Review: Human Body Systems
Vocabulary
Cell: smallest unit of living things
Tissue: a bunch of cells working together to do the same job
Organ: a bunch of tissues working to do the same job
Organ system: a bunch of organs working together to do the same job
Organism: a group of organ systems working together to help an individual maintain homeostasis
Processes of Life
homeostasis: balanced internal environment
metabolism: the rate at which food is broken down into energy
nutrition: intake of organic molecules to supply essential materials for survival
digestion: breaking down food to simple sugars (from starches) so it can enter thecells
respiration: making energy from oxygen and food OR the act of exchanging oxygen for carbon dioxide
circulation: movement of essential materials and wastes through the body
excretion: removal of all waste products made by the cells
movement: locomotion or movement from place to place
coordination: send and respond to chemical messages and electrical impulses to keep the body moving
immunity: the body’s ability to resist and fight disease
reproduction: making more of the same organism
enzymes: proteins responsible for building or breaking down organic moleculesand work based on fitting into their substrate molecule (if it doesn’t fit it doesn’t work!)
hormones: chemicals that respond through feedback loops to send messages throughout the body, they work based on fitting into receptor molecules on cells (if it doesn’t fit it doesn’t work!)
Comparison Chart:
Function / Single Cell / Multicellular organismGas exchange / Cell membrane / Respiratory system
Transport of substances / Cytoplasm / Circulatory system
Nutrition / Vacuoles, chloroplasts / Digestive system
Respiration / Mitochondria / Circulatory and respiratory system working together
Reproduction / Nucleus / Reproductive system
Immunity / Lysosomes / Immune System
Movement/locomotion / Cilia or flagella / Skeletomuscular system
Immunity Specific Vocabulary:
Pathogen: an organism (virus, fungus, bacteria) that causes disease
Antigen: chemical produced by a pathogen
Antibody: chemical made by white blood cells that recognizes antigens and marks pathogens to be killed by white blood cells
White blood cells: cells that fight off disease by making antibodies or destroying pathogens
Resistant: ability to fight off or survive
Transplant: replacing a malfunctioning organ with one from another organism
Immunosuppressant drugs: medicines that keep the immune system from
responding and not accepting a donated organ
Vaccine: a weakened or dead pathogen injected into the body to force antibody production so that someone won’t get sick in the future
Antibiotic: medicine used to fight off harmful bacteria
Immune Response: When the body is infected with a pathogen, there is an incubation period: that means that the pathogen needs time to reproduce in our body and overcome our immune system before we will start to show signs and symptoms of being sick. During that period, our body is working hard to fight off the pathogen using the following methods:
Organ transplants work much like a pathogen: the new organ makes different chemicals that our organs so the body tries to fight off and kill the new organ the same way it would a pathogen (triggers an immune response). Doctors will use immunosuppressant drugs that shut down the immune system until the body recognizes that the new organ is not trying to hurt them. This is why stem cell research is being pushed: they could use it to clone organs from the individual and replace the non-working one that is the exact same!
Allergies are related to both of these. Everything that we eat or come in contact with makes their own chemicals (proteins). Where most people may not have issues with things like peanuts, pollen, and animal dander, some people’s bodies see the proteins made by these things as dangerous and will react to them just like they were pathogens. Instead of the chemicals being called antigens, we call them allergens. It is easy to see the difference between a sickness caused by an allergen or by a pathogen because if you remove the source of the allergen, the person will get better in a short amount of time.
Vaccines work based on the immune response. A vaccine is a weakened or dead form of the pathogen. When we get a vaccine (shot or immunization), the doctor is giving you a disease. This forces your body to make the antibodies to fight it off and kill it. Antibodies stay in your blood stream forever, so if you are ever exposed to the disease again, it will fight it off before you even know that you have it!
Antibiotic resistance is based on evolution. Pathogens are living things too, so they want to survive just like we do. When we take antibiotics for a bacterial infection, they will kill off bacteria, but some bacteria have evolved to be harder to kill. If the antibiotic is not strong enough OR the bacteria has mutated so that the antibiotic doesn’t fit with the receptor site anymore, the bacteria will continue to reproduce and make you sick. You will need a stronger antibiotic or wait until your immune system makes the antibodies and white blood cells before you get better. Sometimes you will feel better after taking an antibiotic for 3 of the 10 days that the doctor told you to take it. It is important to take it for the full 10 days to make sure both the least resistant and the extremely resistant bacteria are killed off or else you will get sick again AND it will be caused by the bacteria that is the hardest to kill.
Pesticide resistant or Insecticide resistant insects (bugs) respond the same way as antibiotic resistant bacteria. Any questions based on this can be answered the same way you would answer for the bacteria!
Hints:
When studying, do NOT focus on each of the body systems….. simply know what each system does.
DO focus on hormones, enzymes, immunity, and the reproductive system as this will be the majority of the questions from this unit.
