Mendel made his hypotheses without any knowledge of DNA whatsoever. His two laws he discovered each can be proven without DNA or a microscope or both. This shows how great of a scientist Mendel was. He probably understood that something took the form of a genetic material but did not know that DNA was it. He also uses fairly obvious observations to support his claims opposed to very specific observations one can make when looking at the DNA of a creature. He based his work off of characteristics, not genetic material. Although he is sometimes called the father of genetics, he
In this three class lesson, I learned that cell division happens in many different ways. One of these ways is meiosis, or the creation of sex cells in more complex organisms. Another is a very simple kind of replication, binary fission. This type of replication occurs in single celled prokaryotes. All cell division happens to further continue a particular species. Although there are many types of cell division, they each serve a specific function that they are effective at.
For organisms larger than one cell, another method of reproduction was required. Mitosis makes two cells from one. Meiosis works much faster, using one cell to create four. The usage of meiosis also allows for two parents to come together to combine DNA. This is an evolutionary advantage, as a single set of parents could pass advantages in their genes to more than two offspring. For sexual reproduction to happen, meiosis is needed to create the the sex cells. With larger and more complex organisms such as humans, reproduction requires haploids to carry the information from two separate organisms to coming and form a diploid zygote.
In this three class lesson, I learned that an action potential is when a neuron changes the charge of itself to positive from negative. It does this by using several sodium potassium pumps which allow positive ions to flow into the neuron. This changes all the way down the neuron, and continues onto the next one. A resting potential is when a neuron has a negative charge, and is waiting to change positive and carry on a signal. The action potential is carried over a synapse.
The video shows how complex neurons are and how a similar amount of pressure in a touch can set off different reactions. The video touches on a point where the central nervous system in your spinal cord is responsible for moving your body and creating quick reflexes. This happens because the neuron picks up danger, and you body instantly reacts to it without having to think about it. The video also talks about how a hair, for example, can be connected to a neuron which them can pick up a stimulus from the hair.
In this three class lesson, I learned the way that our body defends itself from invaders otherwise known as antigens. The body has external barriers, that keep unwanted germs out. Examples of these are the skin, nose hairs, and mucus. The body also has an immune response in which the body's cells consume or destroy the antigens. The most basic of this defense system are macrophages that eat up an antigen through a process called phagocytosis. The other main part of the response is the generation of antibodies. The B cells create antibodies specific to the type of antigen invading. The white blood cells carry the antibodies to the T cells, which in turn, destroy the antigens by either weighing them down with antibodies or tearing the antigens apart. The immune system is vital for keeping humans alive, as in a situation when a person does not have a fully functioning immune system such as the onset of AIDS, humans do not last long without medication.
The HIV virus destroys helper T cells. This allows the body to not be able to hold off invaders, as the immune system will have lost some of its major components. The reason that HIV is not the official cause of death in those who die with it inside their bodies is because the virus allows the body to be extremely vulnerable to other viruses and diseases. Without the immune system to help the body defend against invaders, a person can die from easy to contract illnesses such as a flu or other type of pathogen. In this way, the HIV virus does not directly kill a human being
In animals that are larger, the heart beats fewer times a minute. Heart rate equals .289 - .202 times the weight. This equation means that if an animals if larger in terms of weight, then it's heart will beat less than a smaller animal. An example of this is a hamptster, whose heart beats 450 times a minute and an elephant whose heart beats 30 times a minute. This equation has a lot to do with an animals expected lifespan because mammal hearts only can beat roughly between .6 and 2.2 billion times before it starts to deteriorate. Hearts no matter the size can only beat so many times just like machines that get worn out.In the lesson, I learned that there are different types of joints that connect bones. The three types of joints are ball and socket, hinge, and pivot joints. The ball and socket is the most mobile type as it can allow the appendage to rotate in all directions and gives the attaching joint the largest range of movement. The hinge joint and pivot joints allow for movement on one plane. An example of this is in the knee a hinge joint allows for forwards and backwards movement.
Because fast twitch muscles wear out much quicker, professional football players tend to be much younger than marathon runners. The marathoners make use of their slow twitch muscles, which last longer. Football players are also at a greater risk of tearing muscles as they play a contact sport. Marathon runners are at less of a risk because there is no contact in their sport and the majority of their injuries occur from not adequately stretching. Football players use their fast twitch muscles much more than their slow twitch muscles as they have to sprint for a short amount of time, then they have a short break before the next play. Marathoners use their slow twitch muscles more because they need to be able to last for a long time on their energy.
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AuthorMichael Tellini Archives
May 2014
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