Ch.8 * Assesment

How does a light microscope work?

visible light is passed through the specimen and then through glass lenses > magnify what you view

Despite differences in size and shape, at some point all cells have DNA and a

B - cell membrane

German scientists Schleiden and Schwann determined that the basic unit of structure and function in living things is the

C- cell

What basic concept of biology includes the idea that new cells can be produced only by the division of existing cells?

Cell theory

50) Write a paragraph that defines and describes the cell theory. Include a familiar organism, such as a tree or a cat, as an example to illustrate the theory.

Cell theory: -all living things r composed of cells - cell is the basic functional unit of life -the chemical reactions of life take place inside the cell -cells arise only from pre-existing cells -cells carry genetic info in the form of DNA (which is passed from parent cell to daughter cell)

32) In general, how do cells in a multicellular organism communicate?

Chemical messengers communicate among cells in multicellular organisms

??45)Classify each of the cells listed in the table as either prokaryotic or eukaryotic.

Eykaryotes: golgi apparatus, mitochondria, nucleus; Eukaryotes and Prokaryotes: DNA, cell membrane, cytoplasm, ribosomes

If you wanted to observe a living organism—an amoeba for example—which type of microscope would you use?

Light microscope.

38 )Why is intercellular communication essential for a multicellular organism to function properly?

Multicellular organisms rely on specialized cells that complete distinct tasks. Communication allows the cells to work together in an organized way, and to maintain homeostasis for the organism when changes occur in the environment.

Identify evidence that this micrograph is from a scanning electron microscope.

The cell surface is detailed and clear, 3-d, and you can't see inside of the cell.

In what important way are prokaryotic cells and eukaryotic cells different?

The genetic material of prokaryotic cells isn't inside of the nucleus, but in eukaryotic cells, their nucleus contains most of the cell's genetic material.

39) Pacemakers are devices that help keep heart muscles contracting at a steady rate. If a person needs a pacemaker, what does that suggest about his or her heart cells' ability to send and receive messages?

Their heart cells are likely not transmitting or recieving signals properly.

Why are microscopes useful tools in biology?

They let you study cells and cellular components that are too small to see with only the eye.