Warm-Up 3/28

1. Stimulus is a cause of physical response:something that causes a physical response in an organism, e.g. a drug or an electrical impulse
2. Medulla oblongata is a portion of the hindbrain that controls autonomic functionssuch as breathing, digestion and heart rate. Hypothalamus is a part of the brain does the job of connecting the endocrine system with the nervous system through the pituitary gland.
3.  Mechanoreceptors are receptor cells that detect sound 
4. 
5. Processing visual stimuli: Edge enhancement is a ‘pre- central nervous system ‘processing of information on the retina itself. This processing is not carried out by part of the brain but by the organisation of the retinal cells.

Contralateral processing is the way in which the brain collects and integrates information from the eyes to create the perception of seeing. Both these processes require a more detailed knowledge of the retina and brain. It should also be noted that this biology is still the subject of much research and the ideas presented are hypothetical.

Warm-Up 3/2

1. Steps in oogenesis:

Oogenesis is the process by which oogonia (primitive female egg cell developed during fetal development) becomes a zygote (the result of the mating of sperm and egg). During the first phase, the oogonia start meiosis but are stopped at prophase meiosis I during fetal development. During the second phase, increasing levels of FSH (follicle stimulating hormone) during puberty cause the primary follicular cells to grow and start producing estrogen. In the third phase, the secondary oocyte begins meiosis II and stops in metaphase. A secondary oocyte is ovulated. If the oocyte is fertilized, meisosis II resumes. The oocyte splits into an ovum and a second polar body. The sperm and ovum unite and form a diploid zygote.

2. Steps of spermatogenesis:

Spermatogenesis is the process whereby the seminiferous tubules produce sperm. There are three steps in spermatogenesis: 1) meiosis, during which the number of chromosomes in the cell is reduced to half or 23 chromosomes each; 2) meiosis II, during which each haploid cell forms spermatids; and 3) spermiogenesis, during which each spermatid develops into a sperm cell with a head and tail. The entire process of spermatogenesis takes about 64 days.

3. 

Spermatogenesis	Oogenesis
Number of gametes
Principle: continuous production. Although from puberty to old age sperm cells are constantly being engendered, the production is subject to extreme fluctuations regarding both quantity and quality.	Principle: Using up the oocytes generated before birth. Continual decrease of the oocytes, beginning with the fetal period. Exhaustion of the supply at menopause.
Meiotic output
Four functioning, small (head 4 mm), motile spermatozoids at the end of the meiosis	One large, immotile oocyte (diameter 120 mm) and three shriveled polar bodies are left at the end of the meiosis
Fetal period
No meiotic divisions	Entering into meiosis (arrested in the dictyotene stage)
No germ cell production	Production of the entire supply of germ cells

Warm-Up 2/27

1. fibrin

2. high pressure in afferent arterioles; leads to ultrafiltration in the glomerulus/through fenestrated capillaries in the glomerulus; drains through the Bowman’s capsule to the proximal convoluted tubule;

3. Water and solutes from filtrate within the nephron. The lining of the PCT contains many protein channels, which use both active and passive transport to move substances such as glucose and electrolytes across the tubule's lining and into the interstitial fluid for reabsorption

4. Benefits of vaccination

• Some diseases, such as small pox, can be eradicated.
• Deaths can be prevented, ex. from measles.
• Long-term disabilities can be prevented

• Rubella in pregnant women can lead to birth defects
• Mumps can cause infertility in men.

• Dangers of vaccination

• Immunity developed after vaccination may not be as effective as immunity developed in response to the actual disease.
• Dangers of side effects of some vaccines include:

• Whooping cough, vaccine can cause brain damage.
• Pregnant women, cancer patients, and others can be harmed by cross-infection from people vaccinated with the live virus, ex. smallpox vaccine.

Warm-Up 2/21

2. Explain antibody production

• An antigen is a foreign body in the blood. Examples of antigens include foreign proteins, pathogenic bacteria, and viruses.
• An antibody is a globular protein that recognizes an antigen and attaches to its surface, forming an antibody-antigen complex.

• When an antigen is in the blood, a lymphocyte with the correct antibody will attach to it and then respond by dividing to form a clone. The clone produces thousands of antibodies and secretes them to fight against the antigen.

