Practical No (1) The Microscope
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2) Platyhelminthes Flat worms; Incomplete or absent digestive tract; No body cavity; Mostly hermaphroditic.
Tapeworms; Segmented bodies each segment containing complete set of male and female reproductive organs; No alimentary tract, nutrition by absorption through body wall e.g. Taenia (tapeworm).
Flukes; Leaf shaped Unsegment body, Complex life cycle e.g. - Clonorchis (liver fluke).
Multicellular, Male female septet, Always ectoparasite, Digestive system complete e.g. – Bed bugs, Mites, Ticks.
Draw all the organisms and label any organelles you were able to see on your sketches
Practical No (5) The Cell Division Mitosis:- All large organisms are composed of many cells. Growth of many-celled organisms involves an increase in the number of cells followed by an increase in size of the new cells. This is the basic mechanism by which a body grows and wounds are repaired. Cell division involves two major events: the distribution of identical copies of the genetic information from the parent cell to two daughter cells followed by cytoplasmic division. As a result of cell division, all the cells of a multicellular organism have the same genetic information. The parent cell divides by mitosis, producing two daughter cells. These two identical daughter cells contain exactly the same genetic material as the parent cell. Mitosis assures the production of identical sets of genetic information in the daughter cells. Mitosis is an orderly series of events that results in the equal distribution of the chromosomes that carry the genetic information to the two new cells. The process flows from one stage to the next without interruption. Traditionally, mitosis has been artificially divided into phases: prophase, metaphase, anaphase, and telophase. During this lab exercise, you will 1. Locate the interphase stage preceding mitosis in a plant cell and an animal cell. 2. Locate each of the following stages in a plant cell: a. Prophase
b. Metaphase c. Anaphase d. Telophase Exercise No (3) 1- Prepare the root tip squash Objectives 1. Prepare root tip squashes to observe mitosis in bean roots Vicia faba. 2. Identify the various stages of mitosis in Vicia faba root tips.
Bean roots, 1 mol HCl, basic fuchsin, Water, Petri dishes, forceps, slides & coverslips and microscope.
You will be provided with root that have been previously harvested and treated with a fixative to stabilize the cells. You will work in groups of two for this lab exercise. 1. Using scissors, cut 2 roots tips about 1 cm long, and transfer them into a petri dishes containing 1 M HCl. Left it for about 3- 4 minutes. *** Caution: Work with the HCl carefully, it is a strong acid. *** 2. Using forceps, carefully transfer the root tips to a small petri plate containing water. 3. Rinse the root tips 3 times with water from the dropper bottle, disposing of the rinses in the discard flask. 4. After removing the water from the third rinse, cover the root with the basic fuchsin stain. Left for about 5 minutes. 5. Transfer a root to the center of a clean microscope slide. 6. Cover the root tip with a cover slip, and then carefully push down on the cover slide with the wooden end of a dissecting probe. Push hard, but do not twist or push the cover slide sideways. The root tip should spread out to a diameter about 0.5 – 1 cm. 7. Scan the microscope under the objective lenses. Look for the region that has large nuclei relative to the size of the cell; among these cells will be found cells displaying stages of mitosis.
2- Draw and label a different stage of mitosis on your science book.
Practical No (6) The cell Division Meiosis:- Meiosis is a kind of cell division in which the cells produced (gametes) have half the number of chromosomes typical for the species. Meiosis occurs only in the gonads (testes and ovaries) of sexually reproducing organisms. The process of meiosis involves two divisions, with the first division (meiosis I) immediately followed by the second (meiosis II). During the first division of meiosis (meiosis I), the chromosomes join in homologous pairs. Homologous chromosomes are the same length and carry genetic information for the same characteristics. One chromosome of each pair originates from each of the parents of the individual in which meiosis is occurring. The pairing of homologous chromosomes is known as synapsis. Following synapsis, the pairs of homologous chromosomes line up at the equator of the cell. They then separate, and one member of each pair moves to each pole of the cell. When the two nuclei reorganize and cytokinesis occurs, the resultant two cells have one-half as many chromosomes as the original cell. Reduction from the diploid number (2n) of chromosomes to the haploid number (n) of chromosomes has been accomplished. Each of the two cells produced as a result of meiosis I goes through a second division. This second division (meiosis II) results in the formation of four cells. During this division, individual chromosomes line up on the equators of the cells. The centromeres divide and one of each of the chromatids (daughter chromosomes) moves to each pole of the cell. In males, the four cells that result from these meiotic divisions mature into sperm cells. Each cell has the haploid number of chromosomes, and each daughter chromosome (chromatid) is a single structure that carries a single DNA molecule. Each cell contains a complete set of genetic information for all the characteristics of an organism but the combination of characteristics in each gamete is different from that in others. In females, only one of the four cells matures into an egg. The other three cells die. However, the same processes that generate variety in the kinds of sperm produced also are involved in producing eggs so that eggs are as different from one another as are sperm.
