Cell biology lab histology/tissues Study Guide
    The goal of this series of labs is to visualize the very broad diversity of cell types found in nature.  Emphasize the biochemical nature of the structures-- lipid membranes, carbohydrate cell walls, etc.  Note that cells specialize for different environments/functions-- emphasize that they become specialized by making different proteins and enzymes.  These labs also emphasize the ability to properly use and manipulate a microscope-- it's not all that easy to visualize things well!  Students will not only need to be able to identify particular cells and tissues, but also answer questions about them.  For their notebooks, they should have drawings (with labels!) of what they see (dock points for lack of effort and labels, not artistic ability!).  Comment also on how different sections were prepared-- stains can be very different (as seen previously).

Protozoans/Fungi

Amoebas: engulf their prey; move around by directed movement of their cytoplasm; very irregular shapes; attach to some surface.  Irregular shaped pink bodies.

Paramecium: ovoid unicellular organism with lots of cilia (made of tubulin, like flagella); relatively large NOTE: the pink leggy critters are NOT paramecium-- seem to be found in many of the slides!  big irregular shaped pink blob is the macronucleus- pink nearby is micronucleus

chlamydomonas: mobile prokaryotic algae with 2 flagella coming out from behind it; 2 sexes that appear the same  2 flagella are hard to see with these microscopes unfortunately, so look round/oval

volvox: colony organism; photosynthetic (green color); 2 cell types-- somatic cells that are structurally similar to chlamydomonas + germ cells that are the large green circles in the middle
after sexual fertilization, volvox develops in the body-- baby volvox grow inside until it bursts!

oscillatoria: long colony organism; prokaryote; blue-green algae; striations mark cell bodies!

rhizopus sporangia: filamentous fungi with spore asci-- some filaments are branched and irregular (anchor the mold) others are straighter-- expand the colony; common allergen!

Plant Tissues

Angiosperm leaves: look at the different types of cells present in the leaves (guard cells, mesophyll cells, etc. identify chloroplasts at high power with oil immersion; note cell walls; note large vaculoles in some cells but not as visible in others

Mature stem: phloem, xylem, various supporting cells etc.  compare chloroplasts in leaves vs stems; compare cell walls and vacuoles Note the relative lack of spongy tissue

Allium root tip: note lack of chloroplasts!  Look for mitotic chromosomes in dividing cells; examine mitotic chromosomes using oil immersion!  Do you see chromosomes in leafs or stems?  most are not dividing! How many chloroplasts are there? compare cell walls and vacuoles

Sphagnum (moss) Antheridia:  plant male germ cells; how are mosses different from angiosperms

lillium stigma and pollen tubes: method of plant fertilization; identify stigma and pollen tube structures (oil immersion); look for chloroplasts; cell walls, and vaculoles; find pollen grains at the top, follow the pollen tubes down

Animal Tissues

Drosophila chromosome squash: flies have extremely LARGE chromosomes in their salivary glands;  the long twisted strands in this preparation are polytene chromosomes.  Note the stained bands-- this is how early geneticists first located genes on DNA!

Golgi Stained Cerebellum: staining technique that labels semi-random cells a dark brown/black and allows their morphology to be studied.  Look for cell bodies as well as processes.  Find the extensively branched filaments (dendrites) as opposed to the thicker/longer/straighter axons

Motor nerve endings: how nerve cells stimulate muscles; note the flattened end plates; do end plates cluster together? see drawing  How many end plates do you find on separate muscle fibers?  Nerves enter in a bundle (fascicle) and then branch out to innervate individual fibers

Skeletal Muscle: note the parallel tight arrangement of muscle fibers; examine under oil immersion to identify actin fibers of the cytoskeleton; myosin (in horizontal lines) moves the actin fibers to contract the muscles; could plant cells do this?  Why? Note the multiple muscle nuclei- are they in the middle of the cells or towards the edges of the muscle fibers (edges)

Cardiac Muscle: striated like skeletal muscle, but NOT multinucleated; only found in heart; nuclei are centrally located!

Smooth Muscle:  involuntary; not striated; found in many internal organs (ie. trachea, small intestine)

Blood: identify the red blood cells (erythrocytes also see platelets); note some species can be nucleated, others not- look at both kinds; comment on shape of human red blood cells-- why flattened discs? (increased surface area)- compare to sickle cell blood; Note the nucleated white blood cells-- immune system function (foreign cells, viruses, etc) why would they need nuclei? (need to respond and make new proteins to fight a threat-- red blood cells only have to carry oxygen) note different types of white blood cells- B/T cells, eosinophils, basophils, neutrophils

Bone: very large dense extracellular matrix; try to find concentric circles around the haversian canals with layers (lamellae) and lacuni (small openings where osteocytes are) with radiating canniculi; look at the bone structure using oil immersion and note the irregular branched morphology of the osteocytes

Tendon: another type of extracellular matrix (are attachment sites visible?); where are the cells ( visible as very elongated cell bodies-- look for nuclei)

Kidney: point out the epithelial cells lining the kidney tubules; what do they do? (provide a barrier for liquid in the tubules); note the glomeruli- clusters of non-epithelial cells; papillary ducts and collecting tubules; note cuboidal vs. columnar epithelial cells in tubules

Trachea: note the ciliated epithelia lining the trachea-- on one side of the epithelia only; what do they do? (clear foreign particles away from the lungs); note the supporting cells layering around the trachea-- cartilage, smooth muscle, large gaps!, etc  compare to kidney and skin

Testes:  ductus epididymis/differens(thicker muscle layer); smooth muscle fibers around ducts; mucosal folds; ciliated pseudostratified columnar epithelia lining ducts

Small intestine:  brush border cells- release mucus; ciliated columnar epithelial cells lining the microvilli; blood vessels to collect nutrients; smooth muscles to force food along- peristalsis; gut associated lymphoid tissue for localized immune response

Vertical Skin Section:  identify major cell types (keratinized epithelia, epithelial cells, dermal cells, blood vessels, adipose tissue, follicles, glands etc); why are the keratinized epithelia found on the outside? (dead cells easier/safer to lose on the outside-- living cells on the inside; additional protection); note again the distinction between less packed mesodermal cells vs. epithelial cells