38 terms

Biology Test

The exoskeleton is composed of thin fiberous elements that form a framework for the cell
Controls materials entering and leaving the cell
Cell Membrane
True or False: Cells have a support structure within the cytoplasm called cytoskeleton
True or False: A phospholipid has a hydrophobic head attached to a long hydrophilic tail
Who was the first scientist to describe living cells as seen through a simple microscope
Anton van Leevwenhoek & Robert Hooke
True or False: The plasma membrane is a bilayer of lipid molecules with protein molecules embedded in it
Clear fluid inside the cell
Firm, protective structure that gives the cell its shape in plants
Cell Wall
Modifies proteins chemically then repackages them
Golgi Apparatus
What cell structures make plant and animal cells different
Plant- Cell Wall,Chloroplast, Vacuole
Animal- Lysosomes, Flagella, Centrioles
What happens to a higher concentration of disolved molecule on one side of a cell membrane during the process of diffusion
The higher concentration begins to defuse into the area with lower concentration.
What is osmosis
Diffusion of water through a selectively permeable membrane
[HIGH] - [LOW]
True or False: The structure and properties of the cell wall allow it to be selective and maintain homeostasis
True or False: The plasma membrane can contain cholesterol, which tends to make the membrane more stable
Place the following in order from smallest to largest level of organization
(Tissue, Organ, Organ System, Individual Cells, Organism)
Individual Cell, Tissue, Organ, Organ System, Organism
(Cells make up tissue, tissues make up organs, organs make up organ systems, organ systems make up organisms)
Compare and Contrast endocytosis and exocytosis
Endocytosis-process by which cells absorb molecules (such as proteins) from outside
Exocytosis- Cells direct the contents of secretory visels out the cell membrane
Describe the structure of a phospholipid
Made up of a head and 2 fatty acid tails.
Head- phosphate and glycerol (hydrophilic)
Tail- fatty acid (hydrophobic)
Which end of a phospholipid is attracted to water
head (hydrophilic)
Plants have cells that contain chloroplast. Why must their cells contain mitochondria as well
Chloroplast- makes food by trapping light energy to convert water and carbon dioxide to form oxygen and glucose (photosynthesis)
Mitochondria- provides energy for the cells use by extracting the energy from glucose molecules and storing ATP
How are phospholipids arranged in the plasma membrane
In a dual layer, the tails are facing toward each other. The head i son the outer surface
What is the function of membrane proteins
Transport proteins. Diffusion and active transport
True or False: Transport proteins span the cell membrane allowing the selectively permeable membrane to regulate which molecules enter and leave a cell
Providing temporary storage of food, enzymes and waste products
Digest excess or worn out cell parts, food particles, and invading viruses or bacteria
Folded membranes that serve as the delivery/ transprtaion system of the cell
Endoplasmic Reticulum
What scientist concluded that all plants are made of cells
Mathias Scheden
Organelle that manages all cell functions in eukaryotic cell
Sites of protein synthesis
A green pigment that traps energy from sunlight and gives plants there green color
Produce a useable form of energy for the cell
What is the functions of cholesterol molecules
help membrane maintain homeostasis at very high temperatures. Cholesterol keeps fatty acid tails from touching
True or False: The fluid mosiac model describes the plasma membrane as a structure that is liquid and very rigid
What scientist conducted that all animals are composed of cells
Thodore Shwann
True or False: Microtubules of the cytoskeleton are thin, hollow cylinder made of protein
Cilla and Flagella are cell surface structures that are adapted for respiration
Flagella are short numeroud hair like projections from the plasma membrane
What scientist observed that cork was composed of tiny hollow boxes that he called cells
Robert Hooke
What are the 3 parts of the cell theory
1. cells are the smallest unit of life
2. all living organisms are made of cells
3. all cells come from preexisting cells (these are theories)