3. basics of cytology
TRANSCRIPT
Basics of cytologyBIOLOGY OF THE CELL ...Life begins with cells
Progenitor cells2
3
4
One creator ... One Grand Designer5
The Cell6
Fundamental / Basic subunit of life First verified by Robert Hooke by examining a CORK Cellulae (Latin for small rooms) Cell theory
By Matthias Schleiden and Theodor Schwannall organisms are composed of one or more cells (basic unit of life); cells arise from pre-existing cells
Diversity and Commonality7
Morphology Ability to move Stability of structures Metabolic activities and requirements Multicellularity vs. Colony formation in unicellular
organisms Internal organization
Prokaryotic Eukaryotic
Diversity and Commonality8
Eubacteria (with rapidly dividing cells) Lactococcus lactis Used to produce cheese such as Roquefort, Brie, and
Camembert.
Diversity and Commonality9
A mass of archaebacteria Methanosarcina produce their energy by converting carbon dioxide
and hydrogen gas to methane Some species that live in the rumen of cattle give rise to >150 liters of methane gas/day
Diversity and Commonality10
Blood cells Erythrocytes Leukocytes Thrombocytes
Diversity and Commonality11
Large single cells: fossilized dinosaur eggs
Diversity and Commonality12
A colonial single-celled green alga Volvox aureus The large spheres are made up of many individual
cells, visible as blue or green dots The yellow masses inside are daughter colonies, each made up of many cells
Diversity and Commonality13
Purkinje neuron of the cerebellum Can form more than a hundred thousand connections
with other cells through the branched network of dendrites Made visible by introduction of a fluorescent protein Cell body is the bulb at the bottom
Diversity and Commonality14
Cells can form an epithelial sheet, (slice through
intestine shown here. Each finger-like tower of cells) A villus, contains many cells in a continuous sheet
Diversity and Commonality15
Plant cells are fixed firmly in place in vascular plants supported by a rigid cellulose skeleton Spaces between the cells are joined into tubes for
transport of water and food.
Diversity and Commonality16
What is a cell?1. Degree of organization1. 2. Multicellular Unicellular
2. Ability to exchange materials with their surroundings 3. Ability to transform energy 4. Ability to grow 5. Ability to reproduce independent progeny (offspring)
Basic parts1. 2. 3. Cytoplasmic /plasma membrane Nuclear region Cytoplasm
Prokaryotic cellCytoplasmic membrane
Selective Semi-permeable Bi-lipid
Functions:ETC DNA synthesis & Cellular reproduction Secretion of intracellular enzymes Nutrient transport (simple diffusion, osmosis, active transport) Cell wall synthesis Chemotaxis
Eukaryotic cellCytoplasmic membrane
Selective Semi-permeable Bi-lipid
Functions:Secretion of intracellular enzymes Nutrient transport (simple diffusion, osmosis, active transport) Cell wall synthesis Chemotaxis Endocytosis
Prokaryotic cellNuclear Region Genetic material DNA Called nucleoid (not bound by a membrane)
Eukaryotic cellNuclear Region Genetic material DNA Membrane-bound
Prokaryotic cellCytoplasm Everything contained within the cytoplasmic membrane except the nuclear region Contains ribosomes & sometimes plasmids No membrane bound organelles Contains inclusions/inclusion granules
Eukaryotic cellCytoplasm Everything contained within the cytoplasmic membrane except the nuclear region Contains ribosomes Membrane bound organelles:Mitochondria Chloroplasts Endoplasmic reticulum Golgi membranes / apparatus Cytoskeleton
Prokaryotic cellAdditional structures Cell wall Capsule; Glycocalyx; Slime layer; S layer Fimbriae and Pili Flagella Axial filaments Endospore
Prokaryotic vs. Eukaryotic27
Prokaryotic vs. Eukaryotic28
Prokaryotic vs. Eukaryotic29
Prokaryotic vs. Eukaryotic30
31
Phospholipid bilayer32
Molecules of Cells33
34
35
36
37
38
39
Mitosis40
Prophase - chromatin condenses, nucleoli
disappear, sister chromatids are visible, spindle begins to form as centrosomes move away from one another.
Mitosis41
Prometaphase - nuclear envelope fragments,
spindle increases in size and spread, microtubules from one side of the spindle attach to the kinetochore of one of the sister chromatids, while microtubules from the other side of the spindle attach to the kinetochore of the othe sister chromatid.
Mitosis42
Metaphase - chromosomes line up, single file, on the
metaphase plate (an imaginary line in the middle of the cell)
Mitosis43
Anaphase - sister chromatids uncouple and pull
apart, one sister chromatid (now called a full-fledged "chromosome"!) moves towards one side ("pole") of the cell, while the other sister chromatid moves towards the other side. Microtubules attached to the kinetochores of each chromosome shorten, thereby pulling the chromosomes poleward. Microtubules that are NOT attached to kinetochores lengthen, thereby elongating the cell.
Mitosis44
Telophase - daughter nuclei begin to form, DNA
begins to "de-condense".
Meiosis45
Prophase I - chromatin condenses, nucleoli
disappear, sister chromatids are visible, spindle begins to form as centrosomes move away from one another. Homologous chromosomes synapse(come together) to form a tetrad (XX) andcrossing over(fragments of homologous chromosomes switch places - so the homologue that originated in an individual's mother now has portions of the father's chomosome attached, and vice versa!)
Meiosis46
Metaphase I - chromosomes line up, AS TETRADS
(homologous chromosomes line up as PAIRS rather than in single file as occurred in mitosis), on the metaphase plate (an imaginary line in the middle of the cell)
Meiosis47
Anaphase I - homologous chromosomes pull apart
but sister chromatids remain attached, one homologous chromosome moves towards one side ("pole") of the cell, while the other homologue moves towards the other side. Microtubules attached to the kinetochores of each chromosome shorten, thereby pulling the chromosomes poleward. Microtubules that are NOT attached to kinetochores lengthen, thereby elongating the cell.
Meiosis48
Telophase I - daughter nuclei begin to form. Note
that now, the two daughter cells have HALF the number of chromosomes as the original parent cell!!
Meiosis49
Prophase II - chromatin condenses, nucleoli
disappear, sister chromatids are visible, spindle begins to form as centrosomes move away from one another.
Meiosis50
Metaphase II - chromosomes line up, single file, on
the metaphase plate (an imaginary line in the middle of the cell)
Meiosis51
Anaphase II - sister chromatids uncouple and pull
apart, one sister chromatid (now called a full-fledged "chromosome"!) moves towards one side ("pole") of the cell, while the other sister chromatid moves towards the other side. Microtubules attached to the kinetochores of each chromosome shorten, thereby pulling the chromosomes poleward. Microtubules that are NOT attached to kinetochores lengthen, thereby elongating the cell.
Meiosis52
Telophase II - daughter nuclei begin to form, DNA
begins to "de-condense".
Comparison53
54