Cells and Tissues

Question 1

Organelles and specialisations expected in a secretory cell

Answer 1

Lots of:

• rER
• Golgi Apparatus
• Mitochondria

Question 2

Organelles and specialisations expected in absorpative cell

Answer 2

Lots of:

• Mitochondria
• Microvilli
• Cell junctions

Question 3

Responsibilities of cytoskeleton

Answer 3

Maintenance of cell’s shape and movement

Question 4

Components of cytoskeleton

Answer 4

• Microfilaments
• Intermediate filaments
• Thick filaments
• Microtubules

Question 5

Identify main component of Microfilament and its role

Answer 5

Actin; Forming contractile skeleton; regulating cell shape and tactile activity

Question 6

Intermediate Filaments

Answer 6

Vibramentin or Cytokeratin - Keeping organelles in place and anchoring them to the cell membrane

**ALSO DESMIN AND LAMININ

Question 7

Microtubules

Answer 7

Responsible for positioning of organelles and cell shape changes. Used in centrioles in cell division and cilia formation

Question 8

Cilia

Answer 8

Extensions of the microtubule cytoskeleton that actively move

Question 9

Microvilli and what they consist of

Answer 9

Extensions of the actin microfilament cytoskeleton, no active movement; role is to increase surface area

Question 10

Structure of Cilia and how this causes movement

Answer 10

9 Pairs of microtubules surrounding a core pair. Each is attached to the next one and the core. They attach and detach at the same time to cause a beating

Question 11

What are Centrioles made of

Answer 11

groupings of microtubules arranged in a 9 (triplets) + 0 pattern

Question 12

Tight/Barrier/Occluding Junction

Answer 12

Prevent the passage of substances between cells and helps maintain position of membrane proteins

Question 13

Adherens Junction/Zonula Adherens

Answer 13

Extension of actin cytoskeleton and attaches adjacent cells together to form a structural sheet

Question 14

Desmosomes

Answer 14

Extension of intermediate fillament cytoskeleton and attaches adjacent cells together to form a structural sheet
(Like Zonula Adherens)

Question 15

Difference between Desmosomes and Zonula Adherens

Answer 15

Adherens Junctions are made of actin/microfilaments while Desmosomes are made of intermediate filaments

**BOTH HAVE CADHERENS I THINK

Question 16

Hemidesmosomes

Answer 16

Anchoring junctions attach epithelia to basement membrane and hence tissue beneath (e.g. skin)

Question 17

What are Hemidesmosomes made of

Answer 17

Integrins

Laminin collagen

Question 18

Gap junctions and what does it permit

Answer 18

For direct communication - Passage of ions, amino acids, sugars, second messangers, metabolites

Permits coordinated cell activity - e.g. heart/muscle

Question 19

What are Gap Junctions made of

Answer 19

Connexins which assemble into connexons

Question 20

Junctional Complex Orientation

Answer 20

Top to Bottom:

• Occluding
• Adherent
• Desmosomes
• Gap Junction

OADG

Question 21

4 Basic tissue types

Answer 21

• Epithelium
• Connective Tissue
• Muscle
• Nerve

Question 22

3 Germ Layers

Answer 22

• Ectoderm
• Mesoderm
• Endoderm

Question 23

Epithelia

Answer 23

Sheets of closely packed cells derived of any of the 3 germ layers which cover a surface

Question 24

Connective tissue and which germ layer is it derived from

Answer 24

Cells dervied from mesoderm and producing an extracellular matrix of fibres

Question 25

Which germ layer are muscular tissues derived from

Answer 25

Derived from mesoderm and composed of cells whose cytoplasm contains filaments made of contractile proteins

Question 26

Which type of germ layer are nervous tissues derived from

Answer 26

Develop from neuro-ectoderm and consist of cells of which the main type possesses processes called neurites which conduct impulses when stimulated