Name: ______________________________ Date: _________________
Biology Midterm Study Guide
1) What are 3 differences between a prokaryote and eukaryote? Identify 3 similarities
between prokaryotes and eukaryotes. Give examples of each cell type.
Prokaryotes
Both
Eukaryotes
Simpler, no nucleus, only ribosomes
Example: bacteria
More complex, nucleus, many organelles
Example: Animal Cells &
Plant Cells
“Euks have Nukes but Prokes have no Yolks”
2)
Cell Membrane, Cytoplasm,
DNA, ribosomes
What are 3 differences between plant and animal cell types?
Plant Cells
Animal Cells
Box-shaped, green, chloroplasts for photosynthesis
Cell wall, Large Central Vacuole
Spherical, centrioles, small vacuoles
3)
Identify the function of:
a. Cell Membrane:
Controls what enters & leaves cell
b. Vacuole:
Stores food, water, waste
c. Lysosome:
Has enzymes for digesting/recycling mtrls in cell
d. Mitochondrion (Mitochondria): Makes energy for all Euk cells
e. Golgi apparatus:
Packages & transport proteins & lipids in vesicles
f. Endoplasmic Reticulum: Moves proteins and lipids to Golgi
g. Chloroplast:
Makes glucose (food) from sunlight (in plants only)
h. Ribosome:
Makes proteins in all cells (Euks & Proks)
4)
What is pH? Acids? Bases? Neutral?
pH: “Power of Hydrogen” = acidity of a solution [the amont of hydrogen+ ions]
Acid:
ph of 6-1
[more H+ ions]
Base:
pH of 8-14
[less H+ ions]
Neutral:
pH of 7
[balance of H+ and OH- ions]
5)
How do enzymes and catalysts work? What is their role in the cell?
What they do: Enzymes “catalyze” – speed up – most chemical reactions in living things.
How:
- Because of their specific shapes, “enzymes” fit only a few molecules, bringing
together/or breaking apart “substrates” (the reactants) that fit by binding them at their
“active sites”; this lowers activation energy, and allows new products to be formed more
quickly.
6)
Enzymes work well under certain conditions (ex. Temperature, pH). Explain.
Extreme temp & pH causes enzymes to lose their shape/active sites, slowing/stopping
them from catalyzing chem reactions.
7) Place the following in correct order: Biosphere, community, organism, ecosystem,
tissue, cell [Small to large: cell, tissue, organism, comm’ty, ecosyst., Biosphere]
8) List and describe the properties of water including adhesion, cohesion, hydrogen
and covalent bonding. Why does ice float?
- Why it FLOATS (in LIQUID water): Water expands when it freezes, becoming less dense
- Hydrogen Bonding: Molecules with “+” H atoms bond with molecules with other “-“ atoms.
- Cohesion: Polar molecules (like water) sticks to itself because of Hydrogen bonds
- Adhesion: Polar molecules (like water) stick to other polar molecules.
- Covalent Bonding: Bond formed by sharing of electrons.
9) Identify the 4 organic (carbon-based) biological macromolecules. Provide the building
blocks (monomers) that make up these 4 macromolecules (polymers).
Carbon-Based Macromolecules (polymers)
i. Carbohydrates
ii. Proteins
iii. Nucleic Acids
iv. Lipids (not polymers)
Building blocks (monomers)
i. glucose
ii. amino acids
iii. Nucleotides (ATC&G)
iv. None
10) Give examples of each of the 4 types of organic (carbon-based) biological macromolecules.
