Human blood, at 0.
A slice across a stem, at right angles to the axis of the stem, is a transverse section, T. Any slice parallel to the axis of a stem is a longitudinal section, L. A slice vertically down is a vertical section, V.
A slice parallel to the axis of the stem, along the radius, is a radial longitudinal section, R. A slice parallel to the axis of the stem, along a tangent to the cross-section, is a tangential longitudinal section, T. Cut a wedge-shaped transverse section across a soft stem, e.
Note the groups of similar cells, tissues. The epidermis is the one cell thick outer layer. It may have a waxy cuticle on the outside to protect against desiccation.
The bundles of cells, vascular bundles, contain food conducting phloem cells on the outside and water conducting xylem cells on the inside. The walls of the xylem cells, vessels, are strengthened. Old xylem forms wood. Groups of cells with very thick walls, sclerenchyma, strengthen the stem. Parenchyma tissue is the loose packing cells.
Between the xylem and the phloem are closely packed cells with large nuclei and thin walls, the cambium.
Cambium cells produce new cells by mitosis to make the stem thicker. Draw a map diagram to show the different tissues.
Observe the remaining stump of a cut down tree or the sawn end of a thick branch. Note the sap wood, heart wood, annual rings, phloem and bark. The appearance of the rays shows the type of section.
In transverse section, T.
In radial longitudinal section, R. Any broken appearance is caused by the section not being exactly radial. In tangential longitudinal section, T. Find the rays and identify the type of section.
Parenchyma cells of tomato 1. Look for the thin cell wall, plasma membrane, vacuole, cytoplasm, chromoplasts, and nucleus. Remove a very small portion of the pulpy tissue immediately beneath the skin of a tomato fruit.
Mount this on a slide in water and then tease it out with dissecting needles. Apply a coverslip and examine under high power. Note the parenchyma cells containing orange-red chromoplasts and cytoplasm, nucleus and vacuoles.
Stain with iodine solution and examine the structure in detail. Vascular bundle See diagram 9. Note the collenchyma, cortex, endodermis, pericycle, pith often brokenparenchyma packing tissuesphloem, xylem, cambium, bicollateral vascular bundle phloem both outside and inside xylemcharacteristic of pumpkins and melons.
Examine a transverse section and a longitudinal section. Note the general arrangement of the bicollateral bundles, with the phloem both internal and external to the xylem in the vascular bundles.
Sieve tubes form vertical files of cells placed end to end.The Effect of Water Concentration on the Mass of Potato Tissue Essay - The Effect of Water Concentration on the Mass of Potato Tissue Aim: The aim of this investigation is to discover the effect of water concentration on the mass of potato tissue, and also to investigate the movement of osmosis through potato tissue.
1. The cells of an onion skin are generally rectangular in shape and range in size from to millimeters in length ( micrometers).
BioCoach Activity Plant Structure and Growth Introduction.
This BioCoach activity can help you review the basic structure and growth of flowering plants (angiosperms). LabBench Activity Osmosis. Osmosis is a specialized case of diffusion that involves the passive transport of water.
In osmosis water moves through a selectively permeable membrane from a region of its higher concentration to a region of its lower concentration. The membrane selectively allows passage of certain types of molecules while restricting the movement of others.
Source: Bourdoux et al., Sweet potato.
Sweet potato contains raffinose, one of the sugars responsible for flatulence. Three of the sugars which occur in plant tissues, raffinose, stachyose and verbascose are not digested in the upper digestive tract, and so are fermented by colon bacteria to yield the flatus gases, hydrogen and carbon dioxide.
Beneath the description of each experiment you will find links from which you can open or download the experiments in Word format, and a link from which you can download the group of documents in a zip file.