Biology Study Guide

Cell Structure & Function

  1. ______was one of the first people to identify & see cork cells.
  2. All plants and animals are made of cells…summarizes the work of ______& ______.
  3. List three principles of the cell theory.
  4. The cell theory applies to ______.
  5. Prokaryotes lack a(n)______.
  6. Define eukaryote…be sure to also include three things that they contain….
  7. ______are prokaryotes (what organism?).
  8. ______-stores DNA, controls most of the cell’s processes, & contains information needed to make proteins.
  9. The ______is important to cells mainly because it contains coded instructions for making proteins.
  10. ______are organelles/structures found in the cytoplasm.
  11. ______-cell organelle that breaks down food into molecules the cell can use.
  12. ______-cell organelle/structure which makes protein using coded instructions from the nucleus.
  13. ______-organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use.
  14. ______&______are “energy organelles”…which help to provide a cell with energy.
  15. ______is an energy organelle you would expect to find in plant cells but not in animal cells.
  16. The ______helps a cell keep its shape…
  17. ______& ______are structures that help the cell to carry out cell movement…(cilia & flagella are NOT the answer for this particular question);
  18. The ______helps the cell maintain shape, helps the cell move & helps organelles within the cell move.
  19. The main function of the ______is to support & protect the cell.
  20. Unlike the cell membrane, the cell wall is usually made of tough ______.
  21. The ______serves as the cell’s boundary from its environment in most cells.
  22. The function of the ______is to regulate what materials enter & leave the cell.
  23. Diffusion is the movement of molecules from an area of______concentration to an area of ______concentration.
  24. What do the molecules do on each side of the membrane when the concentration of molecules on each side of the membrane is the same?
  25. ______transport is a means of particle transport that REQUIRES ENERGY.
  26. The DIFFUSION of WATER across a selectively permeable membrane is called ______.
  27. An animal cell that is surrounded by fresh water will______because the osmotic pressure causes water to move into the cell.
  28. ______refers to cells having different jobs in an organism.
  29. ______-a group of similar cells that perform a particular function. List an example.
  30. What is an organ system?
  31. List the levels of organization in a multicellular organism from simplest level to most complex beginning with cells.
  32. If a cell contains a nucleus, it must be a(n) ______.
  33. The assembly of ribosomes begins in a small dense structure called the ______.
  34. Ribosomes stud the surface of the ______.
  35. Cilia & flagella are made of protein filaments called ______.
  36. According to the cell theory, all cells come from existing ______.
  37. In a eukaryote, the material between the cell membrane & the nucleus is called the ______.
  38. During cell division, chromatin condenses to form ______, which are thread-like structures containing genetic material.
  39. Define diffusion.
  40. Be able to distinguish an animal cell from a plant cell by looking at an unlabeled diagram.
  41. From a diagram…be able to label (you have to be able to recognize/identify structures!) & tell the function of cell structures: nucleus, mitochondrion, ribosome, cell membrane, smooth endoplasmic reticulum, rough endoplasmic reticulum, nucleolus, golgi apparatus, cytoplasm;

Also you will have 1 to 3 Essay questions in addition to the multiple choice questions.

* All of the following statements about cells is true.

The common features of prokaryotic and eukaryotic cells are:

DNA, the genetic material contained in one or more chromosomes and located in a nonmembrane bound nucleoid region in prokaryotes and a membrane-bound nucleus in eukaryotes

Plasma membrane, a phospholipid bilayer with proteins that separates the cell from the surrounding environment and functions as a selective barrier for the import and export of materials

Cytoplasm, the rest of the material of the cell within the plasma membrane, excluding the nucleoid region or nucleus, that consists of a fluid portion called the cytosol and the organelles and other particulates suspended in it Ribosomes, the organelles on which protein synthesis takes place

* Light microscopes - use light and glass lenses to magnify an image.

* One centimeter = ___10_____ millimeters.

* Resolution is the ability of an optical instrument to show two close objects as separate.

* Electron microscopes focus electron beams to create a magnified image of an object

*If a scientist wants to examine living cells lining the respiratory tract to determine how the cells use tiny hairs to move dirt and mucus away from the lungs, he would use a light microscope, because it allows observations of whole, live cells

* The idea that all living things are composed of cells and that all cells come from other cells defines cell theory.

