Bio Exam 2
Which of the following is true concerning cancer cells?
-They do not exhibit density-dependent inhibition when growing in culture. -When they stop dividing, they do so at random points in the cell cycle. -They are not subject to cell cycle controls.
If there are 20 chromatids in a cell, how many centromeres are there?
10
A single carbon atom can form a maximum of ______ covalent bond(s).
4
A cell containing 92 chromatids at metaphase of mitosis would, at its completion, produce two nuclei each containing how many chromosomes?
46
Density-dependent inhibition is explained by which of the following?
As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing.
Name 5 things in plant cells that aren't in animal cells
Chloroplast, central vacuole, tonoplast, cell wall, plasmodesmata
Lysosome
Digestive organelle where macromolecules are hydrolyzed
Nuclear envelope
Double membrane enclosing the nucleus perforated with pores; continuous with ER.
Cells that are in a nondividing state are in which phase?
G-0
Nucleus
Houses the DNA. Contains the nuclear envelope, Nucleolus & chromatin
Flagellum
Locomotion organelle present in some animal cells; composed of membrane-enclosed microtubules.
Name 3 things in animal cells that aren't in plant cells
Lysosomes, centrioles, flagella (in some plant sperm)
This is the shortest part of the cell cycle:
M
Chromatin
Material consisting of DNA and proteins; visible as individual chromosomes in a dividing cell.
Plasma Membrane
Membrane enclosing the cell.
Tonoplast
Membrane enclosing the central vacuole.
Endoplasmic Reticulum (ER)
Network of membranous sacs and tubes; active in membrane synthesis and other synthetic and metobolic processes; has rough and smooth regions
Nucleolus
Nonmembranous organelle involved in production of ribosomes, a nucleus has one more nucleoli.
Peroxisome
Organelle with various specialized metabolic functions; produces hydrogen peroxide.
Which of the following is released by platelets in the vicinity of an injury?
PDGF
Chloroplast
Photosynthetic organelle; converts energy of sunlight to chemical energy stored in sugar molecules.
Central vacuole
Prominent organelle in older plant cells; functions include storage, breakdown of water products, hydrolysis of macromolecules; enlargement of vacuole is a major mechanism of plant growth.
How does RNA differ from DNA?
RNA contains uracil; DNA contains thymine.
Centrosomes
Region where the cell's microtubles are initiated, in an animal cell, contains a pair of centrioles (function unknown)
Cytoskeleton
Reinforcements cell's shape, functions in cell movement; components are made of protein. Consists of microfilaments, Intermediate filaments, microtubules.
How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle?
The daughter cells have the same number of chromosomes and the same amount of DNA.
Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei re-forming on either side of the cell plate. This cell is most likely
a plant cell in the process of cytokinesis.
What is a chromatid?
a replicate chromosome
The primary structure of a protein is ______.
an α helix or a pleated sheet
Which term describes centromeres uncoupling, sister chromatids separating, and the two new chromosomes moving to opposite poles of the cell?
anaphase
What theory states that all living things are composed of cells?
cell theory
Plant cells, unlike animal cells, are characterized by the presence of a ______.
cell wall and central vacuole
In the cells of some organisms, mitosis occurs without cytokinesis. This will result in
cells with more than one nucleus.
Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?
centrosome
Plasmodesmata
channels through cell walls that connect the cytoplasms of adjacent cells.
Destruction of a protein's shape is called ______.
denaturation
Complete the equation: monosaccharide + monosaccharide → ______ + water
disaccharide
A glycerol with three fatty acids attached is referred to as a ______.
fat
Animals store carbohydrates as ______.
glycogen
Lysosomes are responsible for ______.
intracellular digestion
Vacuoles are ______.
membranous sacs
Rhibosomes
nonmembranous organelles (small brown dots) that make proteins; free in cytoplasm or bound to rough ER or nuclear envelope.
What name is given to the organelle that manufactures the components of ribosomes?
nucleolus
Nucleic acids are polymers of ______ monomers.
nucleotide
Where does protein synthesis take place?
on ribosomes
Golgi apparatus
organelle active in synthesis, modification, sorting, and secretion of cell products.
Mitochondrian
organelle where cellular respiration occurs and most ATP is generated
The concept of a membrane as a fluid mosaic reflects the ability of ______.
phospholipids and proteins to drift about in the plane of the membrane
Microvilli
projections that increase the cell's surface area.
When using a light microscope to view a cell you obtained from scraping under your fingernails, you notice that the cell lacks a nucleus; therefore, you conclude that the cell must be a type of ______ cell.
prokaryotic
Which is a general term for enzymes that activate or inactivate other proteins by phosphorylating them?
protein kinase
Which of the following is a function of the Golgi apparatus?
protein modification
Which of the following does not occur during mitosis?
replication of the DNA
What type of microscope would be best for studying the detailed structure of the surface of a plasma membrane?
scanning electron microscope
Similar to the nucleus, chloroplasts and mitochondria are ______.
surrounded by two membranes
DNA nucleotides include ______.
thymine, guanine, adenine, and cytosine