1. List the 4 primary tissue types and give the general characteristics and functions of each one. Nerve Tissue: transmit nerve impulses; coordinates and regulates body activities, bind and support nerve tissue; carry on phagocytosis; connect neurons to blood vessels, changes shape from squamous to cuboidal Epithelial Tissue: covers all free body surfaces and lines organs, anchored to connective tissue by basement membrane, lacks blood vessels, can reproduce Connective Tissue: connects, supports, protects, provides framework, fills spaces, stores fat, and produces blood cells consists of cells, usually some distance apart, and intercellular material, scar tissue is a type of connective tissue, able to reproduce; original embryonic connective tissue is called mesenchyme Muscle tissue:moves parts attached to it; cell called a fiber; fibers change shape in order to move 2. How are epithelial tissues classified?
1. simple--consists of one layer of cells
2. stratified--two or more layers of cells
3. pseudo stratified--appears to be layered but it is not
3. How does the type of epithelial tissue relate to its function? Give at least 1 example of where you would find each type of epithelial tissue. The cells are tightly packed, which allows epithelial tissue to function to form linings or coverings EX: Thickness serves them well in the lung alveoli. The rate of diffusion is inversely dependent on the thickness of the surface through which diffusion occurs; the thicker the layers, the slower the diffusion. 4. Differentiate between exocrine and endocrine glands. Give an example of each. Exocrine: secrete their products into one or more ducts that open into the skin or mucous membranes. EXAMPLE: mammary glands- milk goes through the lactiferous duct for breast feeding. Endocrine: endocrine glands: don’t have ducts but secrete their products into the blood EXAMPLE: Pancreas releases insulin and glucagon directly to the blood stream, affecting almost immediately your metabolism.
5. What is the difference between apocrine, merocrine and holocrine glands? Which is the most common? Apocrine is part of the plasma membrane contains secretion, holocrine is a whole cell that breaks down to secrete its substance; merocrine is when a substance is secreted by exocytosis. Merocrine is the most common 6. Describe connective tissue’s intercellular material. matrix is formed of ground substances and fibers
There are 3 types of fibers which make up connective tissue
a. collagenous fibers, they are most abundant type; appears in bands; also known as white fibers b. elastic fibers, which are composed of elastin; pliable and elastic; also known as yellow fibers c. reticular fibers are highly branched; short, thin and delicate 7. What are the 8 main types of connective tissue? Briefly describe each. 1. loose connective tissue--most widely distributed; found beneath the skin and between muscles 2. adipose tissue--a specialized form of loose that stores fat; found beneath the skin and around the kidneys, heart, and various joints 3. fibrous connective tissue--composed of strong, collagenous fibers; found in tendons and ligaments 4. elastic connective tissue--composed of elastic fibers with fibroblasts; found in the walls of the arteries, bronchial tubes and vocal cords 5. cartilage- chondroitin is the major component; provides support and framework 6. bone- most rigid of the connective tissues, supports the body; protects vital parts; serves as a point of attachment for muscles; forms blood cells and stores various minerals 7. blood--composed of cells (red, white and platelets) suspended in a fluid (plasma); formed in the bone marrow 8. reticular connective tissue--composed of many phagocytic cells; protects body against invasion; found in lymph 8. Order the types of connective tissue from most rigid to softest. Be sure that you understand why? Bone is the most rigid, and then comes cartilage, dense connective tissue, loose connective tissue, softest, blood. 9. Describe the 3 types of cartilage? Which is the most abundant? Hyaline cartilage is found on many joint surfaces, it has a very firm consistency. It contains no nerves or blood vessels, and its structure is relatively simple. Elastic cartilage, also called yellow cartilage, is present in the ears; it contains elastic fiber networks and collagen fibers. Fibrocartilage is very tough tissue; found between the bony parts of the backbone and the knee 10. Differentiate between the 3 types of muscle tissue.
1. skeletal muscles--attached to bones; have striations; voluntary; multinucleic 2. smooth muscle--found in the wall of internal organs; no striations; involuntary; mononucleic 3. cardiac muscle--found in the heart; striated; involuntary; have a single nuclei; have intercalated discs that connect between cells 11. What are the basic steps of tissue repair?
1. Clotting proteins create a clot which stops the loss of blood, holds the edges of the wound together and prevents bacteria and other harmful substances from spreading to surrounding tissues 2. Clot dries and forms a scab
3. Granulation tissue forms next
4. epithelium grows back together covering the scar tissue
12. What is the composition of DNA?
a sugar, 4 bases and as phosphate unit
13. How are nucleotides paired in DNA? What is different with RNA? Adenine with thymine and cytosine with guanine. RNA has ribose sugars. DNA has adenine, thymine, guanine, and cytosine. A pairs with T and C with G. In RNA, Uracil replaces thymine. So instead of A and T, A pairs with U. 14. Explain the process of DNA replication and when it occurs. In DNA replication, the double helix unwinds, and one side of the helix, is used as a template to make the other strand. And when both strands are completed, they pair, and then there are two copies of DNA in the cell. This occurs only during mitosis, but more specifically, during interphase. 15. What specifies that amino acid sequence of a protein? Each sequence codes for a specific amino acid. Each sequence is called a codon, made up of three letters. The DNA is copied by the mRNA and then transferred on the ribosome with tRNA to make a codon and anti-codon, which will code for the amino acid. And then it is added to the DNA sequence that codes for the next acid.
16. What is RNA? How are the 3 types different in function? messenger RNA, Ribosomal RNA, Transfer RNA. mRNA carries information from DNA to the ribosome. The coding sequence of the RNA decides the codon. tRNA is a small chain of RNA that transfers a specific amino scid to a growing chain at the ribosome. rRNA is a component of the ribosomes, the protein synthetic factories in the cell. Eukaryotic ribosome contains four different rRNA molecules: 18 s, 5.8 s, 28 s, and 5 s rRNA. Three of the rRNA molecules are synthesized in the nucleolus, and one is synthesized elsewhere. rRNA molecules are extremely abundant. They make up at least 80% of the RNA molecules found in a typical eukaryotic cell. 17. How are triplet codes, codons, and amino acids related? Triplet codes are when three set of amino acid code for a particular character then called as triplet codon. Codons are sets of three nucleotides that code for a specific amino acid. Amino acids what are made from these codons, that’s how they’re all related, because the other two make up the amino acids. 18. What is the purpose of mitosis?
Function to create the reproduction and replacement of cells. Growth 19. Briefly describe what happens in each phase of mitosis? In interphase the cell grows, in three stages.G1 S1 and G2 S2. In prophase The nucleus goes away, and the chromosomes condense into chromatids. In metaphase the two centrosomes start pulling the chromosomes through their attached centromeres towards the two ends of the cell. In anaphase The proteins that bind sister chromatids together break apart, creating to separate daughter chromosomes. In Telophase The nucleoli reappear, too. Both sets of chromosomes, now surrounded by new nuclei, begin to "relax" or de condense back into chromatin. In cytokinesis In cytokinesis, the cytoplasm divides, and the amount of chromosomes is regulated so it remains at the constant number of 46. 20. What is the purpose of meiosis?
Meiosis produces the gametes or the "sex cells" such as sperm and eggs. Meiosis goes through two divisions, one in meiosis 1 and one in meiosis 2. In the end, it results in four cells and each cell only contains half of the genetic material. At fertilization, male and female gametes come together to form a new being with half of its mothers genes and half of its fathers. 21. Explain the relationship between gametes, zygote, blastocyst, embryo and fetus. This is a cycle of growth in the womb, the relationship is that they all go through these stages before they are birthed.