Topic 1: Cell Biology Flashcards
(22 cards)
The cell theory states that…
- all living things are composed of cells
- the cell is the smallest unit of life
- cells come from pre-existing cells
What are some examples that question the cell theory?
Striated muscle
Aseptate fungal hyphae
Giant Algae
What. are the 7 functions of life?
MR H GREN Metabolism Reproduction Homeostasis Excretion Nutrition Growth
Investigate the functions of life in the Paramecium
They are surrounded by cilia which allows it to move
They engulf food through vacuoles containing enzymes for digestion
Waste is taken out through an anal pore
Gases enter and exit through diffusion
They divide asexually
What happens if the volume of a cell increases faster than its surface area
A decrease in SA to V ratio
What increases SA to V ratio
cells and tissues that are specialized for gas or material exchanges because in order to optimise material transfer, this will increase its area
How do you calculate magnification
Image size (with the ruler) divided by actual size (scale bar)
How do you calculate the actual size
Image size (with ruler) divided by magnification
What are emergent properties
When the interaction of an individual component produces new functions
EX) cells are grouped to form tissues… organs formed from function of multiple tissues…etc
What is differentiation
The process during development when newly formed cells are more specialized and different from one another as they mature
How does a cell diffrentiate
Due to the activation of different genes within a given cell through chemical signs
What are active genes
They are packaged in an expanded form that is accessible to transcriptional machinery
What are inactive genes
They are typically packaged more condensed which saves space and is not transcribed
What happens to a cell when it diffrentiates
It loses its capacity to form alternative cell types
What are stem cells
Unspecialized cells that have two qualities…
Self renewal and potency
What is potency
The capacity to differentiate into specialized cell types
What is self renewal
Continuously dividing and replicating
What are stem cells used for
To replace damaged or diseased cells with healthy functioning ones
What are some examples of stem cell therapy
Stargardt’s disease (vision loss)
Parkinson’s disease (disorder of central nervous system)
Leukemia (result of chemotherapy)
Examples of Stem cells
Bone marrow (for leukemia)
Skin cells (burn victims)
Islet cells (diabetes)
Myocardium (heart disease)
Retinal cells (blindness)
Nerve cells (parkinson’s)
What are three sources that stem cells can be derived from
embryos
umbilical cord
certain adult tissues like bone marrow
Ethical considerations associated with therapeutic use of stem cells
- Using adult tissue may be effective for some conditions. but limited scope of application
- when taken from umbilical cord, blood needs to be served and preserved which raises issue of access and availability
- when stem cells taken from embryos, requires destruction of a potential life