1 - Draw the stage of meiosis from the Pic. 2- Write the different between mitosis and meiosis.
Practical No (7) Epithelial Tissue The four basic tissue types in the body are the epithelial, connective, muscular, and nervous tissue. These tissues exist and function in close association with one another. The epithelial tissue, or epithelium, consists of sheets of cells that cover the
and glands, and line their ducts. Epithelial cells are in contact with each other, either in a single layer or in multiple layers. The structure of lining epithelium, however, differs from organ to organ, depending on its location and function. For example, epithelium that covers the outer surfaces of the body and serves as a protective layer differs from the epithelium that lines the internal organs. The overview illustration shows different types of epithelia in selected organs. - The Epithelium is classified according to the number of cell layers and the morphology or structure of the surface cells. A basement membrane is a thin, non-cellular region that separates the epithelium from the underlying connective tissue. This membrane is easily seen with a light microscope.
- Simple squamous epithelium:- 1- The cells of the simple squamous epithelium appear flat and nucleus is oval shape.
2- Covers the external surfaces of the digestive organs, lungs, and heart are called mesothelium. 3- Simple squamous epithelium that covers the Lumina of the heart chambers, blood vessels, and lymphatic vessels is called endothelium. - Simple cuboidal epithelium:-
kidney.
- Simple columnar epithelium:- 1- It is the tall cell. 2- The nucleus is oval shape and located near of the basement membrane. 3- Covers the digestive organs (stomach, small and large intestines, and gallbladder). In the small intestine, simple columnar absorptive cells that cover the absorptive cells that cover the Villi.
- Which is simple epithelium with two types of cell resting on the same basement membrane but are not all reaches the surface ( short basal cells with spherical nuclei located near the basement membrane and tall columnar cells with oval nuclei located near surface ). - Pseudo stratified columnar epithelium lines the respiratory passages and Lumina of the epididymis and vas deferens.
and larger bronchioles. 3- Stratified Epithelium:- - Stratified squamous epithelium:- 1- Contains multiple cell layers. 2- The basal cells are cuboidal to columnar; these cells give rise to cells that migrate toward the surface and become squamous. 3- There are two types of stratified squamous epithelia: non-keratinized (cover the cavities of mouth, pharynx, esophagus, vagina, and anal canal) and keratinized (lines the external surfaces of the body). - Transitional epithelium:- 1- This type of epithelium changes shape and can resemble either stratified squamous or stratified cuboidal epithelia. 2- Transitional epithelium is contracted, the surface cells appear dome- shaped; when stretched, and the epithelium appears squamous. 3- This tissue found in pelvis, ureter, and bladder of the urinary system. Glandular Tissue A special type of epithelium tissue that is specialized for secretion. Exocrine Glands:- • Can be unicellular or multicellular. • Multicellular glands contain secretory portion and ductal portion. • Secretions enter the ductal system. • Simple tubular glands exhibit unbranched duct; found in intestinal glands. • Coiled tubular glands seen in sweat glands. • Compound glands exhibit repeated ductal branching with either acinar (alveolar) or tubular secretory portions. • Merocrine glands, like pancreas, release secretion without cell loss. • Holocrine glands, like sebaceous skin glands, release secretion with cell components.
They: • Are individual cells as enteroendocrine cells in digestive organs. • Are endocrine portions in organs such as pancreatic islets in pancreas. • Are endocrine glands such as pituitary, thyroid, or adrenal glands. • Do not have ducts. • Are highly vascularized. • Secretory products enter bloodstream (capillaries) for systemic distribution.
1- Examine a section of the kidney, using magnification of 400X for simple squamous epithelium. Note: Draw the simple squamous from the microscope in the box and label the nucleus and cytoplasm. 2- Examine a section of the kidney (collecting ducts), stain with H&E stain for a simple cuboidal epithelium using magnification of 400X. Note: Draw a section from the microscope in the box and label the nucleus and cytoplasm.
simple columnar epithelium using magnification of 400X. Note: Draw a section from the microscope in the box, label the nucleus and goblet cell. 4- Examine a section of the trachea, for a Pseudostratified columnar ciliated epithelium using magnification of 400X. Note: Draw the section from the microscope in the box and label the nucleus and cilia. 5- Examine a section of the distended urinary bladder or ureter, for a transitional epithelium using magnification of 400X Note: Draw the section from the microscope and label the nucleus.
keratinized epithelium using magnification of 400X Note: Draw the layer of section from the microscope and label the keratin layer.
7- Examine a section of the esophagus, for a stratified squamous non keratinized epithelium using magnification of 400X Note: Draw the layer of section from the microscope. 8- Examine a section of the pancreas gland (Endocrine and Exocrinestain for a transitional epithelium using magnification of 400X. Note: Draw the section and label endocrine and exocrine.
