Question

7. mem 8. struc 1. Most prokaryotes range in size from 0.5 to 2.0 pm, yet have large surface-to-volume ratios. This large surface-to-volume ra- tio allows prokaryotes to: (a) Ward off invaders (b) Resist antibiotics (c) Get nutrients easily to all parts of the cell (d) Undergo meiosis (e) b and d 2. Attribute each of the following to either P, prokaryotes only; E, eukaryotes only; B, both; N, neither: (a) —Single chromosome (b) __Membrane-bound nucleus (c) __Fluid-mosaic membrane (d) _Viruses (e) ___70S ribosomes (f)_Endoplasmic reticulum _Respiratory enzymes in mitochondria (h) Mitosis _Peptidoglycan in cell wall Cilia _80S ribosomes Chloroplasts. (m) "9+2" microtubule arrangement in flagella (n) __Bacteria (0) Can have extrachromosomal DNA p_Meiosis (i) P . SEBE 3. Match the following bacterial morphology designations with their description: Coccus (a) Rod-shaped Bacillus (b) Grapelike clusters Spirillum (c) Round spheres Vibrio (d) Corkscrew shaped Staph (e) Cube of 4 cells Tetrad (f) Curved rods

Answer 1

Question 1: Get nutrients easily to all parts of the cells ( Option C )

In prokaryotes large surface to volume ratio ensures that available nutrients are easily diffused into cells. Also, any waste product produced can be easily diffused out. As the cell size gets bigger it become less efficient, to overcome this challenge either cell divides or other organelles are developed as in case of eukaryotes.

Question 2:

a: Prokaryotes: Single chromosomes

b: Eukaryotes: Membrane bound nucleus

c: Both: Fluid mosaic membrane

d: Neither: Viruses

e: Prokaryotes: 70s ribosomes

f: Eukaryotes: Endoplasmic reticulum

g: Eukaryotes: Respiratory enzyme in mitochondria

h: Eukaryotes: Mitosis

i: Prokaryotes: Peptidoglycan in cell wall

j: Eukaryotes: Cilia

k: Eukaryotes: 80s ribosomes

l: Eukaryotes: Chloroplast

m: Eukaryotes: “9+2” microtubule arrangement in flagella

n: Prokaryotes: Bacteria

o: Both: Can have extrachromosomal DNA

p: Eukaryotes: Meiosis

Most prokaryotes contain one circular chromosome. Non-essential genes are stored outside of chromosome that is in plasmids.

Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus that holds genetic material as well as membrane-bound organelles.

All prokaryote and eukaryote cells have plasma membranes. The plasma membrane is composed primarily of proteins and lipids. The lipids occur in two layers (a bilayer). Proteins embedded in the bilayer appear to float within the lipid, so the membrane is constantly in flux. The membrane is therefore referred to as a fluid mosaic structure.

All prokaryotes have 70S (Svedberg units) ribosomes while eukaryotes contain larger 80S ribosomes in their cytosol. The 70S ribosome is made up of a 50S and 30S subunits.

Prokaryotes, such as bacteria, do not have a nuclear membrane surrounding their cellular DNA, so cell division is happens differently than in eukaryotes. It usually occurs by binary fission.

Peptidoglycan, also called murein, is a polymer that makes up the cell wall of most prokaryotes. It is made up of sugars and amino acids, and when many molecules of peptidoglycan joined together, they form an orderly crystal lattice structure.

In prokaryotes, nonviral extrachromosomal DNA are primarily found in plasmids whereas in eukaryotes extrachromosomal DNA are primarily found in organelles.

Question 3:

Coccus: Round Sphere (c)

Bacillus: Rod shaped ( a)

Spirillum: Corkscrew shaped (d)

Vibrio: Curved rods (f)

Staph: Grapelike Clusters (b)

Tetrad: Cube of 4 cells (e)