Test 3- Cells

Question 1

Explain the significance of cells

Answer 1

-All living things are made of cells
- There are 100 trillion of them
- Everyone has a complete “instruction set” of DNA on the chromosomes

Question 2

Explain what cells are

Answer 2

The structural and functional unit of life

Question 3

Explain the “Cell Theory”

Answer 3

• All organisms are made of cells
• It is the simplest collection of matter that can perform all the characteristics of life
• They arise only by division of a previously existing cell

Question 4

Explain the difference between macroscopic, microscopic, and sub microscopic

Answer 4

Mac: Can be seen by the unaided eye
Mic: Can be seen under a light microscope OR an electron microscope
Sub: Can be seen only from an electron microscope

Question 5

Explain who Anton Van Leevenholes was

Answer 5

The first noted scientist to use a lens to greatly enhance viewing small organisms

Question 6

Explain what the two types of electron microscopes are and what they see

Answer 6

• Scanning Electron Microscope (SEM): Scans the surface of very small structures
• Transmission Electron Microscopes (TEM): Shows images of the interior of very small structures

Question 7

Compare/ contrast the two types of cells in life on Earth

Answer 7

• Prokaryotic: Only organisms that are bacteria or archea consist of prokaryotic cells. Prokaryotic cells have: Flagella, cell wall, cell membrane, capsule, nucleoid, and ribosomes
• Eukaryotic: Protists, fungi, and animals consist of eukaryotic cells. Eukaryotic cells have: Nucleus, Nucleolus, Mitochondria, and ribosomes

Question 8

Explain the major characteristics of prokaryotic cells

Answer 8

• No true nucleus with a membrane
• DNA is in an unbound region called the nucleoid
• It contains zero membrane bound organelles
• The cytoplasm is bound by the plasma membrane

Question 9

Explain the major characteristics of eukaryotic cells

Answer 9

• Nucleus
• Cytoplasm
• Cell membrane
• DNA in the nucleus is bounded by a membranous nuclear membrane
• It contains membrane bound organelles
• Eukaryotic cells are generally much larger than prokaryotic cells

Question 10

Explain the cell membranes structure and function

Answer 10

• Structure: Double layer of phospholipids with proteins interspersed randomly
• Function: A selective barrier that allows sufficient passage of oxygen, nutrients, and waste

Question 11

Explain why cells have a certain size

Answer 11

The logistics carrying out cellular metabolism sets limits on the size of cells

Question 12

Explain the structure and functions of a eukaryotic cells nucleus:

Answer 12

• Most of the cells DNA and genes are stored in the nucleus
• The nuclear membrane encloses the nucleus, separating it from the cytoplasm
• mRNA comes out the the nuclear membranes pores
• The nuclear membrane is a double layer (bilayer)

Question 13

Explain chromatin/ chromosomes

Answer 13

• DNA in a cells nucleus and proteins form the genetic material, chromatin
• Chromosomes are created when the cell divides

Question 14

Explain the components of the endomembrane system

Answer 14

• Nuclear envelope
• ER
• Golgi Apparatus
• Lysosomes
• Vacuoles
• Plasma Membrane