* A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its surface, he would use a scanning electron microscope.

* A scanning electron microscope is used to study cell surfaces, whereas a transmission electron microscope is used to study internal cell structures.

* The diameter of most animal and plant cells ranges from 10 to 100 micrometers.

* As cell size increases, the volume increases faster than the surface area.

* Bacterium cells have the greatest surface-to-volume ratio.

* A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and larger. This situation will eventually be problematic, since the cell's ability to absorb nutrients through its outer membrane will not keep increasing as quickly as its cytoplasmic needs.

* Your throat is dry, and you want the last cough drop in the box to last a long time in your mouth. You should keep the cough drop whole. This maintains the largest surface-to-volume ratio, and slows the dissolution of the cough drop.

* Archaea are composed of Prokaryotic cells.

* The Nucleoid is exclusively associated with prokaryotic cells

* The nucleoid region of a prokaryotic cell contains the cell's DNA.

* Prokaryotic cells lack a membrane-enclosed nucleus.

* Both pili and capsule structures are used by prokaryotes for attaching to surfaces.

* The membranous compartmentalization of a cell allows different metabolic processes to occur simultaneously.

* Eukaryotic cells have the following:

…internal membranes greatly increase a cell's total membrane area.

… internal membranes provide an additional area for many metabolic processes occur.

……. internal membranes form membranous compartments called organelles.

……. internal membranes contain proteins essential for metabolic processes.

* You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them through a microscope and see cell walls and membrane-bound organelles. You conclude correctly that the cells are plant cells.

* Unlike animal cells, plant cells have Chloroplasts and cell walls. Unlike plant cells, animal cells have centrioles.

*Characteristics of Cellular metabolism include

… Cellular metabolism includes different processes that require different conditions.

….Cellular metabolism can occur within organelles.

… Cellular metabolism can involve the synthesis of steroid hormones.

… Cellular metabolism often occurs on the surfaces of internal membranes.

* Plasma membranes are permeable to nonpolar molecules such as CO2.

*You would you find the following when looking through a SEM at a cell treated with an enzyme that cleaves proteins at their hydrophilic amino acids.

…….. a cell surface that is devoid of any major structures

* The nucleus of a cell contains DNA.

* Long fibers of DNA and protein are called chromatin.

* During cell reproduction, chromatin fibers coil up into structures called chromosomes.

* The function of the nucleolus is to manufacture ribosomal RNA.

* Protein synthesis requires the use of mRNA, which is translated by the ribosomes into the amino acid sequences of proteins.

* The plasma cell produces thousands of antibodies per second. What type of intracellular structure that would be very prominent within the cell is the endoplasmic reticulum.

* The plasma membrane in the cell is unlikely to contain ribosomes or ribosomal subunits?

* Characteristics of the endomembrane system include

… The endomembrane system is involved in the synthesis, storage, and export of important molecules.

… The endomembrane system includes the rough and smooth endoplasmic reticulum.

… The endomembrane system includes the nuclear envelope.

… The endomembrane system divides the cell into compartments.

* The endomembrane system includes all of the following organelles .

Plasma membrane , endoplasmic reticulum, Golgi apparatus, and lysosome.

* Smooth endoplasmic reticulum stores calcium ions in muscle cells.

* The two main functions of the rough endoplasmic reticulum are the production of ribosomes and steroid hormones

* Secretory proteins are released from the cell through the plasma membrane.

* The cells that produce hair contain a lot of rough endoplasmic reticulum, while the cells that produce the oils that coat the hair contain a lot of smooth endoplasmic reticulum.

* The Golgi apparatus stores, modifies, and packages proteins.

* The Golgi apparatus :

…… works closely with the endoplasmic reticulum.

…. serves as a molecular warehouse and finishing factory.

…. modifies chemicals received from the endoplasmic reticulum.

…. sorts molecules according to their destination.

* Lysosomes:

…. help to digest worn-out or damaged organelles.

…. Lysosomes fuse with food vacuoles to expose nutrients to lysosomal enzymes.

… Lysosomes destroy harmful bacteria engulfed by white blood cells.

… Lysosomes recycle materials within the cell.

* When a cell is deprived of oxygen, its lysosomes tend to burst and release their contents into the cell. As a result of this, that cell will undergo self-digestion and die.

