IS2 Test Review with Answers
- 2. Body Organization and Homeostasis – Ch. 1-11. How is the body organized? Give an example of each level.Systems, organs, tissues, cellsExample: digestive system/ organ: stomach /tissue: muscle tissue2. What is homeostasis?Process in which the body maintains its internal environment stable despite external conditionsExamples: controlling amount of CO2, urea, sugar, water / controlling temperature
- 3. Nutrition – Ch. 21) What are nutrients? Why do we need them?Substances needed to help the body function well/carry out its processesExamples: to build bones, teeth and muscles, to help the immune system work, 2) How many calories should an average adult have per day?around 2000kcal3) What is the importance of carbohydrates?They store short term energy4) Compare simple and complex carbohydrates. Give an example of each.Simple carbs are small molecules, like glucose.Complex carbs are bigger molecules made of simple carbs. Example: starch (made of glucose)
- 4. 5) What are fats used for?Store long term energyProvide thermal insulationMake up cell parts6) Compare saturated and unsaturated fats. Give an example of each.Saturated fats are solid at room temperature, like butter.Unsaturated fats are liquid at room temperature, like oil.Too much saturated fat in blood can clog vessels.7) What do proteins do in our body?They make up our body structure: muscle, hair/nails (keratin), skin (collagen)(needed for tissue growth)They help defend our body: antibodies are proteins that help fight diseasesThey help carry substances like oxygen throughout our body (hemoglobin)Play a role in chemical reactions (enzymes are proteins!)8) What are proteins made of?Proteins are long chains made of small units called amino acids
- 5. 9) What are vitamins? Why are they important? Give examples and their functions.Vitamins are organic substances (made by living things).They regulate chemical reactions in our body.Vit. C – helps immune systemVit. D – helps bone formationVit. A – helps visionVit. K – helps blood clotVit. B – helps regulate metabolism10) What is the difference between fat-soluble and water-soluble vitamins?Fat-soluble vitamins: are dissolved in fats in our bodyWater-soluble vitamins: are dissolved in water in our body 11) Why are minerals important? Give examples and their functions.Minerals help regulate the metabolism.Calcium: helps bone formationSodium: regulates blood pressurePotassium: helps muscle contractionIodine: helps the thyroid produce hormones12) Why is water essential to life?Chemical reactions need water to happen.Water helps cool the body (sweat / homeostasis)13) A healthy diet should have...A balanced amount of different nutrients (not too much fat)
- 6. Digestion – Ch. 2 1) What are the jobs of the digestive system?To break big nutrients into smaller ones To absorb the small nutrientsTo eliminate the waste2) What nutrients don’t need to be digested? Why?Vitamins and minerals. Because they are so small they can be absorbed directly in the small intestine.3) Compare chemical and mechanical digestion.Mechanical digestion: change in shape/size of the food. Still the same food. Ex. teeth chewing foodChemical digestion: change in the type of molecule. Enzymes help break down nutrients into their smaller units: Proteins into amino acids Starch into simple sugars Fats into fatty acids4) What are enzymes and what do they do? What factors affect their job?Enzymes are proteins that speed up the chemical reactions in the body.Enzymes are not affected in the process.Enzymes can have their shape changed by heat and by a change in the pH of the environment
- 7. 5) Talk about chemical and mechanical digestion of nutrients in the mouth. Mechanical: chewing/teethChemical: saliva contains water and amylase. Water helps moisten the food to facilitate its movement throughout the digestive system Amylase is an enzyme that helps break down starch into simple sugars6) What is the importance of the epiglottis? Where is it located?The epiglottis is a flap that closes the passage of food to the trachea. It’s located in the entrance to the larynx.7) What is peristalsis? What is its importance? Where does it happen?Involuntary muscle contractions that help push food along the digestive tube.It happens in the esophagus and in the intestines.8) Talk about chemical and mechanical digestion of nutrients in the stomach.Mechanical: mixing/churning food due to muscle contractionsChemical: pepsin (protease) breaks down proteins into amino acids with the help of hydrochloric acidMucous protects the stomach wall against the acid.
