Cell Theory (22/9/16) Flashcards
What did Robert Hooke do? What was his limitation?
He observed dead cork - was the first to use the word “cell” to describe what he saw. His limitation was that he never observed anything living.
What did Anton van Leeuwenhoek do?
Observed living cells.
Which Kingdoms are eukaryotes/prokaryotes?
Eukaryotes: Protista, fungi, plantae and animalea.
Prokaryotes: Archea and monera.
What are cells?
The unit of structure and function for all living organisms.
Where do new cells come from and by what process?
Pre-existing cells - mitosis.
Describe the structure of a cell.
A plasma membrane that surrounds cytoplasm that contains organelles.
What are the two parts of a virus and what are they made of?
Capsid: made of proteins.
Core: made of DNA/RNA.
What does a viral capsid lack?
Membrane bound organelles, so a cell structure (plasma membrane, cytoplasm, organelles).
Define:
- viral replication
- viral reproduction
- the cell making copies of itself
- the making of the cells
Name three characteristics of a living cell which a viral capsid lacks.
- Self-reproduction
- Growth and maintenance
- The ability to ingest nutrients
Describe the viral replication of a DNA virus.
- DNA of virus inserted into host cell
- DNA of virus inserted into hosts DNA
- Host cell makes more viruses
Describe the viral replication of a retrovirus.
- RNA and reverse transcriptase into host cell
- Host cell makes viral DNA
- Viral DNA inserted into host cells DNA
- Host cell makes more viruses
Name four advantages of a LM.
- See true colours
- Easy preparation
- Can observe living structures
- Can observe entire cell/organism
What are the two types of EM’s and what are they used for?
- SEM - observe external structure
2. TEM - observe internal structure
Name four disadvantages of EM’s.
- Difficult and expensive preparation
- Specimen has to be dead
- Don’t see true colours
- Can only observe part of cell/organism
Name and define two advantages of EM’s.
- Greater resolution: the ability to distinguish between two nearby objects.
- Greater magnification: how big something appears to be.
What is the micrometer range for the plant and animal cells?
10 - 100 micrometers
What is the micrometer range for bacteria and organelles?
1 - 10 micrometers
What does the surface area of a cell correspond to?
The size of the cell membrane.
What does the size of the surface area of a cell determine?
The ability of the cell to meet it’s needs.
What does the volume of a cell correspond to?
They volume of the cytoplasm and organelles.
What does the size of the volume of a cell determine?
The needs and waste of a cell.
What are the four tissue types and what do they do?
- Muscle - movement
- Epithelial - protect
- Connective - connects, holds, transports
- Nervous - communication
What is the general order of the make up of an organism (smallest to biggest)?
cells - tissues - organs - organ systems - organisms.
What does the cell wall do?
Protects cell from bursting.
What does the plasma membrane do?
Regulates what goes in and out of the cell.
What is the mesosome?
The in-pocketing of the plasma membrane, which happens when a cell is about to divide.
What is the cytoplasm?
Fluid that surrounds organelles.
What do ribosomes do?
Protein synthesis for cell repair.
What is the nucleoid?
The region where the chromosome is found.
What is the flagella for?
Movement.
What is the Pili for?
Cell recognition.
What is fermentation?
The chemical breakdown of a substance by bacteria (release of CO2 and heat).
Name three examples of types of fermentation.
- Alcoholic
- Beutyric
- Lactic
What is photosynthesis?
The conversion of solar energy to chemical energy.
What is nitrogen fixation?
The conversion of atmospheric nitrogen into nitrates by soil bacteria.
Why is nitrogen fixation important?
It is the basic building blocks of all life forms.
Why would a TEM not be used to see chloroplasts?
Too small.
What are considered to be the main points of cell theory?
- Cells are made up of a plasma membrane that surrounds cytoplasm containing organelles.
- Cells self-reproduce by means of mitosis.
What are ribosomes? What is their purpose?
Protein synthesis - making protein to repair and grow cells.
What is the golgi apparatus and what is it’s purpose?
The destination for the endoplasmic reticulum, which serves as channels for the transportation and transformation of the proteins made by the ribosomes.
What is the ER’s purpose?
The ER is made up of membranes that serves as channels for the transportation and transformation of proteins made by ribosomes.
What is the mitochondrion’s purpose?
Cell respiration
Describe the nucleus.
A double membrane bound structure with pores, that contains DNA arranged in chromosomes.
Describe the rough endoplasmic reticulum.
Interconnected membranous sacs studded with ribosomes.
Describe the smooth endoplasmic reticulum.
Without ribosomes, smooth.
What is the lysosome?
A membrane bound vesicle containing enzymes produced in the golgi apparatus (so ER).
What is the purpose of the chloroplast?
It aids photosynthesis.