• Phagocytes depend on antibodies to recognize antigens. When a phagocyte detects an antibody-antigen complex it ingests the whole complex by the process of phagoctytosis.

3.  Describe the production of monoclonal antibodies and their use in diagnosis and treatment

• Monoclonal antibodies are monospecific antibodies that are the same because they are made by identical immune cells that are all clones of a unique parent cell, in contrast to polyclonal antibodies which are made from several different immune cells. Monoclonal antibodies have monovalent affinity, in that they bind to the same epitope.

Warm-Up 2/17

1. Describe the steps of blood clotting

• A blood clot functions to seal a wound injured, preventing further invasions by bacteria.

• Clotting begins when the wall of a blood vessel is damaged. There are many different clotting factors involved including; platelets, prothrombin, and fibrinogen.

• Platelets are produced in the bone marrow at a rate of 200 billion a day; the bloodstream carries more than a trillion.

• Fibrinogen and prothrombin are proteins manufactured and deposited in blood by the liver.

• Vitamin K is necessary for the production of prothrombin.

• When a blood vessel is damaged, platelets clump at the site of the puncture and partially seal the leak.

• The platelets and the damaged tissues release a clotting factor called thrombokinase, which converts prothrombin to thrombin. This reaction requires calcium ions.

• Thrombin, in turn, acts as an enzyme that severs 2 short amino acid chains from each fibrinogen molecule. These activated fragments then join end to end, forming long threads of fibrin, which is insoluble.

• Fibrin threads wind around the platelet plug in the damaged area of the blood vessel and red blood cells get trapped within the fibrin threads, making the clot appear red.

2. Outline the immune response to an antigen

An antibody response is the culmination of a series of interactions between macrophages, T lymphocytes and B lymphocytes. Antigens are engulfed by antigen presenting cells (APC i.e. macrophages, Langerhans cells, dendritic cells, lymph nodes and monocytes), then they are partially degraded. Fragments of the antigen will appear on the surface of the APC attached to a cell surface glycoprotein known as MHC II (major histocompatibility complex). There are two types of MHC molecules: MHC class I which are expressed on the surfaces of most cells and class II which are expressed exclusively on the surfaces of antigen presenting cells. This antigen-MHC II complex allows helper T cells to bind to the APC which leads to a proliferation of helper T cells. The T cells then bind to the MHC complex on B cells which leads to proliferation and differentiation of the B cells. The B cells change into plasma cells which secrete large quantities of finely tuned antibodies. Some B cells are changed into memory cells which are primed for future challenges.

3. Discuss Active v Passive Immunity

These are two categories of immunity that exist. There are really only these two. 
Active immunity is immunity that occurs when YOUR BODY makes the antibodies. That is, if you get strep throat, your body makes antibodies for streptococcus whatever. You will be resistant to this bacteria for years, maybe you'll never get sick from it again. The same goes for illnesses like chicken pox, the flu, and many colds. 
Active immunity is also attained by receiving a vaccine. A dead or attenuated virus is injected in your bloodstream and you make antibodies. 

Passive immunity is attained 2 ways. First, is that when you're born, you receive antibodies from your mother, actually most frequently from breast milk. Another way is to receive an antibody serum, called an "antidote" in movies...this treatment exists, but is rare and impractical. 

Active immunity lasts for years and years. Sometimes an entire lifetime. Other times, you do need booster shots. Passive immunity lasts for a few months at best, as your body is not continuously making these. 

Passive immunity can help in an emergency, but such emergencies are rare. Active immunity, if you have the time to allow antibodies to be built up (weeks to months after your first shot), then this is the best method. 

Definitions 2/4

1. Homozygous - having two identical genes: having two identical genes at the corresponding loci of homologous chromosomes
2. Phenotype - physical traits
3. Carrier - Carries sex-linked disease but is not affected
4. Yes, both parents would have to be heterozygous
5.. Yes, because hemophilia is carried on the X trait

Warm-Up 1/13

1. what is the importance of standard deviation in regards to the mean?
The mean value tells us where the center is. The standard deviation gives us a clue about how broad or narrow the bell curve is. These two tell us about the field of values, and help us to know how the measurements for a whole population are distributed. 

2. What do error bars include?
they include about 2/3 of sample

3. What percentage of values fall within 1 standard deviation of the mean? and 2?
68%; 95%