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Study Guide for BIO 120 v1.0
Lecture Exam 3: Homeostasis

Multicellular Organisms:
[6th & 7th eds CH 16.21, CH 18.1, CH 20.1—8, 10, 13; CH 31.5]

1. What is multicellularity and where do we find it among living things?
Multicellular organisims-seaweeeds, plants, animals and most fungi- are fundamentally different from unicellular ones.

2. Why do we think multicelled animals evolved from a colony of single-celled eukaryotes?
Because the oldest known fossils of multicellular eukaryotes are small multicellular alge. Fossil record remains show that about 600 million years ago, a variety of multicellular alge had evolved, along with some soft bodied animals resembling corals, jellies and worms.

3. Know the definitions of the terms: organ system, organ, tissue and cell, and recognize examples of each level of biological hierarchy (e.g. the heart is an organ).
Organ system: Consists of multiple organs that together perform a vital body function.
Organ: Made up of two or more types of tissues that together perform a specific task.
Tissue: An integrated group of similar cells that perform a common function.
Cell: A basic unit of living matter separated from its environment by a plasma membrane; the fundamental structural unit of life.

4. What are the 4 organs and 3 tissue types in plants? What are their functions?
3 Tissues
1. Dermal—protection
2. Vascular—transport water and nutrients
3. Ground—food storage, support, photosynthesis
4 Organs
1. Roots—anchor in soil, absorb water & nutrients
2. Stems—support, transport
3. Leaves—photosynthesis
4. Flowers—reproduction

5. Know the structure and function of the four types of tissues in animals.
a. Epithelial Tissue
-Layered sheets of tightly packed cells
-Cover body surfaces, interior and exterior!
b. Muscle Tissue
-Bundles of striped fibers
-Performs movement
-Most of body tissue in animals
c. Nervous Tissue
-Neurons are nerve cells
-Conducts electrical impulses
-Transmits sensory information
d. Connective Tissue
-Sparse population of cells in a “matrix”
-Diverse structures & functions
6. What are the functions of the reproductive, circulatory, digestive, respiratory, excretory, nervous, immune, integumentary, muscular, skeletal, and endocrine systems? Which ones work closely together to do a shared job?
Reproductive system: Produces gametes and sex hormones. The female system provides organs to support a developing embryo and glands for producing milk.
Circulatory: Delivers nutrients and oxygen (02) to body cells and carries carbon dioxide (CO2) to the lungs and the kidneys.
Digestive: Ingests and breaks down nutrients and eliminates waste.
Respitory: Exchanges gasses with the environment supplies blood with O2 and disposes CO2.
Excretory: Removes nitrogen-containing waste products from the blood and regulates the chemical makeup, ph and water balance of the blood.
Nervous: ordinates body activates by detecting stimuli, integrating info and directing the body’s responses.
Immune: Defends the body against infections and cancer.
Integumentary: Protects against mechanical injury, infection, excessive heart or cold, and drying out.
Muscular: Produces movements, maintains posture, and produces heat.
Skeletal: Supports the body, protects certain internal organs such as the brain and lungs, and provides the framework for muscles to produce movement.
Endocrine: Secretes chem called hormones that regulate body activities such as digestion, metabolism, growth, reproduction, heart rate, and water balance.

7. What animal and plant tissues and organs are equivalent to one another? What body functions do animals have that plants do not? What body functions do plants have that animals do not?

Gas Exchange:
[6th ed.CH 22.1—4, 8—11; 7th ed. CH 22.1—4, 6, 8—11]
1. What is the function of the respiratory system? How are the circulatory and respiratory systems interrelated?

The respiratory system, exchanges gases with the environment to supply blood with O2 and disposes of CO2. The circulatory system and respiratory system are interrelated because the respiratory system provides oxygen to the blood. The circulatory system carries the oxygenated blood throughout the body, keeping cells (and you) alive and functioning well sec. 22.10 and definitions sec. pg 462 and G-23 OR pg 454 sec 22.1

2. What happens to an O2 between the time you breathe it into the lung and it gets used to make ATP in a cell? How does it get from the lung to the cell? How does it get into the cell?
When an animal inhales, a large internal surface that is moist, gets exposed to fresh air. The O2 (Oxygen) diffuses across the cells lining the lungs and into surrounding blood vessels. At the same time, CO2 (Carbon Dioxide) Diffuses out of the blood and into the lungs. And then the animal exhales removing the CO2 from the body.
The O2 that diffused into the blood attaches to the hemoglobin in red blood cells. The oxygenated blood then gets transported by the circulatory system.
then body cells take the O2 from the blood and give CO2 to the blood. Through a process called cellular respiration.
(Section 22.1 pg. 454)
3.What is a respiratory surface? The part of the animal where gases are exchanged with the environment.
What kinds do an EARTHWORM, an INSECT, a FISH, and a MAMMAL have?