Describe prokaryote.
Unicellular: lack membrane-bound organelles.
Describe eukaryote.
Multicellular: have membrane-bound organelles.
Describe the DNA in a prokaryote.
Circular strand of naked DNA free in cytoplasm.
Describe the DNA in a eukaryote.
Coiled DNA forming proteins enclosed in the membrane-bound nucleus.
What type of ribosomes are in a:
- prokaryote
- eukaryote
- 70s
2. 80s
Describe the cytoplasm for a prokaryote.
The same cytoplasm, for everywhere.
Describe the cytoplasm for a eukaryote.
Compartmentalised cytoplasm by ER membranes.
What are the categories of classification (in order).
- Phylum
- Class
- Order
- Family
- Genus
- Species
What is a plastid?
Any form of small organelle in the cytoplasm of a plant cell.
What is a vacuole? Do plant or animal cells have vacuoles?
A space or vesicle in the cytoplasm of a cell, enclosed by a membrane and containing fluids. Plant cells have vacuoles, animal cells don’t.
What are centrioles?
A pair of organelles near the nucleus in an animal cell, involved in cell division.
Compare the shape of an animal and a plant cell.
Animal cell is loose, plant cell is rigid.
Compare the form of storage of an animal cell and a plant cell.
Animal cell stores in the form of glycogen, plant cell stores in the form of starch.
What type of cancer is treated with stem cell therapy?
Leukemia - stem cells from bone tissue.
What is the enzyme present in the RNA of a retrovirus?
reverse transcriptase
Define calibration.
The process of determining the actual distance between markings in an eyepiece.
What is the quality of stem cells called that makes them able to become any cell type?
Pluripotent.
What is the smallest organism observed with a LM?
Bacteria.
What are emergent properties?
Properties that arise from interaction of component parts.
What causes cells to die or divide?
SA:V is less than 1.
What is the type of protein associated with eukaryotic but not prokaryotic DNA?
Histone proteins.
What organisms have non-specialised cells?
Unicellular organisms.
What is the process by which stem cells become specialised?
Differentiation.
What is the process by which prokaryotic cells reproduce?
Binary fission.
What are acetabularia?
Huge cells.
What is a genetic disease treated by stem cell theory?
Stargadt’s, an auto immune disorder.
Name a disease that is an example of a retrovirus.
HIV.
What is the core material of a retrovirus?
RNA.
What is the measuring tool in an eyepiece called?
An optical micrometer.
What is the line on a micrograph used to measure size called?
Scalebar.
What is the type of stem cells that are the most controversial?
Embryonic stem cells.
What are bacteria cells attacked by?
Phage (bacteriophage).
What is the organelle whose inner membrane folds into grana?
Chloroplasts.
Name and describe three discrepancies to the cell theory.
- Skeletal muscle - are bigger with hundreds of nuclei.
- Giant algae - are huge but unicellular.
- Aseptate fungi - are made of long, undivided thread like structures of hypha with many nuclei.
What are stem cells?
Cells that commit to patterns but can still divide multiple times before they are no longer stem cells.
What is the equation for magnification calculations?
Mag = apparent size/actual size.
What is ultrastructure?
the detailed structure of the cell that was developed by the EM.
Describe binary fission.
The chromosome is replicated and moved to opposite ends of the cell. Then the wall and the plasma membrane are pulled inward and pinched apart to form to separate cells.
What is the specialised function of leukocytes?
Form pseudopods to “eat” bacteria and viruses.
What is the specialised part and it’s function in a red blood cell?
No nucleus - to allow space for haemoglobin (oxygen).
What is the specialised part and it’s function in a muscle cell?
Membranes between cells have been dissolved for rapid reaction for contraction.
What is the specialised part and it’s function in a sperm cell?
Flagella - to swim to fertilize egg.
What is the specialised part and it’s function in a fat cell?
Large vacuole to store fat.
What is the specialised part and it’s function in a osteocyte?
They are in bone tissue - so they receive materials to produce hard bone through canals called canaliculi.
What is the specialised function of a retinal cell?
Found in eyes - contains pigment that functions in low light situations.
What is the specialised function of an endocrine gland cell?
Produce hormones that get sent out in vesicles through the blood stream.
What is the specialised part and it’s function in a sclerenchyma cell?
A thick cell wall for strength to support plant.
What is the specialised part and it’s function in a root hair cell?
A large surface area for the absorption of water.
What is the specialised function of guard cells?
Found in leaves - regulate the movement of gases in/out of cell.
What is the specialised part and it’s function in a vessel element?
Lignin - makes it hard and resistant.
What is the specialised part and it’s function in a phloem cell?
A rough surface area for pollen to stick to pistol.
What is the process that takes place in chloroplasts?
Photosynthesis.
