Biology (Cells) End of Year Exam Grade 9 Flashcards
Types of cells
Animalia, Fungi, Eubacteria, Plantea, Protists, Archaebacteria.
All organisms are…
are composed of either prokaryotic or eukaryotic cells.
Prokaryotes
No nucleus
DNA is naked
Unicellular
Smaller (1-5 micrometers)
Eukaryotes
Has nucleus
DNA is bound to protein
(DNA is wrapped around histone proteins. This helps organize the massive amount of DNA packed within each chromosome.)
Unicellular and multicellular
Larger(10-100 micrometers)
Both prokaryotes and eukaryotes
DNA
Cell membrane
Ribosomes (make protein)
Antibiotics
Medicine used against bad bacterial infections.
Probiotics
Promote good bacteria in your body.
Levels of organization
Cells - Tissues - Organs - Organ System - Organisms
Nerve cells
They use electrical and chemical signals to send information between different areas of the brain, as well as the spinal chord and the entire body.
Stem cells
Unspecialized unique cells of the body that have the ability to develop into several different types of cells.
Types of stem cells
Embryonic stem cells
Cord blood stem cells
Adult stem cells
Embryonic stem cells
+ can differentiate into any type in body (pluripotent)
- destruction of potential living things
- more risk of developing into tumor
Cord blood stem cells
+ no ethical problem
+ easy to obtain and store
- limited capacity to differentiate
Adult stem cells
+ you receive consent
+ removal does not kill adult
+ less chance of malignant tumor
- limited differentiation (multipotent)
- difficult to obtain
Example of stem cell therapy
Stargardt’s disease. - causes vision loss
Parkinsons disease - degenerative disorder
Substances that need to move in and out of cells
Iron, oxygen, carbon dioxide, glucose and protein.
Types of passive transport
Diffusion and osmosis
*no energy is required for passive transport
Diffusion
Randomized movement
High - low concentration
Osmosis
Movement of water molecules
Influenced by concentration of solute
Cell membrane
Semi-permeable: lets certain things in and keeps other things out.
Types of solutions
Hypertonic, hypotonic, and isotonic
Hypertonic
water will move out (the cell becomes dehydrated and shrinks)
*moves out to try to balance the amount of H20
Hypotonic
water will move in (the cell will expand and possibly burst)
*Moves in to try and balance the H20 to the solute
Isotonic
water will move in and out - equal movement (cell/tissue stay the same)
Osmolarity
concentration of solute
Organ transplants
Osmosis in real life
To transport organs you need to transport in isotonic solution so it does not shrink or swell.
IV solutions
You are hooked up to IV to keep the person hydrated.
There is salt in the solution so it is a isotonic solution not a hypotonic solution.
Cellular respiration
A series of reactions/processes that take place in cells or organisms to convert chemical energy in oxygen and nutrients to (ATP) energy
C6H12O6 + 6O2 - 6CO2 + 6H2O + ATP
Glucose + Oxygen - Carbon dioxide + water + energy
ATP
is a high energy molecule that functions as an immediate source of energy cells
Some processes that need (ATP) energy
Movement
Active transport
Growth (cell division)
For your neurons to send signals
Digestion
Aerobic respiration
Happens in mitochondria to yield large amount of ATP.
*oxygen is needed
*much of the process occurs in the mitochondria (powerhouses of the cell)
Anaerobic respiration
Happens outside the mitochondria in the cytosol and yields small amounts of ATP when no oxygen is present.
*Animals: Glucose (reactant) - Lactid acid (product) + small amount of ATP
*Plants and yeast: Glucose - Ethanol +Carbon dioxide + energy (ATP)
Differences between Anaerobic and Aerobic respiration
Generates less amount of ATP in anaerobic and more aerobic
Occurs in different places in the cell
Oxygen is needed in one and not the other.
Example of fermentation
Bread goes through alcoholic fermentation which contributes to the production of ethanol. In bread, yeast and bacteria convert sugars into carbon dioxide, causing the dough to rise.
Functions of life
Reproduction - living things produce offspring, either sexually or asexually
Excretion
Nutrition
Homeostasis
Metabolism
Sensitivity
Growth
Endosymbiotic theory
Ancestral prokaryotes - infolding of plasma membrane - endosymbiosis
*Ancestral eukaryote (how eukaryotic cells formed)
Smaller prokaryotes were engulfed by larger prokaryotes uniting to become more complex
Viruses
can reproduce only by infecting living cells
Not considered to be living (a non living particle)
Have DNA or RNA
Cycle of a virus
(Lytic infection)
Viral genes are transcribed by the host cell
The bacterium makes new viral proteins and nucleic acid
The proteins and nucleic acid assemble into new viruses
New viruses escape and infest other cells.
Examples of viral infections
Covid 19
Pneumonia
Microscopes
Light microscope - light is used
Electron microscope - higher magnification and more expensive
M = Magnification
M = size of image (I)/actual size of specimen (A)