- 8. 9) What does the liver produce? Where is it stored? Where is it released? What is its importance?The liver produces bile which is stored in the gallbladder and released into the small intestine.It helps the digestion of fats by breaking big droplets of it into smaller ones so enzymes can break fats into fatty acids10) What does the pancreas produce? Where is it released?All kinds of enzymes (amylase, protease, lipase) + bicarbonate (alkaline)They are released into the small intestine11) What are the jobs of the small intestine?Finish digestion (with bile + pancreatic juice)Absorb nutrients12) What are the villi and how are they important?The villi are folds that line the wall of the small intestine. They increase the intestine’s surface area to allow MORE nutrients to be absorbed13) What happens in the large intestine?Absorption of waterProduction of vitamin K by bacteria
- 9. Circulation – Ch. 31) What makes up the cardiovascular system and what is its job?The heart, blood vessels and the bloodIt’s job is to transport needed materials throughout the body, to remove waste and to help the immune system (by carrying white blood cells and antibodies)2) What is the heart’s job? Describe its structure.To pump blood to the lungs and the body.There are four chambers: 2 atria (upper) and 2 ventricles (bottom)3) Explain the flow of blood inside the heart using the ‘two loops’ model.Loop 1: blood flows from the right side of the heart to the lungs and back to the left side of the heart.Responsible for taking blood rich in CO2 to the lungs and bringing blood rich in O2 to the heart.Loop 2: blood flows from the left side of the heart to the body and back to the right side of the heart.Responsible for taking blood rich in O2 to the body and bringing blood rich in CO2 to the heart.4) What is the importance of the valves?They prevent the backflow of blood in vessels/inside the heart
- 10. 5) Why does the left ventricle have thick walls?The left side of the heart pumps blood to the whole body. It needs a stronger ‘push’ .6) What is the pacemaker? What does it do?A region in the right atrium that generates a contraction7) What are arteries? Describe their structure.Arteries take blood away from the heart. They have a thick muscle layer to help prevent damage (due to strong pressure) and to help push the blood forward with a stronger pressure.8) What are veins? Describe their structure.Veins take blood back to the heart. They have a thin muscle layer and a wider space inside to help blood flow with lower pressure.9) What are capillaries? Describe their structure.Capillaries are tiny vessels that connect arteries and veins and allow exchange between the blood inside them and body tissues.They have a small width and a one-cell-thick wall.
- 11. 10) How do nutrients move from capillaries to cells and backwards?Nutrients move through diffusion (from high to low concentration)11) What causes blood pressure?The force of the blood inside the vessel12) What is present in blood?Plasma, red blood cells, white blood cells, platelets13) What is the importance of plasma? What is in it?It is mostly made of water and it’s where most substances are dissolved.Contains nutrients, oxygen, carbon dioxide, urea, salts, antibodies, heat14) What do red blood cells look like? What do they do? Where are they made?Round and flatThey transport oxygenThey are made in the bone marrow15) What is hemoglobin?A protein found inside the red blood cell that is responsible for transporting oxygen
- 12. 16) What do white blood cells do? Where are they made?They are cells that fight germs and help defend our body.They are made in the bone marrow.17) What are platelets? What do they do?They are cell fragments that help form blood clots18) What is the lymphatic system? What is its job?Is a group of vessels that help transport excess water back to the circulatory system19) What do lymph nodes do?Lymph nodes are small knobs of tissue that filter lymph, trapping bacteria and other pathogens in the fluid 20) What is atherosclerosis? What is its consequence?It’s the build up of fatty materials inside our blood vesselsBlood vessel walls thickenLess blood flows in vesselVessels can clog and rupture (heart attack/stroke)
