Lecture 4

Question 1

Who were cells discovered by?

Answer 1

Robert Hook in 1665.

Question 2

Who proposed the cell theory?

Answer 2

Mathias Schleiden and Theodor Schwann.

Question 3

What is the Cell Theory?

Answer 3

1. All organisms are composed of cells
2. Cells are the smallest living thing
3. Cells arise only from pre-existing cells.

Question 4

Why is the size of cells limited?

Answer 4

Because they rely on diffusion of substances in and out of cells.

Question 5

What does high surface to volume ratio promote efficiency of in a cell?

Answer 5

1. Acquisition of nutrients
2. Disposal of wastes

Question 6

What is resolution?

Answer 6

The minimum distance two points can be apart and still be distinguished as two seperate points.

Question 7

How far apart must two objects be for the naked eye to tell them apart?

Answer 7

100 micrometers.

Question 8

What are 2 types of microscopes?

Answer 8

1. Light microscopes
2. Electron microscopes

Question 9

What are 4 structural similarities of cells?

Answer 9

1. Nucleoid or nucleus where DNA is located
2. Cytoplasm
3. Ribosomes
4. Plasma membrane

Question 10

What are structural components of prokaryotic cells?

Answer 10

1. Plasma membrane
2. No nucleus
3. Cytoplasm (fluid within membrane)
4. No true organelles

Question 11

What are structural components of Eukaryotic cells?

Answer 11

1. Plasma membrane
2. Nucleus
3. Cytoplasm
4. Organelles

Question 12

What is cytoplasm?

Answer 12

fluid within membrane in a cell.

Question 13

What is the nucleus of a cell?

Answer 13

A membrane bound information center.

Question 14

What are organelles?

Answer 14

membrane bound structures with specialized functions.

Question 15

Are human cells prokaryotic or Eukaryotic?

Answer 15

Eukaryotic.

Question 16

Which kind of cell is simpler?

Answer 16

Prokaryotic.

Question 17

What are flagella?

Answer 17

Structures which rotary motion is used to propel the cell.

Question 18

What is the nucleus?

Answer 18

The control center of the cell.

Question 19

What do ribosomes do?

Answer 19

Make proteins.

Question 20

What is the endoplasmic reticulum (ER)?

Answer 20

The manufacturing center.

Question 21

What are 2 types of ERs?

Answer 21

1. Rough Endoplasmic Reticulum (RER)
   - bound ribosomes
2. Smooth Endoplasmic Reticulum (SER)
   - unbound ribosomes

Question 22

What is the golgi apparatus?

Answer 22

The packing and shipping center.

Question 23

What are lysosomes?

Answer 23

Recycling and trash centers.

Question 24

What are peroxisomes?

Answer 24

The reaction center.

Question 25

What are vacuoles?

Answer 25

Storage and reaction center.

Question 26

What are 3 types of vacuoles?

Answer 26

1. Central vacuole (in plant cells) 2. Storage vacuoles (in plants) 3. Contractile vacuole (in some fungi and protists)

Question 27

What is the mitochondria?

Answer 27

The power plant of the cell.

Question 28

What are chloroplasts?

Answer 28

Organelles present in cells of plants and some other eukaryotes.

Question 29

What is cytoskeleton?

Answer 29

Structural support and transport.

Question 30

What are 3 types of fibers?

Answer 30

1. Microfilaments (actin filaments) 2. Microtubules 3. Intermediate filaments

Question 31

What are centrosomes?

Answer 31

Microtubule-organizing center.

Question 32

What are 3 types of cell connections?

Answer 32

1. Adhesive junctions 2. Septate (or tight) junctions 3. Communicating junctions

Question 33

What are adhesive junctions?

Answer 33

They attach the cytoskeletons of neighboring cells

Question 34

What are septate (tight) junctions?

Answer 34

They connect the plasma membrane of adjacent cells in a sheet (water proof, so nothing leaks).

Question 35

What are communicating junctions?

Answer 35

Chemical or electrical passes directly from one cell to another.

Question 36

What are plasmodesmata?

Answer 36

Specialized openings plant cells have adjoining cytoplasm of adjacent cells.