cell types & specialisation

Question 1

what are the 3 key features of cells

Answer 1

• exterior plasma membrane separates cell from external medium
• nuclear region with DNA genetic material
• interior semifluid cytoplasm

Question 2

what are the 2 types of cell type

Answer 2

• prokaryotic
• eukaryotic

Question 3

describe the characteristics of prokaryotic cells

Answer 3

• bacteria
• no nucleus
• little internal organisation
• 0.5-2 um diameter

Question 4

describe the characteristics of eukaryotic cells

Answer 4

• distinct nucleus
• specialised internal organelles
• uni/multicellular
• 2-20 um diameter

Question 5

what is the most commonly encountered prokaryotes

Answer 5

Eubacteria

Question 6

what are the structural features of Eubacteria

Answer 6

• plasma membrane at edge of cytoplasm
• rigid peptidoglycan cell wall; gram-positive have only exterior cell wall, whilst gram-negative have extra outer membrane with periplasmic space
• relatively simple undifferentiated cytoplasm
• genomic DNA in ‘nucleoid’ region not separate from surrounding cytoplasm

Question 7

do plasmids contain DNA

Answer 7

YES

Question 8

describe the features of eukaryotes

Answer 8

• plasma membrane at edge of cytoplasm
• DNA contained in nucleus, separated from cytoplasm by membrane
• cytoplasm compartmentalised with membrane bound organelles with diverse functions
• complex cytoskeleton maintains cell integrity (e.g. microtubules/filaments)

Question 9

give 3 specialisations in prokaryotes

Answer 9

1. rotating flagella for movement
2. pili for attachment to surfaces/other bacteria
3. membrane folding for photosynthesis (Cyanobacteria)

Question 10

describe Archaea

Answer 10

• similar morphology to eubacteria
• found in hostile env
• proposed as 2 domains of like within eukaryotes

Question 11

features of animal cells

Answer 11

• nucleus
• mitochondria
• Golgi body
• peroxisomes
• RER
• SER
• chloroplasts

Question 12

features of plant cells

Answer 12

• nucleus
• mitochondria
• Golgi
• peroxisomes
• RER
• SER
• chloroplasts
• ribosomes
• cytoskeleton
• vacuole
• cellulose cell wall

Question 13

similarities eukaryotic and Prokaryotic cells

Answer 13

• plasma membrane
• similar mechanisms for transcription/translation of genetic info
• shared metabolic pathways
• similar photosynthetic mechanisms

Question 14

differences between eukaryotic and prokaryotic cells

Answer 14

• E has cell division via chromosomal separation but not P
• E has complex flagella, cilia & cytoskeleton system but not P
• E has complex membranous cytoplasmic organelles but not P

Question 15

how may the structure of eukaryotes differ according to movement

Answer 15

• flagella/cilia projections on surface = propulsion in protists/fungi + invertebrates (e.g. airways)

Question 16

how may the structure of eukaryotes differ according to metabolism

Answer 16

• adipose cells for fat storage
• large lipid droplet
• brown fat cells for heat production with mitochondria

Question 17

how may the structure of eukaryotes differ according to signalling

Answer 17

nerve cells have terminal dendrites + long axons for electric signals

Question 18

how many the structure of eukaryotes differ according to transport

Answer 18

RBC = biconcave + no nucleus or organelles when mature for more space for Hb + small/flexible

Question 19

how many the structure of eukaryotes differ according to reproduction

Answer 19

• sperm have flagella
• mushroom spores produced on gills from specialised ‘basidia’