1.1 Intro to Cells

Question 1

3 Types of Cells

Answer 1

Archaea
Bacteria
Eukaryotes

Question 2

Common features of the types of cells

Answer 2

• A plasma membrane_that separates the cell from its environment.
• Cytoplasm_comprised of the jelly-like cytosol inside the cell.
• Ribosomes_that are important for protein synthesis.
• DNA_to store and transmit hereditary informatiom.

Question 3

Prokaryotes

Answer 3

means “before nucleus”

• prokaryotes don’t have a nuclei.
• instead the cell_ is comprised of single circular chromosomes in the central part of the part of the cell called the nucleoid.

Question 4

Eukaryotes

Answer 4

Has nucleus.
- A nucleus with a double membrane_that enclose DNA.
In addition..
Eukaryotic cells tend to have_a variety of membrane bound organelles._ compartmentalisation functions.

Question 5

Cell size

Answer 5

• As cells increase in size._Its surface area -to volume decreases.
• As cells grow in size- they become less efficient._the plasma membrane will not have sufficient surface area to support the rate of diffusion required for the increased volume.

Question 6

Cell size2

Answer 6

-As nutrients diffuse into the cell-sphere is the shape where nutrients would travel less to reach the centre.
Shorter the distance- the faster the nutrients and waste have to travel.

Question 7

Surface area to volume

Answer 7

Surface area alone cannot influence the rate of exchange_its the volume to surface area ratio that key.
Increasing number of cell -> theres less area for materials to diffuse.

Question 8

Volume

Answer 8

• The volume of an organism determines the number of substances that need to be taken in or out.
• Increase in volumes = to more materials needed for metabolism.

Question 9

Prokaryotes and sa:v

Answer 9

Have a large SA:V ratio._Large surface area

• More materials are needed metabolism.
• Slower rates of exchange compared to eukaryotes.

Question 10

Thin membrane

Answer 10

-Reduces diffusion distance.

Question 11

Transport systems

Answer 11

Allow for higher concentration gradient.
Allow substances to move closer to each other.
eg.
Blood vessels 
xylem
lungs
gills

Question 12

Eukaryotes vs prokaryotes

Answer 12

Similarities

• both contain organelles
• both have a phospholipid bi-layer cell membrane.

Question 13

Eukaryotes vs Prokaryotes

Answer 13

Differences
-prokaryotic cells make up single celled prokaryotic organisms.

• Eukaryotic cells make up complex Eukaryotic organisms(animals, plants, fungi and algae)
• Eukaryotic cells-larger eg. 10-100 micro m
• Prokaryotic cells-smaller eg. 0.1 -5.0 micro m)
• Prokaryotes_ cells arise from other cells by binary fission.
• Eukaryotes_cell arise through mitosis and meiosis .