Practical No (8) Connective Tissue The connective tissue binds and supports other tissue. Connective tissue consists of cells and extracellular material called matrix. The extracellular matrix consists of connective tissue fluid, ground substance within which are embedded the different protein fibers (collagen, reticular, and elastic). The connective tissue is classified as either loose connective tissue or dense connective tissue, depending on the amount, type, arrangement, and abundance of cells, fibers, and ground substance. The connective tissue fibers are classified histological into three types: 1- Collagen Fibers:- - They are also termed White fibers. - They are present in the form of either Regular or Irregular bundles. - The fibers are thick. - Found in the most organs such as skin.
- They are also named Yellow Fibers. - The fibers is single and has a wavy shape with small branches. - It is present in organs that need some sort of elasticity like the aorta. 3- Reticular Fibers:- - They are short branching fibers that form a network. - It is found in liver and Lymph nodes.
cell forming the adipose tissue which is present in different positions in the body such as around the heart and kidney.
The connective tissue divided according of the matrix into three types:- 1- Cartilage (With semisolid matrix). The cartilage consists of cell chondrocytes and matrix which contain the collagen or elastic fibers. The main function of supporting soft tissues. They are three types of cartilage: a- Hyaline Cartilage:- - The matrix is homogeneous and slightly. - The cell it is called chondrocytes located inside the lacunae. - The type of fiber present is collagen although it is indistinguishable. - They are surrounded by C.T capsule that known as perichondrium. - E.g. Trachea. b- Elastic Cartilage:- - The matrix it is contain the elastic fibers. - The cell is chondrocytes located inside the lacunae. - They are surrounded by C.T capsule that known as perichondrium. - E.g. External ear and epiglottis. c- Fibro Cartilage:- - The matrix it is contain the bundles of collagen fibers. - The chondrocytes it is smaller. - The perichondrium is lacks and found in the intervertebral discs. 2- Bones (With a solid matrix). The bones is gives the skeleton of the body. It is consist of different types of cell osteocytes and osteoblast. They are contains two types of bone compact bone and spongy bone. Compact Bones:- - The types of cell it is called osteocytes located in lacunae. - The structural units are known as Haversion systems, which are consist of concentrically arranged lamellae around the central or haversion canal. - Found in the long bones (arms and legs). 3- Blood (With fluid matrix):- The blood it is contains cells (Erythrocyte- Leukocyte- Thrombocyte) and fluid matrix (plasma).
presence or absence of granules in cytoplasm: A- Granulated: 1- Acidophil: It is bilobed nucleus and red granules (acidophilic). 2- Basophil: It is bilobed nucleus and blue granules. 3- Neutrophil: It is 3-4 lobes nucleus and the granules are invisible because they do not take a stain. B- A granulated: - Lymphocyte: It has a large round nucleus. - Monocyte: It has a large kidney shape nucleus. Exercise No (8) 1- Examine a section of collagen fibers in tendons using magnification of 400X
Note: Draw the section from the microscope in the box and label the fibroblast. 2- Examine a section of the reticular fibers in liver using magnification of 400X.
Note: Draw the section from the microscope in the box and label the fibers. 3- Examine a section of the elastic fibers in aorta using magnification of 400X.
Note: Draw the section from the microscope in the box and label the fibers. 4- Examine a section of the adipose tissue in kidney using magnification of 400X.
Note: Draw the section from the microscope in the box and label the nucleus of adipose cells. 5- Examine a section of the hyaline cartilage in trachea using magnification 400X.
Note: Draw the section from the microscope and label the chondrocytes, lacunae, matrix and perichondrium. 6- Examine a section of the elastic cartilage in epiglottis using magnification 400X.
Note: Draw the section from the microscope in the box and label the chondrocytes, lacunae, matrix and perichondrium. 7- Examine a section of the Fibro cartilage in intervertebral disk using magnification 400X. Note: Draw the section from the microscope in the box and label the chondrocytes, lacunae, matrix and fibers. 8- Examine a section of the compact bone by the 100X and 400X. Note: Draw the section from the microscope in the box; label the osteocytes and haversion system (central canal).
Note: Draw the different blood cell from the microscope in the box and label the nucleus.
Practical No (9) Muscle Tissue There are three types of muscle tissues in the body: skeletal muscle, cardiac muscle, and smooth muscle. Each muscle type has structural and functional similarities, as well as differences. All muscle tissues consist of elongated cells called fibers. The cytoplasm of muscle cells is called
which contain two types of contractile protein filaments, actin and myosin. The types of muscle:- Skeletal Muscle:- 1- The muscle fibers are long, cylindrical, multinucleated cells, with peripheral nuclei. 2- The arrangement of actin and myosin filaments is very regular. Yüklə 0,55 Mb. Dostları ilə paylaş:
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