Biology Chapter 7

The man who determined that a cell contains a nucleus responsible for cell divisiton which resulted in another living cell was

Virchow

Cell Theory

-all living organisims are composed of one or more cells -cells are the basic unit of structure and organization of all living organisms -cells arise only from previously exisiting cells, with cells passing copies of thier genetic material on to their daughter cells.

In what decade did the cell theory become an accepted part of biology?

1850's

An Electron microscope can magnify objects around 500,000 times. How does this compare to the magnification of a compound light microscope?

500 times higher

Compare and Contrast Prokaryotes versus Eukaryotes

Both have plasma membrane, but one cell contains many distinct internal structures called organelles. Eukaryotic cells contain a nucleus and member bound organelles, prokaryotic celss are defined as cells without a nucleus or membrane bound organelles.

Compare and contrast active and passive transport across the plasma membrane

Active and Passive transport are biological processes that move oxygen, water and nutrients into cells and remove waste products. Active transport requires chemical energy because it is the movement of biochemicals from areas of lower concentration to areas of higher concentration. On the other hand, passive trasport moves biochemicals from areas of high concentration to areas of low concentration; so it does not require energy.

Electron microscope

Also called transmission electron microscope TEM becase electrons are passed or transmitted through a specimen to a fluroescent screen

Which substance on teh plasma membrane helps identify chemical signals from outside the cell?

Carbohydrate chain

Cholesterol is repelled by water and can be found between the layers of the phospholipids in the plasma membrane. What can be concluded from this information?

Cholesterol is nonpolar

Compound light microscope

Consists of a series of glass lenses and uses visible light to produce a magnified image.

Example of active transport

Exocytosis

Of the other components of the plasma membrane, the one host responsible for anchoring the plasma membrane to the cells internal support structure and giving the cell its shape is?

Proteins

Who concluded that old plants are mad of living cells

Schleiden

Cilia and Flagella are used to move cells through watery environments. What role do these cell parts play on stationary cells?

They move substances along the surface of the cell.

Algal cells are placed in an isotonic solution. additional amounts of solutes are slowly added to the solution . What happens to the cells?

They will shrink.

Chloroplasts are organelles taht convert light energy to sugars. These organelles are found only in plants. Which organelles are found only in animals?

centrioles

Water moves into a cell placed in a ________Solution?

hypotonic

Which is the main effect of having the polar and non ploar ends of phospholipid molecules oriented as they are?

it controls the movement of substances across the membrane

What types of materials are expelled from cells during exocytosis?

large molecules such as hormones?

Example of passive transport

osmosis

If a cell is placed in salt water , water leaves the cell by ?

osmosis

Which part of the phospholipid allows the cell membrane to interact with water in it environment?

phosphate group because it is polar

The plasma membrane structure is best described as?

polar layers on both the inside and outside of the membrane with non polar layers on the middle

Which of the following organell is the only one not surrounded by phosphiolipid membrane

ribosome

A cells contents would be the same as its surroundings , were it not for

selective permeability

Which of the following instruments allows a scientist to study intracellular (inside the cell) structure?

transmission electron microscope