Download Cell Biology Essential Questions

Cell Biology
Essential Questions
1. What 5 scientists are credited with discovering the modern cell theory?
•_____________________ – first to identify _____________________
•_____________________ – observed greater _____________________ in cells
•_____________________ – found that _____________________ are made of cells
•_____________________ – found _____ ________________ things are made of cells
•_____________________ – found cells only come from other _____________________
2. What are the three major principles of the cell theory?
1. All organisms are made of _____________________.
2. All existing cells are produced by other living _____________________.
3. The _____________________ is the most basic unit of _____________________.
3. What are the major differences between prokaryotic cells and eukaryotic cells and viruses?
• _____________________ have no membrane-bound organelles
DNA is suspended in the _____________________
microscopic _____________________ -celled organisms (ex. Bacteria)
• _____________________ have a nucleus and other membrane bound organelles.
DNA found in the _____________________, the largest organelle
_____________________ or single-celled organisms.
• _____________________ are not cells.
They have only a protein coat surrounding either DNA or RNA
Viruses don’t reproduce on their own. They need a host to reproduce for them.
4. What are the 10 major organelles (& their function) found in both plant and animal cells?
1. _____________________ - which is a network of _____________________ that is constantly changing to
meet the needs of a cell
2. _____________________ - is the storehouse for most of the _____________________ information, or
_______(deoxyribonucleic acid), in your cells
3. _____________________ - dense region where _____________________ are assembled
4. _____________________ (ER) – systems of folded sacs and interconnected channels.
_____________________ ER synthesizes proteins
_____________________ ER modifies or detoxifies lipids.
5. _____________________ - tiny organelles that link __________ ________ together to form proteins.
6. _____________________ - ________________, _______________ in vesicles, and ______________ proteins
to the plasma membrane for secretion
7. _____________________ – small, membrane-bound sacs that _____________________ materials from place
to place within the cell.
8. _____________________ – make _________ to supply _____________________ to the cell
9. _____________________ - fluid-filled sac used for the _____________ of materials needed by a cell
– may include water, food molecules, inorganic ions, and enzymes
10. _____________________ - small region of cytoplasm that produces _____________________
5. What 2 organelles are found only in animal cells?
• _____________________- cylinder-shaped organelles made of short __________________arranged in a circle
o attach to _____________________during cell division
o form _____________________and _____________________in cells
• _____________________- membrane-bound organelles that contain enzymes
o _____________________cells from bacteria and viruses break down damaged or worn-out cell parts
6. What 3 organelles are found only in plant cells?
• _____________________- organelles that carry out _____________________ (chemical reactions that convert
solar energy into energy molecules [glucose])
• ______________ _________________– storage of water enzymes, toxins, wastes; support to the entire plant
• __________ __________- rigid layer that gives ____________, ______________, and _____________to the cell
7. What are cell membranes? What are they made of?
cell membranes are _____________________ between cell and outside environment and controls the passage of
_____________________ into and out of a cell.
Cell membranes are made of _____________________, which have 3 parts…
1. _____________________ group – forms the polar “head” with the glycerol
[hydrophilic = water loving]
2. _____________________ – forms the polar “head” with the phosphate group
[hydrophilic = water loving]
3. two _____________ ___________ chains – forms the non-polar “tail”
[hydrophobic = water fearing]
8. What other molecules can be found in the cell membrane?
• _____________________ - strengthens cell _____________________.
• _____________________ – membrane _____________________, also form _____________________
• _____________________ - _____________________ tags, enabling cells to distinguish one type of cell
from another.
9. What is the “fluid-mosaic” model of cell membranes?
• describes the _____________________ of the molecules that make up a cell membrane
• _____________________ = membrane is _____________________, not rigid, like a fluid
o _____________________ in each layer can move from side to side and slide past each other.
• _____________________ = many _____________________ molecule structures make up membrane
10. What is selective permeability (semipermeable)? Why is this important?
• Some, but not _____________________ materials are allowed to pass
• Keeps good things (_______,_____________________) inside the cell and bad things (_______,
_____________________) outside the cell
11. What is the difference between diffusion and osmosis? How are diffusion and osmosis similar?
• _____________________ is the movement of molecules in a fluid or gas from a region of higher
concentration to a region of lower concentration.
• _____________________ is diffusion (movement of molecules in a fluid or gas from a region of higher
concentration to a region of lower concentration) across a _____________________ membrane.
• Both diffusion and osmosis are types of _____________________ transport, which is the movement of
molecules across a cell membrane without _____________________ input from the cell.
12. What is a concentration gradient?
• A concentration gradient is the _____________________ in the concentration of a substance from one
location to another.
• Molecules diffuse down their concentration gradient—that is, from a region of higher concentration to a
region of lower concentration.
