Biology

Question 1

Name all SI prefixes and units

Answer 1

nano- 10–9
micro- 10–6
milli- 10–3
centi- 10–2
deci- 10–1
kilo- 103
mega- 106
giga- 109

Question 2

Name subcelluar structures of a eukaryotic (plant & animal) cell

Answer 2

a. cell membrane
b. cytoplasm
c. nucleus
d. mitochondrion
e. cell wall (plant only)
f. chloroplast (plant only)
g. vacuole (plant only)

Question 3

Name subcelluar structures of a prokaryotic (bacteria) cell

Answer 3

cell membrane
 cytoplasm
 cell wall
 chromosomal DNA/no ‘true’ nucleus
 plasmid DNA

Question 4

Structure and function of the nucleus (plural: nuclei)

Answer 4

STRUCTURE:
large membrane bound organelle (double membrane)
surrounded by nuclear envelope which contains pores
FUNCTION:
controls cell’s activities, contains instructions to make proteins - pores allow substances (e.g. RNA) to move between nucleus + cytoplasm

Question 5

Structure and function of the cytoplasm

Answer 5

STRUCTURE:
highly viscous (gel-like) substance enclosed within the cell membrane
FUNCTION:
contains enzymes responsible for breaking down waste and help in metabolic activity - also responsible for giving a cell its shape.

Question 6

Structure and Function of Cell membrane

Answer 6

STRUCTURE:
phospholipid bilayer with embedded proteins, is selectively permeable to ions and organic molecules
FUNCTION:
regulates movement of substances in and out of cell

Question 7

Structure and function of the mitochondrion

Answer 7

STRUCTURE:
double membrane - outer membrane covers the organelle - inner membrane folds over many times and creates layered structures called cristae, fluid in mitochondria is the matrix.
FUNCTION:
perform cellular respiration (has enzymes to do this)
where ATP is produced

Question 8

Structure and function of Cell wall (plants only)

Answer 8

STRUCTURE:
rigid structure made from cellulose fibres
FUNCTION:
give cell strength and structure, and to filter molecules that pass in and out of the cell.

Question 9

Structure and function of chloroplast (plants only)

Answer 9

STRUCTURE:
double membrane - inside the chloroplast are stacks of thylakoids - called grana - as well as stroma (the dense fluid inside)
FUNCTION:
Chloroplasts absorb sunlight - it’s the site of photosynthesis - some parts happen in the grana and others in stroma

Question 10

Structure and function of vacuole (plants only)

Answer 10

STRUCTURE:
membrane bound organelle - contains cell sap (weak solution of sugar + salts). Surrounding membrane called tonoplast
FUNCTION:
maintains internal pressure of cell + keeps it turgid (rigid)

Question 11

Describe the process of cells to organ systems and state an example

Answer 11

cells make up tissue, tissue makes up an organ, organs make up organ systems and organ systems make up an organism
EXAMPLES:
muscles (tissue), to heart (organ) to circulatory system (organ system)
lining of lungs (tissue), to lung (organ), to respiratory system (organ system)

Question 12

Name all the subcellular components of a bacteria cell

Answer 12

cell membrane
cytoplasm
cell wall
chromosomal DNA/no ‘true’ nucleus

Question 13

Structure and function of a cell membrane in a bacteria cell

Answer 13

STRUCTURE:

FUNCTION:
controls movement of substances in and out of cell

Question 14

Structure and function of cytoplasm in a bacteria cell

Answer 14

STRUCTURE:

FUNCTION:
where the functions for cell growth, metabolism, and replication are carried out

Question 15

Structure and function of a cell wall in a bacteria cell

Answer 15

STRUCTURE:
made up pf murein (a glycoprotein)
FUNCTION:
supports cells & prevents it changing shape

Question 16

Structure and function of the chromosomal DNA in a bacteria cell

Answer 16

STRUCTURE:
circular DNA, one long coiled-up strand
FUNCTION:
holds all of the vital information for the cell to survive

Question 17

Bacteria cells don’t have what?

Answer 17

A nucleus

Question 18

Compare eukaryotic and prokarotic cells

Answer 18

1 size: eukaryotic cells are larger prokaryotes
2 eukaryotes dont have cell wall (except plants + fungi), prokaryotes do
3 in eukaryotes, cytoplasm contains mitochondria (chloroplasts in plants) and ribosomes. prokaryotes have ribosomes present in cytoplasm (no mito… or chloro)
4 in eukaryotes, DNA is in nucleus, in prokaryotes, DNA found free in cytoplasm - additional DNA in rings of plasmid
5 eukaryotes divide by mitosis, prokaryotes divide by binary fission

Question 19

Structure and function of the plasmid DNA in a bacteria cell

Answer 19

STRUCTURE:
small, closed-circles of DNA present in cytoplasm
FUNCTION:
Unlike chromosomal DNA, plasmid DNA can move from one bacterium to another giving variation

Question 20

What are prokaryotic cells?

Answer 20

a unicellular organism that lacks a membrane-bound nucleus, mitochondria, or any other membrane-bound organelle e.g. bacteria cell