Eukaryotes and Prokaryotes

Question 1

Are animal and plant cells eukaryotic or prokaryotic cells?

Answer 1

Eukaryotic cells

Question 2

prokaryotic cells:

Answer 2

-plasmids (small rings of DNA)
-Genetic material is not enclosed in the nucleus and it doesn’t have membrane bound organelle it is also smaller
-much smaller in comparison to eukaryotic cells
-have cytoplasm and a call membrane which is surrounded by a cell wall
-the cell wall isnt made of cellulose like a plant cell wall, its made of peptidoglycan
genetic material isn’t enclosed in the nucleus, its in a single loop of DNA
-Example: prokaryotic cells

Question 3

what organisms are bacteria cells?

Answer 3

-single celled organisms
-prokaryotic cells

Question 4

what are bacteria cells made up of?

Answer 4

• cytoplasm
• cell membrane
• cell wall
• genetic info is not enclosed in a nucleus - it is a single looped chromosome found free in the
cytoplasm
• plasmids
• ribosomes
• flagella
• capsule(most bacteria)
• pili

Question 5

Function of flagella:

Answer 5

• to assist the cell in movement
• long tail for movement

Question 6

Function of capsule:

Answer 6

• For protection from damage
• For sticking prokaryotic cells together

Question 7

Function of pili:

Answer 7

• For directional movement
• For sticking to surfaces e.g. bacteria may stick to a body of cells to begin causing diseases

Question 8

Eukaryotic cells:

Answer 8

• type of cell which contains its genetic material (DNA)
enclosed in its nucleus, and has other membrane bound
organelle like mitochondria
• has a cell membrane and a cytoplasm

Question 9

Function of plasmids:

Answer 9

• in bacteria cells
• extra circular bits of DNA
• unlike chromosomal DNA, plasmid DNA can move from one bacterium to another
• transfers genetic material from one cell to another
• genes in the plasmid can be for anti-biotic resistance
• some produce toxins

Question 10

What was the classification system like pre-1970?

Answer 10

• Living things were classified into 5 kingdoms
• They were classified based on observable characteristics
• Bacteria and archaea were grouped together

Question 11

Archaea:

Answer 11

uni-cellular organisms that are extremophiles (love extreme places)
as they live in extreme places e.g. under water volcanoes

Question 12

What was the classification system like post-1979?

Answer 12

A 3 domain system was developed that separated bacteria and archaea

Question 13

Why were archaea and bacteria separated in the post-1970
classification system?

Answer 13

1. Although the size and structure of archaea ribosomes are the same as bacteria (which is why
   they were put in the same kingdom pre - 1970) the nucleic acid in the archaea ribosomes were more like eukaryotes whereas bacteria are prokaryotes.
2. DNA sequencing showed archaea DNA was nothing like
   bacteria DNA - unlike ‘anything we’ve ever seen’.

Question 14

How do you calculate the cell magnification from an image?

Answer 14

Magnification = Image Size/Actual size

Question 15

How do you calculate the order of magnitude?

Answer 15

• Convert to same unit
• Put in standard form
• Find difference between powers

Question 16

millimetres (mm) to centimetres (cm)

Answer 16

x10

Question 17

micrometres (um) to millimetres (mm)

Answer 17

x1000

Question 18

Nano metres (nm) to micrometers (um)

Answer 18

x1000