13. What are the differences between isotonic, hypertonic, and hypotonic solutions?
• _____________________ – _____________________ concentrations of water inside and outside a cell;
cell doesn’t change size
• _____________________ – more solutes (ex. Salt) outside a cell; water moves out, cell ____________
• _____________________ – less solutes (ex. Salt) outside a cell than inside; water moves in, cell ______
14. What is facilitated diffusion? How is it different than active transport?
• Facilitated diffusion is the diffusion of molecules across a membrane through _________ ___________
o process is still a form of _____________________ transport
• Active transport drives molecules across a membrane from a region of ______________ concentration
to a region of ______________ concentration
o Not _____________________ transport
o Requires _____________________
15. How is exocytosis different from endocytosis and phagocytosis?
• _____________________ is the release of substances out of a cell by the _____________________ of a
vesicle with the membrane.
• _____________________ is the process of taking liquids or fairly large molecules into a cell by
_____________ them in a membrane
• _____________________ is a type of endocytosis in which the cell membrane engulfs_______ particles
o Ex. _____________________ blood cells engulf invaders
16. What is the cell cycle? What are the 4 main stages of the cell cycle?
The cell cycle is the regular pattern of _____________________, DNA _____________________, and cell
________________ that occurs in eukaryotic cells.
4 stages…
1. _____________________(_______)– normal _____________________ and _____________________
2. _____________________(_______)– DNA _____________________
3. _____________________(_______)- normal _____________________ and _____________________
4. _____________________(_______) – body cell _____________________
17. How fast do cells divide?
• They divide at _____________________ rates
• Could be ________________, ________________, ________________, or ________________
18. Why can’t cells be any bigger or smaller than they are?
• If cells were too _____________________ …
o they wouldn’t have enough ___________________ and _______________ (ex. Mitochondria)
• If cells were too big…
o the ratio of cell _____________________ area to _____________________ would be too small
o Not enough surface area = not enough ________________ and ________________ moving in
and not enough _____________________ moving out
19. What is DNA? How is DNA organized in the body?
• DNA contains the _____________________ information in the cell
• DNA is found coiled into _____________________
o Chromosomes are stored in the _____________________ of a cell
o Each human body cell has _____________________ chromosomes
20. What is the monomer of the DNA polymer?
• _____________________ are the monomer of DNA
• Nucleotides have 3 parts…
1. _____________________
2. _____________________ backbone
3. Nucleotide _____________________
21. How does DNA condense during the early stages of mitosis?
• DNA _____________________ wraps around
• proteins called _____________________, which further coil into
• _____________________, which forms a
• _____________________ _____________________
22. Draw a chromosome. Label the centromere, chromatid, sister chromatids, telomere
23. Which “-phase” gets the cell ready for mitosis, but is not a part of mitosis?
• _____________________
• At the end of interphase DNA ________________ has occurred and the cell is ______ enough to divide.
24. What are the 4 phases of mitosis, and what happens at each? [PMAT] Draw each phase…
1. _____________________ – DNA _____________________, nuclear _____________________ breaks
down, _____________________ move to the side, spindle _____________________ form
2. _____________________ – chromosomes line up in the _____________________, spindle fibers
attach to each chromosome
3. _____________________ – sister _____________________ separate to opposite sides of the cell,
________________ (cytoplasm division) begins
4. _____________________ – nuclear _____________________ forms, chromosomes _______________,
spindle _____________________ fall off
25. What is cytokinesis?
• Cell _____________________ division
• Completes process of cell _____________________
26. What is cancer? What are the most common types? What is the difference between benign and
malignant tumors?
• _____________________ cell division.
• Most common types of cancer in the U.S. are…
o _______________, _______________, _______________, _______________, ______________
• Benign – cells stay _____________________, _____________________ to remove
• Malignant – cells move (_____________________) through the body, very ______________ to remove
27. What are carcinogens?
• Substances known to produce or promote the development of ________________ are called carcinogens
o include tobacco _____________________, air _____________________, __________________
28. What are the 2 major methods of reproduction?
1. _____________________ reproduction
• Combination of two _____________________ (1 ________________, 1 ________________)
2. _____________________ reproduction
• _____________________ – breaking off to form new individual (ex. Sponges, hydra)
• Binary _____________________ – single-celled organism cell division (ex. _______________)
29. What are 2 advantages and 2 disadvantages of sexual reproduction?
• Advantages…
1. lots of _____________________
2. no need to find a _____________________
• Disadvantages…
1. Little genetic _____________________ (offspring have same ________ as parents)
2. Can’t genetically _____________________ to changing conditions (_____________________)
30. What are the levels of organization in a complex organism?
______________________ ______________________ ______________________
______________________ _______________________ ______________________
______________________ _______________________ ______________________ 31. What is cell differentiation?
• Cell differentiation is the process by which ____________________cells develop into their mature
____________________and ____________________
• “____________________cells become working ____________________cells”
32. What are stem cells? What are the 3 unique things that stem cells can do?
• Stem cells are ____________________cells (blank cells)
• Stem cells can…
o ____________________and ____________________themselves for long periods of time
o remain ____________________in form
o develop into a variety of ____________________cell types.
33. Where do stem cells come from? (3 sources)
• ____________________
• ____________________
• ____________________
34. Should there be restrictions on stem cell research?