- 13. 21) What is a heart attack?Condition in which the flow of blood is blocked in part of the heart muscle causing the cells to die and the contraction to stop 22) What is hypertension? How can you control it?High blood pressureYou can control it by eating less salt23) How exercise, diet and smoking affect your cardiovascular health?Exercise makes the heart stronger, improves the circulation of blood and the vesselsA diet rich in fats can contribute to the build up of plaque inside vessels (heart attack/stroke)Smoking increases the blood pressure = greater chances of stroke/heart attack
- 14. Respiration – Ch. 41) What is the job of the respiratory system?To bring oxygen from the environment into the blood so the cells can break the sugar and get energy (cell respiration)To remove CO2 from the blood out to environment2) What is the path or air in our body?Mouth/nasal cavity – pharynx – larynx – trachea – bronchus – bronchioles – alveoli3) What is the advantage of breathing through our nose instead of mouth? (cilia, mucous, hair, heat)Hair and Mucous: traps germs/dust/particles of dirt before they reach the lungsCilia: help remove the mucousHeat: air is warmed up and moistened = less irritation on the lining of the respiratory tract/decreases chances of infections4) What are the roles of the mucous and the cilia found in the trachea? (and nasal cavity + bronchus)Mucous: traps germs/dust/particles of dirt before they reach the lungsCilia: help remove the mucous5) The lungs are made up of...Billions of tiny sacs called alveoli
- 15. 6) Describe the alveoli’s features and their importance. Single celled wall: gas exchange is faster/shorter distance for O2 and CO2 to moveMoist: helps gases diffuseLarge surface area: allow more gas diffusion7) Explain how gas exchange occurs.CO2 moves from the blood into the alveoliO2 moves from the alveoli into the bloodThe movement is called diffusion8) Describe the steps involved in inhaling.Diaphragm contractsRib cage risesRib cage volume increasesLess pressure inside rib cageAir enters the alveoli9) What are the vocal cords? What do they do?Flaps of tissue that vibrate as air moves through them allowing sounds to be produced10) How do these chemicals found in cigarette – tar, carbon monoxide, and nicotine – affect your body?Tar: sticky substance = alveoli stick together = less space for fresh airCarbon monoxide: sticks to red blood cells making them useless = can’t transport O2 anymoreNicotine: addiction/stimulant = increases blood pressure 11) What is bronchitis?Irritation of the bronchioles = small passages of air become narrower than normal and clogged with mucous12) What is emphysema? What is the consequence of this?Destruction of lung tissue caused by the smoke in cigarettes = cause breathing difficulties
- 16. Excretion – Ch. 41) Define excretion.Removal of waste from the body2) Outline the job of the excretory system.To filter the blood and remove urea3) Define urea.Chemical that comes from the breakdown of proteins4) List the organs that make up the excretory system and describe their functions.Kidney - contains the filtering units Ureter – takes urine from kidney to bladderBladder – stores urineUrethra – takes urine away from the body5) Define nephron.Small filtering unit present in the kidney6) Explain the sentence: “the nephron filters wastes in stages”.First = small substances go through the capillaries/nephron capsule (some useful substances also go through – like glucose and water). Second = glucose and most water are reabsorbed into the blood (cannot be wasted). Urea, some salts and some water make up the urine.
- 17. 7) Why do you think blood cells and proteins are not filtered by the kidneys? Explain.They are too big to cross the capillary’s pores/go through the kidney capsule8) What kind of problems can be detected with a simple urine test? How do doctors detect these problems?Presence of proteins (damage to kidney?), presence of white blood cells (infection?), presence of sugar (diabetes?)9) Explain how the kidney helps maintain homeostasis.It helps regulate the amount of water in the bodyIt helps regulate the amount of urea (waste) in the body10) Explain how the lungs and skin help maintain homeostasis.Lungs = help release CO2 (waste), some waterSkin = helps release water/sweat carrying heat from the body (controls body temperature)11) Explain how the liver helps maintain homeostasis.Liver turns toxic substances into less harmful ones