Tushar 1.2

Question 1

Magnification

Answer 1

Is the degree of enlargement. Magnification = image size/ actual size

Question 2

Resolution

Answer 2

Ability of a microscope to distinguish two objects as separate

Question 3

Prokaryotic cell structure

Answer 3

No compartments and no membrane bound organelles + no nucleus

Question 4

Where is the DNA in prokaryotes

Answer 4

In cytoplasm, region of this is called nucleoid

Question 5

How is the DNA (chromosome) in prokaryotes

Answer 5

Don’t have histone proteins + single circular loop

Question 6

Things in prokaryotes

Answer 6

• ribosomes (70s)
• Cytoplasm
• Peptidoglycan cell wall
• Cell membrane
• circular DNA (chromosome)
• Plasmid (in some) - not linked to chromosome
• Flagellum (in some)
• Pilus (in some)

Question 7

Functions of flagellum and pillus

Answer 7

Flagellum - allows cell to move

Pili - can connect to other bacterial cell so genetic material could be exchanged

Question 8

How do prokaryotes divide

Answer 8

Binary fission

Question 9

Function of cell wall and cell membrane

Answer 9

Cell wall: prevents bursting, provide support+ strength, maintains shape

Cell membrane: controls what enters and leaves the cell

Question 10

Where do chemical reactions happen in prokaryotes

Answer 10

Cytoplasm as not compartmentalised

Question 11

What are plasmids

Answer 11

Circular DNA molecules that can help the cell adapt to environment changes - carry antibiotic resistant genes

Question 12

Eukaryotic cell strucutre

Answer 12

Compartmentalised, membrane bound organelles, have nucleus with DNA associated with proteins (histones)

Question 13

Benefits of compartmentalisation in cells

Answer 13

• more efficient as can concentrate required components at specific places
• substances that cause damage can be kept inside organelle
• opt pH can be maintained inside organelles
• organelles with contents can be moved within cells

Question 14

All main organelles (11 of them)

Answer 14

• nucleus
• rER
• golgi apparatus
• sER
• lysosomes
• free ribosomes
• mitochondria
• chloroplast
• vacuole
• centrosomes (+ microtubules)
• cilia and flagella

Question 15

Different cell walls

Answer 15

bacteria : peptidoglycan
fungi : chitin
plants : cellulose
animals : none; have extracellular matrix

Question 16

What is extracellular matrix and use

Answer 16

a network of collagen fibres, glycoproteins,… that provides support to the cells and allows cells to communicate with each other

Question 17

Plant vs animal cells

Answer 17

Plant cells have (which animals dont)

• cell wall
• chloroplasts
• large central vacuole (animal cells sometimes have small vacuoles)

Carbs stored as starch in plants, glycogen in animals
No centrioles in plant cells (only centrosomes)
Plant cells have no cholesterol in their membranes

Question 18

Exocrine gland cells of pancreas (acinar cells)

Answer 18

• produce digestive enzymes
• have rER, ribosomes, golgi, to produce and modify these proteins
• have nucleus, cell membrane, lysosomes as well
• Specialised organelle: zymogen granule (sort, package, secrete digestive enzymes)

Question 19

Palisade mesophyll cells

Answer 19

Carry out most of photosynthesis
Lots of chloroplasts
Cell wall, membrane, large vacuole, mitochondria, nucleus