AP Biology Summer Summaries There are many differences between proximate and evolutionary causes and explanations on why we are such easy targets for diseases. The proximate explanations are described by its anatomy, physiology, and biochemistry. Evolutionary explanations go into detail on what would happen if we didn’t have the genes that cause us to get sick. Proximate causes look for what genes it is made up of and how it works. Evolutionary causes are why natural selection hasn’t eliminated the genes that cause us harm.
For example the author uses the example of how with arrogate causes our taste buds detects saltiness, sweetness, sourness, and bitterness then sends it to the brain to analyze it. But with evolutionary causes it detects saltiness, sweetness, sourness, and bitterness then sends it to the brain to help us cope with either our emotional or physical wants or needs. We would want to correct out defects because that would mean getting rid of our problems that prevent us from functioning properly.
But even with these defects gone we wouldn’t our defenses to disappear because there are always new diseases around that our body hasn’t come across yet, so our defenses would allow us to face the most unpredictable environments without it being deadly but without our defenses we can get can get sick or even worse. The “outlaw’ gene are genes that create their own way of spreading/growing at the expense of person or specie it inhabits. This in return shows the selection of genes acts only to benefit the genes and not the person or species. Chapter 1) Natural Selection will change a gene characteristic such as color or size if it will help the survival rate, it all depends on the current in environment that the gene is in. For example IF the tendencies to anxiety, heart failure, nearsightedness, gout, and cancer meow increased reproductive success than those genes would be selected even if we suffer. Natural selection is also process which biological traits best adapted to their environment and transmit their genetic characteristics by in increasing numbers.
If the INDIVIDUAL gene code has characteristics that result in fewer offspring, that gene is gradually eliminated. This shows that natural selection is only out to benefit the groups and do what is better for the body. When Holland said “No, not for one brother. But I would for two brothers, or eight cousins. ” when talking about sacrificing himself he was talking about the numbers. When you have a sibling they share half of each others genes and cousins share one eighth of each other genes.
So Holland was referring to that if would save a group of people who make all up all of his genes so 8 of his cousins or 2 siblings that way his genes still have a chance at reproduction. The Adaptations Program are methods of investigating the studies of the functional reasons for human attributes. (Chapter 2) Throughout the chapter the author explains that fever are mostly good for our bodies. It explains that divers are the bodies way tot curing itself in the book it states “fever is unpleasant but useful.
It is an adaptation shaped by natural selection specifically to fight infection” but we find having fever is troublesome so we take medicine to get rid of the problem. But the problem with that and having a fever is the medication. The medication can block fever and interfere with the normal mechanisms that regulate the body’s response to the infection. In the book it states “Fever will sometimes rise too much and other times not enough”. So when dealing with a fever balance is actually the key.
Iron levels are very important when talking abut infections and how to control them, Iron is crucial and scarce resource for cetera so having to much can help the “bad” bacteria survive longer and multiply but having to little iron can kill of important cells and cause many problems such as diabetes and anemia. The author explains many different types of defenses, One he discussed was Hygiene and how by simply swatting a mosquito or washing our hands can prevent things such as malaria or the flu. Our tendencies to avoid things that “disgust” us is our natural way to prevent diseases and infections.
Another type of defense is the Skin, which protects us from “mechanical, thermal, and chemical forces. For example “Any part of the skin that is constantly under stress, like the tip of a cellist’s finger it grows thicker skin called callus which prevents the break of skin that could let pathogens Macrophages constantly wander the body searching for any foreign protein, whether from bacteria, dirt in the skin, or a cancer cell. A helper T cell is who the macrophages reply the message to if an intruder is found and it activates the antibody.
An antibody is white blood cells that can make a protein called antigen. A antigen is a foreign protein that induces the production of antibodies. Our body recognizes its own cells because each cell has a molecular pattern on its surface called, major historiography’s complex (MUCH). If a cell has the correct MUCH it is left alone but if the cell doesn’t have a MUCH or it is incorrect thy are attacked. A compensatory adjustment is basically when when give something or negotiate and expect results for example in the book it states ” chewing on your left side of your mouth, if it hurts to chew on the right side”.
One way that pathogens can evade the bodies defenses is to gain entrance to cells by appearing to offer them meeting they need like oxygen, protein, etc. (Chapter 3) The “Red Queen Principle” is basically evolution becoming more complex and difficult in the book it gave an example of a rabbit and a fox, if the fox becomes a faster runner then the rabbit has to run faster too, and if the fox has better eyesight then the rabbit has to blend in more with background and so on and so on.
We humans have a great disadvantage in the arms race because according to the author bacteria can evolve as much in a day as we can in a thousand years, and because of this we cannot evolve fast enough to escape from microorganisms. Plasmids are tiny rings of DNA that leave some its DNA behind as a new part of the bacterial genome/ makeup. So when we try to treat diseases or infections it may only work a couple times because if the plasmids keep keep leaving a trace of the cure then it will become more and more resistant.
Bacterial resistance to antibiotics arises by the rare gene mutations or new genes introduced by plasmids. So, yes gene mutation can be transmitted by plasmid infection or other processes to different species of bacteria. Paul Lead discovered that diseases trot vector-borne pathogens tend to be more ever than those spread by personal contact and that mosquito borne infections are generally mild in the mosquito and severe in vertebrate hosts. (Chapter 4) Pain and Fear are very useful and people who don’t feel pain and fear are considered severely handicapped. Both pain and fear fear are signals that warn us of danger.
Pain is the signal that tissue is being damage, and Fear is a signal that a situation may be dangerous and some kind of loss or damage is likely. The Lanterns cells in the epidermis(skin) are used to take up foreign substances and present the immune system to fight them off. The XIV-B radiation depletes the skin of these cells and results in blocking the ability to react to contact with foreign proteins. There are a few things such as sunscreen that block some but not all UP-rays. The author gives many reasons of why we arena able to regret a lost finger or any other type of body part.
