2 Cell types & specialisation

Question 1

3 essential features of a cell.

Answer 1

1 Exterior plasma membrane - seperates cell from external medium.
2 Nuclear region with DNA genetic material.
3 Interior semifluid cytoplasm.

Question 2

Two main cell groups:

Answer 2

Prokaryotic & Eukaryotic.

Question 3

Prokaryotic:

Answer 3

No nucelus. Little internal organisation.

Question 4

What organisms are prokaryotic?

Answer 4

Bacteria & Archaea.

Question 5

Prokaryotic cell size:

Answer 5

0.5-2um in diameter.

Question 6

Eukaryotic:

Answer 6

Distincy nucleus. Specialized internam organs. Uni or multicellular.

Question 7

Eukaryotic cell size:

Answer 7

5-20um in diameter

Question 8

5 Bacteria features:

Answer 8

1 Plasma membrane at edge of cytoplasm.
2 Rigid peptidoglycan cell wall - gram pos have only exterior cell wall. Gram neg have extra outer membrane with periplasmic space.
3 Relatively simple, undifferentiated cytoplasm.
4 Genomic DNA in ‘nucloid’ region not seperate from surround sytoplasm
5 DNA containing plasmids.

Question 9

Gram positive vs gram negative.

Answer 9

Pos: thick peptidoglycan cell wall. Stains purple. No outer membrane. Susceptible to antibiotics.
Neg: thinner layer of peptidoglycan cell wall. Stains pink. Outer membrane of LPS.

Question 10

Bacteria organelles: (3 points)

Answer 10

Flagella for movement.
Fibriae & pili for attachment to surcases/other bacteria.
Cyanobacteria have memebrane foldings for photosynthesis.

Question 11

Archaea:

Answer 11

Found in hostile environments. Eukaryotes evolved from acheaea.

Question 12

4 Eukaryotic features:

Answer 12

1 Plasma membrane at edge of cytoplasm.
2 DNA contained in nucleus, seperated from cytoplasm by membrane.
3 Cytoplasm compartmentalised with membrane bound organelles diverse functions.
4 Complex cytoskeleton maintains cell integrity (microtubules & filaments).

Question 13

What organisms are eukaryotic?

Answer 13

Animals and Plants

Question 14

Animal cells:

Answer 14

Nuclues. Plasma membrane. Nucleolus. Lysozyme. Mitochondira. Golgi body. Peroxisomes. RER. SER. Small vacuoles. Ribosomes. Centrioles. Cytoskeleton.

Question 15

Plant cells:

Answer 15

Nuclues. Nucleolus. Leukoplast. Plasmodesmata. Plasma membrane. Mitochondira. Golgi body. Peroxisomes. RER. SER. Chloroplasts. Ribosomes. Cytoskeleton. Single large vacuole. Rigid cellulose cell wall.

Question 16

Shared features in Eukaryotic and Prokaryotic cells: (7 features)

Answer 16

1 Similar plasma membrane.
2 DNA for genetic information with indentical code.
3 Transcription and translation with similar ribosomes.
4 Metabolic pathways (glycolysis & TCA).
5 Similar apparatus for conservation of chemical energy as ATP.
6 Similar photosynthesis.
7 Similar mechanism for synthesizing & inserting membrane proteins.

Question 17

Features only in eukaryotes: (10 features)

Answer 17

1 Divsion of cells into nucleus and cytoplasm. Seperated by a nuclear enevelope containing complex pore structures.
2 Complex chromosome composed of DNA and associated proteins that are capable of compacting into mitotic structures.
3 Complex membranous cytoplasmic organelles (ER, Golgi complex, lysosomes, endosomes, perioxisomes and glycoxisomes).
4 Mitochondria for respiration
5 Chlroplasts for photosynthesis.
6 Complex cytoskeletal system - microtubules, intermediate filaments and microtubules.
7 Complex flagelle and cilia.
8 Pinocytosis, receptier mediated endocytosis and phagocytosis
9 Plants have cellulose containg cell walls.
10 Cell divison using a microtubule-containing mitotic spindle that seperates chromosomes.

Question 18

Multicellularity allows ____________

Answer 18

Cell specialisation.

Question 19

Movement structures:

Answer 19

Flagella and Cilia projections on surface allow proplulsion in portists/fungi.
Also, has roles in vertbrates in ears and airways.

Question 20

Photosynthesis structures:

Answer 20

Chloroplasts concentrated in plant cells exposed to light.

Question 21

Metabolism structures:

Answer 21

Adipose cells for fat storage - large lipid droplet.
Brown fat cells fopr heat production with mitochondria.

Question 22

Signalling structures:

Answer 22

Nerve cells have terminal dendrites and long axon for electric signals.ra

Question 23

Transport structures:

Answer 23

Erythrocytes specialised for gas transport (no nucleues or organelles when matured). Full of haemoglobin. Small & flexible.

Question 24

Reproduction structures:

Answer 24

Sperm have flagellum. Mushroom spores produced on gills from specialised basidia.