Introduction to cells, tissues, and organs

Question 1

What are the tenets of the cell doctrine

Answer 1

• All living organisms are composes of one or more cells.
• Cell is the basic unit of structure and organization in organisms
• Cells arise from pre-existing cells

Question 2

Properties of protoplasm

Answer 2

• irritable (e.g. nerve cells)
• conductivity (take stuff from outside and react)
• contractility
• absorption and assimilation
• excretion and secretion
• respiration
• growth
• reproduction

Question 3

4 basic tissue type

Answer 3

1) epithelia
2) connective
3) nervous
4) muscular

Question 4

What is connective tissue derived from? And what does it produce?

Answer 4

Mesoderm

Extracellular matrix of fibers and ground substance

Question 5

What is nervous tissue developed from

Answer 5

Neuro-ectoderm

Question 6

What are the components of cytoskeleton within a cell

Answer 6

centrioles
microtubules
actin filaments
intermediate filaments

Question 7

Role of centrioles

Answer 7

Help with cell division, and help with formation of spindle fibers

Question 8

Role of microtubules

Answer 8

Help and support shape of cell, and also to help organelles move through cells

Question 9

Role of actin filaments

Answer 9

Muscle contraction, and cell signalling etc

Question 10

Role of intermediate filaments

Answer 10

provide mechanical support for plasma membrane where it comes into contact with other cells or extracellular matrix

Question 11

3 stages of endocytosis

Answer 11

• Invagination- substances bombard the membrane
• Adherence- membrane bends and fusogenic proteins collect at edges. The membrane fuses
• Fusion- vesicle pinched off

Question 12

3 stages of exocytosis

Answer 12

1) apposition- vesicles float upwards
2) adherence - hit plasma membrane, fusogenic proteins fuse to membrane
3) fusion- stuff is released

Question 13

How are proteins synthesized for secretion

Answer 13

• Signalling sequence present on peptide
• signal recognition peptide joins onto it
• both join on dock which sits on ER
• Finds translocon
• connection between recognition peptide and start of protein is lost
• ribosome released and protein enters membrane of ER
• Transported to Golgi and stored/secreted

Question 14

What is epithelia derived from?

Answer 14

One of the three germ layers (ectoderm, endoderm, and mesoderm)

Question 15

Types of endocytosis

Answer 15

phagocytosis (particles)

pinocytosis (fluids)

Question 16

Function of nucleolus

Answer 16

Produce rRNA

Question 17

Function of smooth ER

Answer 17

Lipid synthesis and transport of large molecules

Question 18

Function of Golgi body

Answer 18

Process, packs and sorts proteins received from ER

Question 19

Where is the lysosome produced?

Answer 19

ER and Golgi

Question 20

Role of peroxisome

Answer 20

Type of lysosome that converts hydrogen peroxide to water

Question 21

Role of proteasome

Answer 21

Degrades ubiquinated proteins

Question 22

Difference between nervous system and endocrine system

Answer 22

Nervous system
neurones, muscle - fast, short, local

Endocrine system
ductless glands- slow, prolonged action, widespread

Question 23

What’s membrane recycling?

Answer 23

Adding/removing membrane via endocrine/exocytosis using small vesicles which are free floating