4.1.1.1 Eukaryotes and Prokaryotes

Question 1

Are animal and plant cells eukaryotic or prokaryotic cells?

Answer 1

Eukaryotic Cells

Question 2

Prokaryotic Cells

Answer 2

-Genetic material is not enclosed in the nucleus and it doesn’t have membrane bound organelle it is also smaller in comparison to a eukaryotic cell

-Much smaller in comparison to eukaryotic cells

-Have a cytoplasm and a cell membrane which is surrounded by a cell wall

-The cell wall isn’t made of cellulose like a plant cell wall, it is made of peptidoglycan which means it isn’t was rigid

-Genetic material isn’t enclosed in the nucleus, it is a single DNA loop found in the cytoplasm

-There may be one or more small rings of DNA called plasmids

-Bacteria cells are prokaryotic cells

Question 3

What type of organisms are bacteria cells?

Answer 3

single celled (unicellular) 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 Capsule (most bacteria):

Answer 5

-For protection from damage

-For sticking prokaryotic cells together

Question 6

Function of Pili:

Answer 6

-For directional movement

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

Question 7

Eukaryotic Cell:

Answer 7

-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 8

Archaea:

Answer 8

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

Question 8

What was the classification system like pre-1970?

Answer 8

-Living things were classified into 5 kingdoms

-They were classified based on observable characteristics

-Bacteria and archaea were grouped together

Question 9

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

Answer 9

-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.

-DNA sequencing showed archaea DNA was nothing like bacteria DNA – unlike ‘anything we’ve ever seen’.

Question 10

What was the classification system like post-1970?

Answer 10

A 3 domain system was developed that separated bacteria and archaea