs: glucose and oxygen. Matter products: carbon dioxide and water
400
Muscle cells need ATP to contract. Which change would most directly reduce their ability to contract? Explain why.
A. Damage to mitochondria
B. Loss of chloroplasts
C. A thicker cell wall
D. More water in a plant’s vacuole
A. Damage to mitochondria
Damage to mitochondria can reduce ATP production, leaving less usable energy for contraction. Muscle cells are animal cells and do not contain chloroplasts or cell walls.
400
A whole bacterium consists of one cell. A whole oak tree consists of millions of cells. Classify each as unicellular or multicellular, and explain how both fit cell theory.
The bacterium is unicellular; the oak tree is multicellular. Both are made of cells. One cell carries out the bacterium’s life functions; many specialized cells work together in the tree.
400
Cell X has DNA and ribosomes but no nucleus or other membrane-bound organelles. Cell Y has a nucleus and mitochondria. Classify both cells and identify the most useful evidence.
X is prokaryotic; Y is eukaryotic. The presence or absence of a nucleus and other membrane-bound organelles is the most useful evidence. DNA and ribosomes occur in both types.
400
A membrane model bag contains starch and glucose and is placed in water containing neither. After 20 minutes, glucose is detected outside, but starch is not. Which conclusion is supported, and why?
A. The membrane blocks every substance.
B. The membrane allows some substances to cross but restricts others.
C. Glucose was changed into starch.
D. Every living membrane behaves exactly like this bag.
B. The membrane allows some substances to cross but restricts others.
Glucose crossed detectably, while starch did not under the test conditions. The result supports selective permeability in this model. It does not show that every living membrane behaves exactly like the bag.
400
How can one plant help cycle matter through both processes?
A plant performs photosynthesis and cellular respiration. The products of one process can become the inputs of the other.
500
A written cell model says, “The nucleus builds proteins, ribosomes package them, and the Golgi apparatus provides ATP.” A cell has DNA instructions, but newly made proteins collect in its endoplasmic reticulum instead of reaching the membrane. Correct the three errors. Use this evidence to identify a likely delivery problem and explain how it could disrupt homeostasis.
The nucleus stores DNA instructions; ribosomes build proteins; the Golgi apparatus modifies, sorts, and packages proteins. Mitochondria help produce ATP. The buildup suggests a problem moving proteins from the ER to the Golgi or through the Golgi delivery pathway, without identifying one organelle with certainty. Fewer membrane proteins could disrupt nutrient, waste, or ion transport and stable internal conditions. Accept other delivery problems supported by the evidence.
500
A student observes skin cells dividing to produce new cells during wound healing. Which statement does this evidence support most directly? Explain your choice.
A. Every cell has a cell wall.
B. New cells come from existing cells.
C. All cells perform identical jobs.
D. Nutrients turn directly into new cells.
B. New cells come from existing cells.
The observed new cells came from cells that were already present. This directly supports that claim; it does not demonstrate every claim of cell theory by itself.
500
A chart comparing prokaryotes and eukaryotes lists “nucleus” under BOTH cell types and “cell membrane” under EUKARYOTIC ONLY. Correct both entries. Then explain why “one cell” should not be placed under PROKARYOTIC ONLY.
Move nucleus to eukaryotic only and membrane to both. Some eukaryotes, including yeast and amoebas, are unicellular. Cell number alone does not distinguish the two cell types.
500
An animal cell is placed in a solution with more noncrossing solute than its cytoplasm. Will water move into or out of the cell overall? Will the cell swell or shrink? Identify the surrounding solution as hypotonic, isotonic, or hypertonic.
Water moves out overall, and the cell shrinks. The solution is hypertonic relative to the cell. Net water movement is toward the higher concentration of solute that cannot cross the membrane.
500
A student says carbon disappears when glucose is broken down. How would you correct this claim?
Carbon does not disappear. During cellular respiration, carbon atoms from glucose become part of carbon dioxide molecules.