Biology Lab Assignment Paper: Carrying Out Lab Tests (Coursework Sample)

Questions and Answers – use this document to record your answers. You will enter your responses in the Lab Report.
1 What are the defining physical characteristics of each of the four major tissue types? In other words, if you were to look at a general image of each tissue type, how could you tell which is which?
Animal tissues include four basic types these are: epithelium ,connective, muscular and nervous
* Epithelium
Epithelial tissues provide a lining to all the external surfaces and internal cavities of an animal's body
Epithelium may be distinguished by their morphological appearance, which in turn is dependent on the location of the tissue and the particular tasks it must accomplish.
Epithelial tissues has a basement membrane, a non-cellular, fibrous layer of material that separates the epithelium from the underlying tissues
* Connective
Connective tissues consist of one or more cell types embedded in a matrix.
The matrix consists of widely dispersed fibers embedded in a ground substance
A number of forms of connective tissues exist depending on the relative types, quantities, and arrangements of the three components cells, fibers, and ground substance
* Muscular
The muscle cells are wrapped by fibro connective tissue which maintains the shape of the muscle, and carries the blood vessels and nerves to the muscle tissue.
The muscle cells are elongate, and are often referred to as muscle fibers. These contain the intracellular contractile elements, the filaments.
* Nervous
The nervous tissue has a basic unit which is the neuron
Nervous tissue carries a fundamental property of living tissue, irritability, to an extreme degree, being highly specialized to receive and transmit internal as well as external stimuli.
2.What are the physical differences among the types of epithelial tissues you studied? (Hint: this does not include the subtypes as well).
The physical differences among different types of epithelial tissues,
They include
* Simple squamous epithelium
This type of epithelium is found covering surfaces that are not exposed too much irritation.
Simple squamous epithelium has fluid-filled body cavities are also lined with called mesothelium.
Simple squamous epithelium has a nucleus
* Simple cuboidal epithelium
Simple cuboidal epithelium cells withstand more traumas
Simple cuboidal epithelium is adapted for diffusion and secretion
Simple cuboidal epithelium is found in organs that are specialized for secretion, such as salivary glands
Simple cuboidal epithelium tissue consists of a single layer of cuboidal cells on the basement membrane.
Simple cuboidal epithelial tissue lines the tubules
* Simple columnar epithelium
Simple columnar epithelium cells are specialized for absorption, and are commonly found in areas where there is considerable wear and tear, such as the digestive tract.
Simple columnar epithelium has mucous-secreting goblet cells
Simple columnar epithelial cells has microvillus
* Pseudo stratified columnar epithelium
Pseudo stratified columnar epithelium is found lining the trachea, bronchi, male urethra
Ciliation is another specialization of pseudo stratified columnar epithelium
* Stratified squamous epithelium
Stratified epithelium provides protection for underlying tissues.
Stratified epithelia are normally found in places where there is a great deal of wear and tear.
The outer surface of these epithelia is sloughed off and replaced by cells below it. Thus, the deeper layers of such epithelia are mitotic ally active.
One of the most common types of stratified epithelium is stratified squamous.
3.What are the physical differences among the types of connective tissues?
* Loose connective tissue
This form of connective tissue consists of a number of cell types embedded in a matrix characterized by a large amount of ground substance in which fibers are arranged in a loose irregular manner.
Loose connective tissue is found in all parts of the body and is responsible for binding various structures together, such as muscle fibers to muscle fibers, and skin to underlying tissues.
Various membranes and mesenteries are also composed of loose connective tissue.
The most common cell type is the fibroblast. These cells are responsible for production of the extra-cellular fibers and matrix.
* Dense connective tissue
It has tendons, which attach muscles to bones, and ligaments, which connect bones to bones
In tendons, the matrix consists largely of collagen fibers, which are flexible and resist stretching. Ligaments contain a high proportion of elastic fibers, which allow more stretch.
* Adipose tissue
It has cytoplasm and nucleus pushed to the side by the presence of a large vacuole in the center of each cell. This vacuole is the site of fat storage.
* Cartilage
Cartilage is a form of connective tissue that is incorporated to varying degrees in the skeletons of vertebrates
The texture of cartilage has been described as "rubbery
4.What are the three types of muscular tissue? Can you describe the physical differences among them?
The three types of muscle found in vertebrates are:
(1) Smooth
(2) Skeletal
(3) Cardiac
* Skeletal muscle
Skeletal muscle is striated that is it has stripes and is under the control of the somatic nervous system.
Skeletal muscle is responsible for the movement of the skeletal system.
Skeletal muscle cells are very large, and are actually a fusion of a number of cells
These cells have my filaments which are arranged in a regular pattern, producing the striated appearance.
The nuclei in skeletal muscle are found at the periphery of the cells
* Cardiac muscle
It is striated and under the control of the autonomic nervous system. 
Cardiac muscle is comprised of uninucleate branching cells connected together by intercalated discs). 
Each cell has a single nucleus.  
* Smooth muscle
Smooth muscle is composed of uninucleate, unbranched cells which are under the control of the autonomic nervous system
Because the contractile my filaments are not highly organized, no banding pattern is apparent.
Relaxed smooth muscle cells are slender and elongate, with a centrally placed nucleus.
Smooth muscle is usually arranged in two layers around the hollow tubes of the body: circular and longitudinal.
5.Can you identify the parts of neurons described in this lab and explain their function?
The parts of neurons consist of
a) A nerve cell body which performs several processes
b) Dendrites, which carry impulses toward the nerve cell body,
c)Axons, which carry impulses away from the cell body.
6.Where are each of the tissue types and subtypes found, and what are their functions? There should be a lot of information in this answer
* Epithelial tissues
Are found on both external and internal organs because they provide lining to all the external surface
(1) Protection of the underlying tissues,
(2) Absorption,
(3) Secretion,
(4) Reception of sensory stimuli. faces and internal cavities of an animal's body
Subtypes
* Keratinized stratified squ...