2.1-Prokaryotic cells

Question 1

What are bacteria?

Answer 1

Bacteria are microorganisms. They have prokaryotic cells.

Question 2

How are prokaryotic and eukaryotic cells similar?

Answer 2

They have:

• A plasma membrane
• Cytoplasm
• Ribosomes for assembling amino acids into proteins
• DNA and RNA

Question 3

How are prokaryotic cells different from eukaryotic cells?

Answer 3

• Much smaller
• Have a much less well-developed cytoskeleton with no centrioles
• Do not have a nucleus
• Do not have membrane bound organelles such as mitochondria, endoplasmic reticulum, chloroplast or golgli apparatus.
• Have a wall made of peptidoglycan and not cellulose
• Have smaller ribosomes
• Have naked DNA that is not wound around histone proteins but floats free in the cytoplasm as a loop (not linear chromosomes).

Question 4

What extra components do prokaryotic cells have?

Answer 4

• A protective waxy capsule surrounding their cell wall
• Small loops f DNA called plasmids as well as the main large loop of DNA
• Flagella- long whip like projections that enable them to move. The structure of these flagella differs from that of a eukaryotic undulipodia
• Pili- smaller hair like projections that enable the bacteria to adhere to host cells or to each other and allow the passage of plasmid DNA from one cell to another.

Question 5

What does a bacteria look like?

Answer 5

REFER TO BOOK

Question 6

What do prokaryotic cells divided?

Answer 6

Prokaryotic cells divide by binary fission and not by mitosis. They do not have linear chromosomes, so could not carry out mitosis.

Question 7

What happens before a prokaryotic cells divides in binary fission?

Answer 7

-However,before they divide, their DNA is copied so that each new cell receives the large loop of DNA and any smaller plasmids.

Question 8

What type of organelles do prokaryotic have?

Answer 8

Prokaryotes (bacteria) do not have any membrane-bound organelles, but they do have organelles that are not covered by a membrane, such as ribosomes.

Question 9

Why are bacteria microorganisms?

Answer 9

Bacteria are microorganisms because they are very small
They are also prokaryotic because of their cells structures. However, not all microorganism are prokaryotes. Yeast (which is a single- celled fungus) and amoebae have eukaryotic cells

Question 10

What are viruses?

Answer 10

Viruses are microscopic but they don’t have cells