One explanation that is merely that this regenerative ability would not be used very often and would not produce a major benefit. Another reason is the capacity to regenerate damaged tissue demands not only the cost of maintaining the machinery to make this possible but the cost of a decreased ability to control harmful growths s well. (Chapter 5) The seeds within the fruit are designed either to be discarded intact or to pass safely through an intestinal tract, if the fruit is eaten before the seeds are ready all the time would wasted.
So many plants poisons to discourage consumption of immature fruits. Us humans protect ourselves from ingesting harmful toxins such as plant toxins by avoiding things that taste bad because we react with an adaptive disgust to the toxins produced by fungi and bacteria. We rapidly expel toxic substances by spitting, vomiting, or diarrhea. We quickly learn to avoid whatever gives us nausea or rehear. Novel toxins are a special problem for us because some EDT are extremely different chemically from those with which we are adapted to cope.
Mutagens are chemicals that cause mutation, which may caused cancer or damage genes and result in to health problems for many generations. Teratology are chemicals that interfere with normal tissue development and cause defects. According to Margin Profit a biologist from from Seattle, morning sickness is a result of nausea and food aversions during pregnancy evolved is to impose dietary restrictions on the mother and thereby minimize exposure to toxins. Chapter 6 ) Every DNA molecule is like a ladder with each side made up of alternating units of phosphate and didgeridoos.
The information within DNA is found in the rungs and each gene codes for four molecular components with names abbreviated A, C, G, and T. If a defective allele is a dominant allele, one copy of it will cause disease. If a defective allele is a recessive allele then it will have no noticeable effect if it is paired with the normal allele. The genotype is what genes an organism has for a specific trait. The phenotype has to do with organism physical traits as a consequence of the interaction of its genotype and the environment. Homozygous is when both alleles are same and heterozygous means that both alleles are not same.
Natural selection hasn’t been able to eliminate these genes like Huntington because natural selection doesn’t select tort Neal TN, but only tort reproductive success and it a gene doesn’t reduce the average number of surviving offspring then it may remain common even though it causes devastating sickness. Heterozygous advantage is when heterozygous have increased fitness over both homozygous. (Chapter 7) Senescence is the process of bodily deterioration that occurs at older age. SOD is superposed diastase. SOD is a compound that neutralizes free radicals before they can cause much damage. Lack of SOD may cause metamorphic lateral sclerosis.
The reason males don’t live as long as females is that male reproductive success is dependent on competitive ability that male physiology is devoted more to competition and proportionately less to preservation of the body. (Chapter 8) The structure of our respiratory system & digestive systems makes us susceptible to medical problems because our mouth is below and in front of our nose but our food-conveying esophagi is behind the air conveying trachea in our Hess, and this means the tubes must cross in the throat, and this is what makes us prone the medical problems. The problems posed by the positioning of our retina are blind spots.
The problems that are posed by the positioning of our retina is the blood vessels on the retina cause the cast of shadows that create many blind spots and if any bleeding or obstruction of blood flow in the retina also casts a shadow that may seriously impair the visual image. There are many problems that come from being upright, one is the weight of the top of our body compresses the vertebrae in the rower spine and the second requires more muscular effort. (Chapter 9) Fewer people die young from smallpox, appendicitis, childbirth complications, and hunting accidents are the reasons why death rates from old afflictions are much higher now.
We might “crave” higher fat foods because they were short in supply through our evolutionary history and everyone would’ve been better off with more of these substances. Presently, most people can afford to eat more fat, sugar, and salt than is biologically adaptive. Thrifty genotype is a genetically based ability to get and store food energy with unusual efficiency. A disadvantage it may confer today is that they are not adaptive in a world in which food shortages never occur. Humans living in cold environments are indoors most of the day and covered with clothes when they go outdoors so the amount of vitamin D they synthesize will be tiny.
Humans need sun exposure on their skin because vitamin D needs to synthesis. (Chapter 10) The most widely accepted view is that the leg system is there to fight parasitic worms. Profit’s explanation of the leg system is that it evolved as a backup defense against toxins. A topic are people who are especially susceptible to allergies. (Chapter 1 1) The relationship between cancer and menstrual cycles is the probability of a cancer of the female reproductive system at any age increases because of the relation to the number of menstrual cycles a woman has experienced.
The person who would most likely to get cancer of the reproductive tissues is an elderly woman who had an early menarche and late menopause and never had her menstrual cycle disrupted by pregnancy and lactation. (Chapter 1 Gametes face difficulties which are that they must have sufficient energy stores there are major difficultly that they both to endure until they merge with another gamete ND to nourish a developing embryo, and also they must find another gamete. Eggs are larger than sperm because they are produced as large gametes.
Concealed ovulation protects the woman somewhat from being impregnated by men who more powerful because men can’t know when women are fertile and take advantage of her at that time. Genetic imprinting is when a gene is somehow conditioned by its parent either to start acting immediately or to avoid acting in the offspring. The purpose of hug in human pregnancy is it helps the fetus not to contest with its mother so the pregnancy can continue on. The possible explanation for babies having colic is that gastrointestinal difficulties are responsible.
The number one cause in the death of babies is KIDS (sudden infant death syndrome). The incidence of KIDS in babies is 1. 5 per 1000 babies die or more than 5000 a year in the United States. (Chapter 13) Anxiety can be advantageous because it can alter our thinking, behavior, and physiology. We aren’t anxious all the time because discomfort is maladaptive but because anxiety uses extra calories makes us less fit for many everyday activities and damages tissues. Manic-depressive disorder is a condition in which mood swings wildly from the depths of depression to aggressive euphoria.