Prokaryotic Cell Structures

Question 1

They also differ from eukaryotic cells in having

Answer 1

A cytoplasm that lacks membrane-bound organelles

Their ribosomes are structurally smaller (70 S) in comparison to those found in eukaryotic cells (80 S)

No nucleus (instead they have a single circular DNA molecule that is free in the cytoplasm and is not associated with proteins)

A cell wall that contains peptidoglycan (a glycoprotein)

Question 2

In addition, many prokaryotic cells have a few other structures that differentiate the species from others and act as a selective advantage, examples of these are:

Answer 2

Plasmids
Capsules
Flagellum(eukrayotes can also have them sperm

Question 3

plasmids are

Answer 3

Plasmids are small loops of DNA that are separate from the main circular DNA molecule

Plasmids contain genes that can be passed between prokaryotes (e.g. genes for antibiotic resistance)

Question 4

Some prokaryotes (e.g. bacteria) are surrounded by a final outer layer known as a

Answer 4

capsule. This is sometimes called the slime capsule
It helps to protect bacteria from drying out and from attack by cells of the immune system of the host organism

Question 5

Flagellum (plural = flagella) are

Answer 5

long, tail-like structure that rotate, enabling the prokaryote to move (a bit like a propeller)
Some prokaryotes have more than one

Question 6

pili

Answer 6

For attachment to other cells or surfaces
involved in sexual reproduction

thread-like structures are polymers composed of covalently or non-covalently interacting repeated pilin subunits.

Question 7

Infolding of cell surface membrane

Answer 7

May allow photosynthesis or carry out nitrogen fixation

Question 8

prokaryotes always have

Answer 8

Cell wall , cell surface membrane, cytoplasm , circular DNA , ribosomes