* Tay-Sachs disease results from the malfunction of lysosomes.

* Tay-Sachs disease causes an accumulation of lipids in brain cells.

* Functions of a plant cell central vacuole include:

…… The central vacuole of a plant cell may help increase the size of cells by absorbing water.

…… The central vacuole of a plant cell may store pigments that will help attract pollinating insects.

……. The central vacuole of a plant cell may store waste products.

…… The central vacuole of a plant cell may store poisons.

* Contractile vacuoles prevent cells from bursting as a result of the influx of excess water.

* A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of these organisms taken from the pond would find that they have gained water and burst.

* Peroxisome are involved in the catabolism of fatty acids and the detoxification of alcohol.

* Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. The order of the structures through which insulin passes from its production to its exit from the cell is as follows: rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane

* The function of mitochondria is cellular respiration.

* Cyanide inhibits mitochondrial function; as a result, the rate of ATP synthesis decreases.

* The Cristae of a mitochondrion is/are an adaptation that increases the surface area and enhances a mitochondrion's ability to produce ATP.

* The function of chloroplasts is photosynthesis.

* The stroma is the thick fluid enclosed by the inner chloroplast membrane.

* Mitochondria differ from chloroplasts in that mitochondria contain membrane folds called cristae, whereas chloroplasts contain disk-like vesicles in stacks called grana.

* The endosymbiosis hypothesis proposes that a small cell lived inside a larger cell to the benefit of both cells.

* The endosymbiosis hypothesis is supported by all of the following pieces of evidence;

… mitochondria have circular DNA like prokaryotes, chloroplasts have ribosomes like prokaryotes, mitochondria have a double membrane, chloroplasts split like prokaryotes.

* Microfilaments differ from microtubules in that microfilaments are mainly composed of actin, whereas microtubules are composed of tubulin.

* The cytoskeleton helps to support cells.

… The cytoskeleton is composed of three types of fibers: microfilaments, microtubules, and intermediate filaments.

… The cytoskeleton plays an important role in amoeboid motion.

… The cytoskeleton includes fibrous and globular proteins.

* Intermediate filaments surround the nucleus.

* A drug that interferes with microtubule formation is likely to completely disrupt the movements of sperm cells.

* Cilia differ from flagella in that cilia are typically more numerous and shorter than flagella.

* A basal body is similar in structure to centrioles.

* Dynein arms are found on microtubules in cilia and flagella and cause movement by grabbing and pulling at adjacent microtubule.

* A woman is having trouble becoming pregnant. Examination of her partner's sperm indicates that dynein arms are missing from the flagella in his sperm cells. A physician explains that this could interfere with fertility by preventing the sperm from swimming to the egg cell.

* Decreased fertility in men from developed countries may be related to increased exposure to hormone-like chemicals in the environment.

* Most animal cells are embedded in an extracellular matrix.

* Most cells from multicellular organisms must be attached to their surroundings via integrins. Failure to maintain this contact will usually results in the death of the cell.

* Integrity of the inner lining of the digestive tract would be most affected by a mutation that prevented cells from forming tight junctions.

* Skin cells are attached to the extracellular matrix by anchoring junctions.

* It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would best facilitate this are communicating junctions.

* Plant cell walls :

…. consist of cellulose fibers embedded in a matrix of polysaccharides and proteins.

…. The cell wall of one plant cell is separated from the cell wall of another by a layer of sticky polysaccharides.

…. are multilayered structures.

… Wood is primarily composed of plant cell walls.

* Plasmodesmata : penetrate plant cell walls, Plasmodesmata are one type of cell junction in plants, Plasmodesmata carry chemical messages between plant cells, Plasmodesmata carry nutrients between plant cells.

* Peroxisomes are associated with the breakdown of harmful substances or substances that are no longer needed by the cell?

* Characteristics of cells include:?

… All cells are enclosed in a membrane that maintains internal conditions different from the surroundings; can interconvert forms of energy, can interconvert chemical materials, have DNA as their genetic material.

* A child dies following a series of chronic bacterial infections. At the autopsy, the physicians are startled to see that the child's white blood cells are loaded with vacuoles containing intact bacteria. An explanation for this could be a defect in the lysosomes of the white blood cells prevented the cells from destroying engulfed bacteria.