prokaryotic cells

Question 1

cytoplasm

Answer 1

in prokaryotic cells - no membrane-bound organelles

it has ribosomes but they’re smaller than those in a eukaryotic cell

Question 2

plasma membrane

Answer 2

mainly made of lipids and proteins

controls the movement of substances into and out of the cell

Question 3

cell wall

Answer 3

supports the cell and prevents it from changing shape

it’s made of a polymer called murein which is a glycoprotein (a protein with a carbohydrate attached)

Question 4

flagellum

Answer 4

a long, hair-like structure that rotates to make the prokaryotic cell move

not all prokaryotes have a flagellum
some have more than one

Question 5

nucleus

Answer 5

prokaryotic cells don’t contain a nucleus
instead, the DNA floats free in the cytoplasm
It’s circular DNA, present as one long coiled-up strand
It’s not attached to any histone proteins

Question 6

Plasmids

Answer 6

small loops of DNA that aren’t part of the main circular DNA molecule
Plasmids contain genes for things like antibiotic resistance, and can be passed between prokaryotes
Plasmids are not always present in prokaryotic cells
Some have several plasmids

Question 7

Capsule

Answer 7

some prokaryotes eg bacteria have a capsule made up of secrete slime
it helps to protect bacteria from attack by cells of the immune system

Question 8

binary fission

Answer 8

1 - the circular DNA and plasmids replicate
- the main DNA loop is only replicated once, but plasmids can be replicated loads of times

2 - the cell gets bigger and the DNA loops mode to opposite ‘poles’ of the cell

3 - the cytoplasm begins to divide and new cell walls begin to form

4 - the cytoplasm divides and two daughter cells are produced, each daughter cell has one copy of the circular DNA, but can have a variable number of copies of the plasmid