Practice Questions, Human Body Systems
1. Which sequence represents the correct order of events for the production of necessary complex molecules after food is taken in by a multicellular animal?
(1) diffusion -->synthesis -->absorption -->digestion -->circulation
(2) circulation -->diffusion -->synthesis -->absorption ->digestion
(3) digestion -->absorption -->circulation -->diffusion -->synthesis
(4) synthesis -->digestion -->absorption -->diffusion --> circulation
2. The interaction of which two systems provides the molecules needed for the metabolic activity that takes place at ribosomes?
(1) digestive and circulatory
(2) reproductive and excretory
(3) immune and nervous
(4) respiratory and muscular
3. Which system is correctly paired with its function?
(1) immune system—intake and distribution of oxygen to cells of the body
(2) excretory system—remove potentially dangerous materials from the body
(3) digestive system—transport energy-rich molecules to cells
(4) circulatory system—produce building blocks of complex compounds
4. When a new viral infection appears in a population, scientists usually try to develop a vaccine against the virus. Which substances would most likely be contained in the new vaccine?
(1) live bacteria that ingest viruses
(2) white blood cells from an infected individual
(3) weakened viruses associated with the infection
(4) a variety of microbes that will attack the virus
An investigation is carried out to determine the effect of exercise on the rate at which a person can squeeze a clothespin.
5. In this investigation, the independent variable is the
(1) control
(2) exercise
(3) rate of squeezing
(4) number of participants
6. Muscle fatigue occurs during this activity when
(1) carbon dioxide is used up in the muscle cells
(2) simple sugar is converted to starch in the muscle cells
(3) proteins accumulate in mitochondria in the muscle cells
(4) certain waste products collect in the muscle cells
7. Which situation indicates a serious organ system malfunction?
(1) The ovary releases estrogen, which quickly binds to cell receptors.
(2) Blood flow throughout the entire body is suddenly reduced.
(3) White blood cells release enzymes in response to the proteins on inhaled pollen.
(4) Mitochondria stop functioning in a unicellular organism exposed to pollutants.
8. Drugs to reduce the risk of rejection are given to organ transplant patients because the donated organ contains
(1) foreign antigens
(2) foreign antibodies
(3) DNA molecules
(4) pathogenic microbes
9. Which body system is correctly paired with its function?
(1) excretory—produces antibodies to fight disease-causing organisms
(2) digestive—produces hormones for storage and insulation
(3) circulatory—transports materials for energy release in body cells
(4) respiratory—collects waste material for digestion
10. The failure to regulate the pH of the blood can affect the activity of
(1) enzymes that clot blood
(2) red blood cells that make antibodies
(3) chlorophyll that carries oxygen in the blood
(4) DNA that controls starch digestion in the blood
11. To replace burned skin, doctors can successfully transplant replacement skin taken from another part of the body of the burn victim. Which statement best explains why the transplanted skin is not rejected?
(1) The transplanted skin is damaged, making the immune system nonfunctional.
(2) The antigens of the replacement skin are the same as those of the damaged skin.
(3) Burn victims lose so much blood that white blood cells cannot cause an immune response.
(4) There is no blood supply to the skin, so mixing of antigens does not occur.
12. The ability of the human body to keep blood sugar levels within a fairly narrow range, despite the intake of meals high in carbohydrates, is an example of
(1) active transport
(2) genetic recombination
(3) homeostasis
(4) digestion
13. A vaccine used against an infectious disease may contain
(1) specialized blood cells
(2) toxic enzymes
(3) a variety of antibiotics
(4) weakened pathogens
14. Which activity would stimulate the human immune system to provide protection against an invasion by a microbe?
(1) receiving antibiotic injections after surgery
(2) choosing a well-balanced diet and following it throughout life
(3) being vaccinated against chicken pox
(4) receiving hormones contained in mother’s milk while nursing
15. Certain microbes, foreign tissues, and some cancerous cells can cause immune responses in the human body because all three contain
(1) antigens (3) fats
(2) enzymes (4) cytoplasm
16. Some diseases and their causes are listed below.
A. Flu—influenza virus
B. Lung cancer—smoking
C. Cystic fibrosis—genes
D. Dysentery—parasitic ameba
Which disease would individuals have the greatest difficulty preventing in themselves?
(1) A (3) C
(2) B (4) D
17. The diagram below shows a cell in the human body engulfing a bacterial cell.
The cell labeled X is most likely a
(1) red blood cell (3) liver cell
(2) white blood cell (4) nerve cell
18. Viruses frequently infect bacteria and insert new genes into the genetic material of the bacteria. When these infected bacteria reproduce asexually, which genes would most likely be passed on?
(1) only the new genes
(2) only the original genes
(3) both the original and the new genes
(4) neither the original nor the new genes
19. Which statement best describes how a vaccination can help protect the body against disease?
(1) Vaccines directly kill the pathogen that causes the disease.
(2) Vaccines act as a medicine that cures the disease.
