Biology Unit 2

Question 1

Explain why cells are the basic units of life

Answer 1

All chemicals and biomolecules are useless (on there own), unless they are organized together to form a cell; only then is life possible

Question 2

List the basic principles of the cell theory

Answer 2

1.) all organisms are made of cells
2.) cells are capable of self-reproduction
3.) cells can only come form preexisting cells

Question 3

Explain the Difference between the surface-area-to-volume ratio for large and small cells

Answer 3

Surface-area-to-volume: ratio of cell’s outside area to its volume; the relationship limits the maximum size of a cell
Large- has a reduced surface-area-to-volume ration, and the amount of diffusion of nutrients, wastes, and gases across the cell membrane is reduced
Small- are likely to have amore adequate surface area for exchanging nutrients and wastes

Question 4

Describe the fundamental components of a bacterial cell

Answer 4

Cell wall- usually present, with peptidoglycan
Plasma membrane
Ribosomes
(no nucleus or membrane-bound organelles)

Question 5

Identify the key differences between bacteria, acrhaea, and eukaryotes

Answer 5

Archaea and Bacteria are prokaryotes
Cell wall: usually present, no peptidoglycan (Archaea & Eukaryotes); usually present, with peptidoglycan (Bacteria)
Plasma Membrane: yes (ALL)
Nucleus: yes (Eukaryotes); no (Archaea & Bacteria)
Membrane-bound organelles: yes (Eukaryotes); no (Archaea & Bacteria)
Ribosomes: yes (all); eukaryotes are larger than prokaryotic