Living Things & Cell Basics
What is the smallest unit of life?
A cell
Which type of cell does NOT have a nucleus?
Prokaryotic cell
Which organelle stores DNA and controls cell activities?
Nucleus
What is the main job of the cell membrane?
Controls what enters and leaves the cell
What type of transport does not require energy?
Passive transport
What does the word biotic mean?
Living/Organic
What type of cell is a bacterium?
Prokaryotic cell
Which organelle powers the cell using cellular respiration to produce ATP?
Mitochondria
What type of molecule makes up the two layers of the cell membrane?
Phospholipids
A cell uses ATP to move a substance from low concentration to high concentration. What type of transport is this?
Active transport
What is homeostasis?
Maintaining a stable internal balance.
Which type of cell is usually larger and more complex?
Eukaryotic cell
Which organelle makes proteins?
Ribosomes
Which part of a phospholipid loves water?
Head (hydrophilic)
In diffusion, molecules move from an area of ______ concentration to ______ concentration.
High to low
According to cell theory, where do all new cells come from?
Other, preexisting cells
Name one structure found in plant cells but not animal cells.
Cell wall, chloroplast, or large central vacuole
Which organelle contains digestive enzymes that break down waste and old cell parts?
Lysosome
What does selectively permeable mean?
Some substances can cross the membrane while others cannot.
What is facilitated diffusion?
Movement of substances across a membrane with help from transport proteins, without using energy.
Name the 7 characteristics that all living things share.
1. made of cells
2. reproduce
3. use energy
4. respond to stimuli
5. maintain homeostasis
6. display heredity
7. evolve and adapt
A scientist finds a single-celled organism with DNA inside a nucleus. Is it a prokaryote or eukaryote? Explain.
Eukaryote, because it has a nucleus.
A cell needs to produce and transport large amounts of proteins. Which organelle is responsible for this process?
Rough Endoplasmic Reticulum
Why do the fatty acid tails of phospholipids point inward, away from water?
They are hydrophobic, meaning they avoid water.
What is the difference between endocytosis and exocytosis?
Endocytosis brings materials into the cell, while exocytosis moves materials out of the cell. Both require energy.