Characteristics
All living things are made up of one or more of these.
cells
What is the smallest unit of life?
Cell
Which organelle acts like the “brain” of the cell by storing DNA?
Nucleus
Which organelles produce ATP for energy?
Mitochondria
What do both plant and animal cells use to control what enters or leaves the cell?
Cell membrane
Living things must obtain and use this to carry out life processes.
energy!
Which type of cell is simpler in structure and smaller in size
prokaryotic cells
What is the function of the vacuole?
store water, nutrients, and waste
Which organelle makes energy from sunlight in plant cells?
chloroplasts
2 organelles the plants cells have that animals do not.
cell wall, chloroplasts
Name 3 characteristics of living things
1. grow
2. need energy
3. made up of cells
4. produce waste that must be removed
5. respond to stimuli
6. reproduce
What kind of cells have membrane-bound organelles?
Eukaryotic cells. (plants, animals, fungi...)
Which organelle works closely with the rough ER to modify and package proteins?
Golgi body
Which part of the cell is responsible for breaking down waste and worn-out cell parts?
Lysosomes
What green pigment inside chloroplasts captures sunlight?
Chlorophyll
Why is a virus often considered not truly alive according to the characteristics of living things?
Because it cannot reproduce or carry out metabolism without a host cell.
Describe one theory that explains how eukaryotic cells evolved from prokaryotic ancestors.
The endosymbiotic theory — larger prokaryotes engulfed smaller ones that became organelles like mitochondria or chloroplasts.
What network of membranes helps move materials around the cell, often connected to the nucleus?
Endoplasmic Reticulum
Why does a muscle cell contain more mitochondria than a skin cell?
Because muscle cells require more energy for contraction and movement.
Why do plant cells not need lysosomes like animal cells do?
Plant cells rely on vacuoles and enzymes for waste breakdown and have less need for lysosomes
Give 2 examples of an external stimuli and 2 examples of internal stimuli. How do these contribute to an organism's survival?
answers can vary...
What evolutionary advantage might eukaryotic cells have gained from developing membrane-bound organelles?
They can compartmentalize functions, increasing efficiency and complexity.
What would likely happen to a cell if its ribosomes stopped functioning? Describe in detail
It would be unable to produce proteins, halting growth and repair processes.
How does energy use differ between producers and consumers? Explain in detail.
Produces make their own energy (via photosynthesis or chemosynthesis), while consumers consume other organisms for energy.
Compare and contrast photosynthesis and respiration. What organelles use these reactions?
Mitochondria use respiration: glucose + oxygen = carbon dioxide + water + energy
Chloroplasts use photosynthesis: energy (from sun) + carbon dioxide + water = glucose + oxygen
The reactions are opposite of each other