1.1 Intro To Cells

Question 1

Striated muscle what idea does it challenge

Answer 1

Challenges idea that cells are small and contain one nuclei each
(Multinucleated from fusion; as long as 300mm)

Question 2

Giant algae (acetabularia)

Answer 2

Challenges idea that cells must be small
(Up to 100mm diameter; 1 nucleus)

Question 3

how does aseptate fungal hyphae challenge the cell theory?

Answer 3

Challenges that cells form basic units of life
(Long uninterrupted structures with numerous nuclei)

Question 4

MERIGRAN

Answer 4

movement
Excretion
Respiration
Irritability (response to stimuli)
Growth
Reproduction
Adaptability (regulation due to external changes)
Nutrition (obtaining)

Question 5

Paramecium movement

Answer 5

Wave action of cilia on cell membrane allows for movement

Question 6

Paramecium excretion

Answer 6

cell membrane regulates the movement of molecules in and out of the cell, including the expulsion of metabolic wastes

Question 7

Paramecium respiration

Answer 7

mitochondria present within paramecium to facilitate cellular respiration

Question 8

Paramecium irritability (response)

Answer 8

proteins present on cell membrane help detect when contact is made with food (yeast, bacteria, etc) and cilia sweeps food towards the cell mouth

Question 9

Paramecium growth

Answer 9

Assimilates nutrients from food for growth

Question 10

Paramecium reproduction

Answer 10

Via binary fission

Question 11

Paramecium adaptability

Answer 11

Contractile vacuoles can take in and expel water to maintain osmotic potential within the cell

Question 12

Paramecium adaptability

Answer 12

Contractile vacuoles can take in and expel water to maintain osmotic potential within the cell

Question 13

Paramecium nutrition

Answer 13

ingestion of food at cell mouth via phagocytosis and the formation of food vacuoles

Question 14

Chlamydomonas movement

Answer 14

presence of flagella allows for movement towards light

Question 15

Chlamydomonas excretion

Answer 15

cell membrane regulates the movement of molecules in and out of the cell, including the expulsion of metabolic wastes

Question 16

Chlamydomonas respiration

Answer 16

mitochondria present within cell to facilitate cellular respiration

Question 17

Chlamydomonas irritability (response)

Answer 17

Contains an eyespot, an organelle reponsible for light detection

Question 18

Chlamydomonas growth

Answer 18

assimilates nutrients from photosynthesis and environment for growth

Question 19

Chlamydomonas reproduction

Answer 19

via mitosis

Question 20

Chlamydomonas adaptability

Answer 20

Contractile vacuoles can take in and expel water to maintain osmotic potential within the cell

Question 21

Chlamydomonas nutrition

Answer 21

carries out photosynthesis via chloroplasts

Question 22

Two main constraints to cell size

Answer 22

• Large enough to store genetic material, resources (nutrients) and cellular structures that allows for efficient adaptation to life on earth
• Small enough to maintain a high surface area to volume ratio for rapid exchanges of molecules with the external cellular environment

Question 23

Adaptations for high SAVr (4)

Answer 23

• Cell division (increase cell numbers)
• Compartmentalisation due to presence of membrane bound organelles
• Folding of cell membrane (e.g. microvilli and crista in mitochondria)
• Extensions (root hair cell)

Question 24

What is an emergent property?

Answer 24

an emergent property is a property arising from the combined effort of multiple specialised cells that enables the organism to carry out complex functions of life

Question 25

Caenorhabditis elegans (emergent property) 4

Answer 25

• almost 1/3 are nerve cells for coordination and response
• muscle calls aid in locomotion by contraction to allow the organism to move via wriggling
• presence of MandF repro cells
• movement, distinct anus and intestinal cells aid in digestion

Question 26

how are genes expressed in cell specialisation?

Answer 26

some genes are expressed and others are not expressed (signals are sent to cells to deactivate and activate certain genes to form specialised cells)

Question 27

how does cell differentiation arise?

Answer 27

• some genes are expressed and others are not expressed
• diff types of proteins are synthesised
• thus cell differentiation

Question 28

stem cell def

Answer 28

undifferentiated cells that can replicate and have the ability to differentiate into specialised cell types

Question 29

what are totipotent stem cells?

Answer 29

stem cells that can differentiate into any cell type (incl early embryonic cell types)

Question 30

pluripotent stem cells

Answer 30

can differentiate into any cell type found in human body (but not early embryonic or extra-embryonic cell types)

Question 31

multipotent stem cells

Answer 31

can differentiate to related cell types (Eg. cord blood cells –> rbc, wbc)

Question 32

unipotent stem cells

Answer 32

can dev into one specific cell lineage or cell type

Question 33

what is Stargardts disease

Answer 33

• a form of macular degeneration
• gradual loss of vision starting from central vision

Question 34

how do genes lead to Stargardt’s disease?

not needed to know in such detail

Answer 34

• recessive inherited genetic condition, mutant form of ABCA4 –> codes for a ATP dependent transporter protein found in cellular membranes, responsible for transport of harmful byproducts of processes that uses retinol (from vitamin A) to prod visual pigments.
• poor transport of harmful byproducts –> accumulation in cells –> degenerate of the macula

Question 35

stargardts disease: treatment 3

Answer 35

• involves inducing embryonic stem cells to differentiate into retinal cells
• these are injected into the retina, they attach and become fully functional
• vision restored in time
  (treatment still in clinical trials stage)

Question 36

what is leukaemia

Answer 36

*⁠ ⁠blood cancer of WBCs
*⁠ ⁠⁠excessive production of abnormal WBCs
*⁠ ⁠⁠leads to crowding out of other blood cells
*⁠ ⁠⁠thus disrupts proper body function

Question 37

leukaemia treatment 4

Answer 37

• involves use of HSC (hematopoietic stem cells)
• cancerous bone marrow removed via combo of surgery, chemotherapy, radiotherapy
• HSC harvested and purified from donor bone marrow/cord blood
• HSC transplanted within diseased bone marrow region –> cells differentiate and repopulate by turning into the necessary blood cells

Question 38

why are adult stem cells hard to extract?

Answer 38

adult stem cells are hard to find and isolate

Question 39

why is the use of embryonic stem cells seen to be unethical? (as compared to cord blood and adult stem cells)

Answer 39

• recognition of an embryo as a human with rights –> extraction will result in the death of the embryo (prevention of maturation)

Question 40

potential range of use: embryonic vs cord blood vs adult stem cells

Answer 40

embryonic stem cells have the greatest potential for use due to its pluripotency

white cord blood cells/adult stem cells –> multipotent at best

Question 41

arguments FOR use of embryonic stem cells 3

Answer 41

• can cure serious ailments and diseases that cannot be cured otherwise
• ESC donated by parents for sci use –> would have been lost anyway (abortion/IVF leftovers)
• cells from embryos do not have nerves –> cannot feel pain / think

Question 42

arguments AGAINST use of embryonic stem cells 5

Answer 42

• involves destruction of human life (what stage is an embryo considered a human being?)
• potential wastage - excess embryos destroyed
• religious and moral arguments - man playing god
• greatly incr chance to cont. division, turn into cancerous cells
• greater research - alt means can be discovered

Question 43

um to cm

Answer 43

um /10k