(3) Vaccines cause the production of specific molecules that will react with and destroy certain microbes.
(4) Vaccines contain white blood cells that engulf harmful germs and prevent them from spreading throughout the body.
Stem cells present in an embryo are responsible for the formation of various tissues and organs. Recent research suggests that it may be possible to replicate stem cells from sections of skin taken from adult mice, rather than having to use stem cells from the embryos of mice. In the future, human stem cells may be used to replace human tissue damaged by diseases such as Parkinson’s disease and multiple sclerosis.
20. Discuss why the use of stem cells taken from a patient to replace damaged tissues and organs may decrease the potential risk to a patient. In your answer, be sure to:
• identify the major problem that may occur when tissues and organs donated by another individual are used [1]
• explain why this problem may occur [1]
• explain why this problem will not occur if tissues and organs produced by stem cells from the patient are used [1]
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21. The table below lists enzymes that function in different locations in the human body, and the temperature and pH ranges of these locations.
Different enzymes are secreted in each of the three locations. Ptyalin digests carbohydrates. Pepsin and trypsin both digest proteins. Discuss the activity of these
enzymes. In your answer, be sure to:
• state how the activity of pepsin will most likely change after it moves with the food from the stomach to the small intestine [1]
• support your answer using data from the table [1]
• state how a fever of 40°C would most likely affect the activity of these enzymes and support your answer [1]
• identify the characteristic of enzymes that prevents ptyalin and trypsin from digesting the same type of food [1]
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A normally healthy 35-year-old woman was found to have a severe intestinal infection usually seen in much older and sicker patients in hospitals. Because of so many cases like hers, some doctors became alarmed that the organism responsible could spread rapidly and cause unusually severe illnesses and some deaths. Scientists suspect that thecause is a mutated form of an organism that has a resistance to some of the most common treatments.
22. Since it is difficult to cure an infection caused by this organism, it might be easier to prevent these infections by using a vaccine. Identify the specific material a vaccine would have to contain to prevent future infections. [1]
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23. Explain how this vaccine would prevent future infections. [1]
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24. The mutated form of this type of organism could result from a change in a molecule within one member of the original population. Identify the molecule. [1]
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25. Staphylococcus aureus is a type of bacterium that lives on the skin and in the nostrils of most people. Generally, it is controlled by the immune system of the body.
Occasionally, the antibiotic penicillin is needed to control the bacterium. However, some strains of S. aureus have a resistance to penicillin, which makes them hard to kill
and infections difficult to cure.
Explain how the resistance to penicillin affects the S. aureus population. In your answer, be sure to include an explanation of:
• how the exposure to penicillin affects the survival of some bacteria in the population
[1]
• why the frequency of penicillin-resistant bacteria can change over time within the population [1]
• how it is still possible to cure patients who are infected with penicillin-resistant bacteria [1]
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To most people, using maggots (fly larvae) for a medical treatment is not a great idea. However, to many doctors, fly larvae do have a place in medicine, and that place is inside open wounds. In maggot debridement therapy, live fly larvae are mixed into a dressing for a wound and the area is covered with gauze. Maggots, which will only eat dead tissue, feed on damaged flesh and leave the healthy tissue behind. In the process, the maggots excrete an antimicrobial chemical that helps cleanse the wound of pathogens. When the dressing is cut away two or three days later, the maggots, now up to 10 times their original size, are easily removed. People with diabetes often have impaired wound healing. This could lead to infection. Maggot therapy has been used to clean these types of wounds.
26. What is the meaning of the term debridement?
(1) excretions of pathogens
(2) impaired wound healing
(3) removal of dead tissue
(4) destruction of antimicrobial chemicals
27. Which group of terms best describes a maggot?
(1) decomposer, prey, host
(2) scavenger, heterotroph, consumer
(3) producer, predator, parasite
(4) pathogen, carnivore, autotroph
28. State one possible reason why slow healing of wounds can lead to infection. [1]
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29. Two life functions performed by all living organisms are nutrition and respiration.
Identify two other life functions that are essential for the survival of all living organisms.
Explain how each of the two life functions you identified maintains homeostasis. [2]
Life Function: ______
Explanation: ______
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Life Function: ______
Explanation: ______
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Many people have a sensitivity to peanuts. The symptoms can include watery, itchy eyes and difficulty breathing. This allergic reaction can be mild, severe, or fatal.
30. Discuss why an individual can have a sensitivity to peanuts. In your answer, be sure to:
• identify the human system that is responsible for this sensitivity to peanuts [1]
• identify the specific type of molecule that triggers an allergic reaction [1]
• state one reason why a person could be allergic to peanuts, but not be allergic to walnuts [1]
• describe how this reaction is similar to the rejection of a transplanted organ [1]
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Proteins on the surface of a human cell and on a bird influenza virus are represented in the diagram below.
31. In the space below, draw a change in the bird influenza virus that would allow it to infect this human cell. [1]