(ex. Carbohydrate: polysaccharide)
Carbon-Based Macromolecules (polymers)
i. Carbohydrates
ii. Proteins
iii. Nucleic Acids
Examples
i. starch & cellulose
ii. hemoglobin & enzymes
iii. DNA and RNA
11) Describe the sequence that correctly traces the path of protein synthesis (manufacture) from nucleus to release from the cell.
i. Nucleus (where instructions originate/come from - DNA)
ii. Rough Endoplasmic Reticulum – ER – (where ribosomes make proteins)
iii. Golgi (where proteins are modified and packaged)
iv. A vesicle (in which proteins travel to their final destination)
12) Define and Describe: Osmosis, Diffusion, Facilitated Diffusion, Active Transport
i. Diffusion: movement of molecules/particles from area of high concentration to low;
- particles are small (and nonpolar), so NO ENERGY IS INPUT FROM CELL
ii. Osmosis: diffusion of water across a membrane; NO ENERGY (“E”)
iii. Facilitated Diffusion: diffusion assisted by membrane transport proteins; NO “E”
iv. Active Transport: transport of LARGER molecules across membrane
- Energy IS REQUIRED from cell
13) Provide graphic representations of Diffusion, Facilitated Diffusion, Active Transport
- This means, draw diagrams of each. (See the Unit 1 test review sheet.)
14) Define homeostasis. Provide 2 examples.
- Maintenance of “internal stability” or balance.
- Ex: body temperature; pH; blood sugar level; blood oxygen level
15) Why do cells divide? What is DNA overload? As a cell grows, does it place more or less
demands on it’s DNA?
- Cells divide for i. growth of organism, ii. to replace dead body cells, and iii. To keep cell
size small (Surface Area to Volume ratio problem)
- DNA Overload: large cells put too much demand for work on the DNA
- More demand
16) What happens to the volume and surface area of a cell as it grows? As a cell becomes
larger….
- Volume (organelles) of a cell grows faster than Surface Area (cell membrane), so….
17) Cells getting larger (cell growth) causes a number of problems for cells. What are they?
(There are 3)
i. … large cells can’t import nutrients and export wastes fast enough to sustain cell
ii DNA Overload
18) Draw and label a duplicated chromosome. During the cell cycle, when are duplicated
chromosomes visible?
Sister chromatid
centromere
X
- A duplicated chromosome has the classic “X” shape:
telomere
- Duplicated tightly-wound (X-shaped) chromosomes are visible ONLY DURING
MITOSIS.
19) During cell division, what are daughter cells, and how are they related to the parent cell?
- Parent Cell: a cell that is going through the cell cycle
- Daughter Cells: two identical cells created when parent cell divides during mitosis
20) In what phase of the cell cycle is a cell’s DNA replicated? (Be specific.)
- S phase (synthesis) - of Interphase
21) How does the cell cycle compare to cell (nuclear) division?
- Nuclear division (division of the DNA) happens during mitosis (stage of cell cycle)
22) What are the phases of mitosis in their proper sequence? (There are 4) Summarize what
happens in each? (You MUST be able to describe the major events in each stage)
PMAT = stages of mitosis
I-PMAT-i-C = all stages of Cell Cycle
- Prophase: Chromosomes take X-shape; nuclear membrane breaks down; spindle fibers appear
- Metaphase: Chromosomes line up across the “equator” of the cell; are attached to spindle fibers at centromere
- Anaphase: Chromosomes are pulled by spindle fibers to “poles” of cell
- Telophase: Chromosome unwind; nuc membrane reforms; spindles disappear
23) Identify 2 ways the cell cycle is controlled. [Chapter 5, Section 3]
I. “internal” Growth Factors (controls inside the cell):
> proteins (like “cyclins”) whose build up signals steps of cell cycle
II. “external” Growth Factors (2 types of controls from outside the cell):
1) protein signals from other cells
2) contact with other, neighboring cells = “Cell to cell contact”
24) What is CANCER? What is the relationship between cancer and mitosis?
- In CANCER cell division is uncontrolled = CELL REPRODUCES TOO FAST.
- Cells death is normal and programmed = “apoptosis” [ap-up-TOH-sis]
- “Tumors”: disorganized clumps of cancer cells
25) Using the figure:
a. Label the all of the stages of the cell cycle. (A, B, C, D)
b. What is happening (specifically) in stage D?
26) What are cyclins? What is the p53 gene and why is it important?
- Cyclins: (Sec5.3, p137) (Internal) growth/control factors produced by a cell, whose build up
tells the cell when to change phase in cycle. (They are proteins.)
- p53 Gene: a gene in DNA that produces protein that regulates/controls cell cycle speed (like
cyclins)