Download Biology Unit 2 Review Guide - Mattawan Consolidated School

BIOLOGY – Mr. Channell
NAME: _______________________
Biology Unit 2 Review Guide
Complete on a separate sheet of paper if needed.
1. State the 3 parts of cell theory.
Cells are the smallest unit of life…All organisms are made of cells…all cells
come from preexisting cells
2. Explain why cells need to be very small in size.
Cells are small to be more efficient at moving materials and waste in and out
3. Explain at least 3 specific differences between plant and animal cells.
Plant cells have cell walls, are rectangular in shape, have chloroplasts for
photosynthesis, and a large central vacuole
4. Explain the differences in structure (organelles present) between prokaryotic and
eukaryotic cells.
Prokaryotes do not have a nucleus, endoplasmic reticulum, or golgi
apparatus like eukaryotes do. Prokaryotes have a single stranded DNA
chromosome, while eukaryotes have many chromosomes. Prokaryotes are
generally unicellular (1 celled) organisms like bacteria, while eukaryotic cells
are generally found in multicellular (many celled) organisms like humans,
plants, or mushrooms.
5. Categorize as either a prokaryote or eukaryote: plants, animals, fungi, bacteria.
Plants, animals, and fungi are eukaryotes. Bacteria are prokaryotes.
6. Explain the function of each of the following organelles: cell membrane, cell wall,
chloroplast, cytoplasm, golgi apparatus, mitochondria, nucleus, ribosome,
vacuole, endoplasmic reticulum.
Cell membrane – separates cell from surroundings
Cell wall – extra protection for plant cells, keeps plants stiff and upright
Chloroplast – green pigment that absorbs sunlight to make food for plants
Cytoplasm – water and salt glop that organelles float in
Golgi apparatus – packages/processes material to go in/out of cell
Mitochondria – makes energy (ATP) for cell
Nucleus – cell “brain” directs activity and houses DNA
Ribosome – make proteins
Vacuole – stores water and waste products
Endoplasmic reticulum – shipping department that moves material in/out of
cell
7. Explain how the history of the mitochondria and chloroplast differs from the other
organelles and the evidence for this difference.
According to endosymbiont theory, mitochondria and chloroplasts may have
originally been free-living prokaryotes that were engulfed/absorbed by a
more complex prokaryote to form the first eukaryote ancestors. Evidence for
this includes the fact that mitochondria and chloroplasts can reproduce
without the rest of the cell.
8. Explain why some cells may have different shapes and numbers of some
organelles than others.
Different cells have different functions, and thus will be shaped differently
and have different organelle parts. A good example is comparing a skin cell
(compact and flat for protection) to a nerve cell (long and skinny to transmit
impulses).
9. Define selectively permeable.
Selectively permeable refers to a cell membrane only allowing certain
substances to move in or out of the cell.
10. Draw and label a rough diagram of the cell/plasma membrane according to the
fluid mosaic model.
11. Explain why heads and tails of the phospholipids in the membrane are arranged
like we drew them in our notes.
The heads are water loving (hydrophilic), and the tails are water hating
(hydrophobic). The reason they are arranged this way is so the heads easily
allow water and gases to pass, but not allow larger molecules to pass through
without assistance.
12. Explain the difference between active transport and passive transport.
Active transport requires energy to move substances through the bilayer
(often from low to high concentration), while passive transport requires no
energy, as substances simply flow from high to low concentrations.
13. Explain the difference between diffusion and osmosis.
Diffusion is the movement of substances from high to low concentration.
Osmosis is the movement of water from high to low concentration.
14. Give an example of diffusion.
After spraying perfume, the smell begins to spread through the room.
15. Give an example of osmosis.
Water penetrates your fingers in the bathtub, making your fingertips shrivel
up.
16. Describe how molecules move (in terms of high/low concentration levels) in both
diffusion and osmosis.
Molecules move from high to low concentrations.
17. Explain what the eventual result of diffusion is.
Equilibrium. This is a state of balance where particles are evenly spread out.
18. Explain what the eventual result of osmosis is.
This can vary depending on the situation, especially for cells. Too much
water can cause an animal cell to burst, but without enough they will shrivel.
Plant cells, however, need large amounts of water to stay rigid.
19. Describe the changes in the egg during the lab when the egg was in distilled
water vs corn syrup. Explain why these changes occurred using your knowledge
of osmosis.
In water, the egg swells, as water moves into the egg (the concentration of
water is less inside the egg than outside, so water moves into it). In syrup, the
egg shrinks, as water moves out of the egg (the concentration of water is
greater inside the egg than outside, so water moves out).
20. Be able to recognize and label parts of a plant and animal cell using a diagram.
(Note: you do not need to know the centriole or nuclear membrane)