The earthworm uses the whole body surface for respiration. Insects have an large system of branching internal tubes called a tracheal system, with the respiratory surface found at the tips, and exchange gases directly with cells without assistance of the circulatory system. Fish have outfoldings of the body surface specialized for gas exchange called gills. Mammals have lungs which are internal sacs lined with moist epithelium, the surface of the lungs branch extensively, forming a large respiratory surface. (section 22.2; pg. 454-455)
What is different about obtaining oxygen from the environment for aquatic and terrestrial animals?
There are two advantages to exchanging gases by breathing air. 1. air has a much higher concentration of oxygen. 2. air is much lighter, and therefore requires less energy to ventilate the respiratory surface.
There is one main disadvantage: the loss of water to the air by evaporation.

4. What is ventilation? What different types are used by different kinds of animals?
Ventilation is a mechanism that provides contact between an animals respiratory surface and the air or water to which it is exposed. There are 4 different types of ventilation;
-earthworms use their outer skin as it’s respiratory surface
-insects use the tracheal system which consists of tubes that extend throughout the body.
-fish use gills which are an extension of the body surface that function in gas exchange with their surrounding water.
-mammals use lungs which are internal thin walled sacs
pg 455 and 456section 22.2and 22.3

5. What is hemoglobin (structure & function)? How many oxygen molecules can it carry? Where is it found?
Hemoglobin is an iron-containing protein that is found in red blood cells; it reversibly binds O2 and transports it to body tissues. It can carry about 4 molecules of oxygen. (It can be found in red blood cells but also through out the body as well) sec 22.11 page 462


[6th & 7th eds Chapter 23 Sections 1—3, 7, 10—12]
  1. What is the function of the circulatory system? Transporting water, nutrients, gasses, and wastes around the body. What are the major component structures of the circulatory system? Heart- muscle that pumps, blood-circulatory fluid, tubes and vessels- carry fluid.
  2. What is different about closed and open circulatory systems? Open system- there is no difference between the blood and the interstitial fluid. Only one body fluid. Open ended vessels. Closed- the blood is in vessels which keep it separate. Where do we find blood versus hemolymph? Blood-in vessels closed system. Hemolymph- open system. Where do we find interstitial fluid and lymph?Closed system. Lymph- in the vessel.the lymph system Interstitial fluid- outside around vessel. Any space in the body.
  3. What type of circulatory system do INSECTS, EARTHWORMS, FISH, and MAMMALS have? What structures are present in each? INSECTS- open. Only hemolymph, muscle around vessel that pumps. EARTHWORMS- closed. Heart like structure, has blood, the inside is segmented like outside. FISH- closed system. 2 chambered heart, single circuit –blood goes through one loop, 1st goes to atrium then the ventricle. Has valves to prevent backflow. Gill=gas exchange. MAMMALS- 4 chambered heart, left side and right side, right atrium and ventricle-sends to lung to get oxygen then to the left side of the heart. 2 circuit system, fish have lower blood pressure than mammals. Both mammals and fish have capillaries.
  4. For fish, amphibians and mammals, know the number of chambers in the heart, the circuit in the body that blood takes, and where it is oxygenated vs. deoxygenated in the circuit. FISH- 2 chambered heart. The atrium receives blood from the veins, the ventricle pumps blood to the gills. High oxygen leaving the gills. AMPHIBIANS- 3 chambered heart- the right atrium receives blood returning from capillary beds, then the ventricle pumps blood to the skin and lungs for gas exchange. Then returns to left atrium but is somewhat mixed from the other atrium. MAMMAL- 4 chambers, the right ventricle pumps poor oxygen blood to the lungs, it goes over the lungs and gets oxygen and then goes to the left atrium, then to the left ventricle where it goes through the aorta out to the body, low oxygen blood returns to the right atrium and then flows into the right ventricle ending the circuit.
  5. For mammals, know the structures of the cardiovascular system in more detail, including structure of the heart and structures in blood circuit.
  6. What is found in vertebrate blood? Cells, plasma- water, ions, proteins, hormones, nutrients, gasses. What are the functions of red blood cells (erythrocytes), carries oxygen and carbon dioxide, has hemoglobin. white blood cells (leukocytes), immune system and platelets parts of a cell, makes a clot, has fibren fibers and platelets to make clots.
  7. How do arteries, veins, and capillaries differ from one another in structure and function? ARTERIES- more force, very thick layer of muscle, carry blood away from the heart to body. VEINS- return blood to the heart, thin layer of muscle, has valves to prevent backflow. CAPILARIES- convey blood between arteries and veins within each tissue.
  8. How do molecules move between the cells and the capillaries? The capillaries are very thin, as little as one cell thick, so they can exchange with tissue.. any substance that is higher concentration with will go out of the capillary. Blood pressure helps some move out. Also diffusion

Water and Salt Balance:
[6th & 7th eds: Chapter 25 Sections 4—7]
Osmoregulation is the method by which organisms regulate solute concentrating and balance the gain and loss of water
Excretion is the disposal of nitrogen-containing metabolic wastes2. What is OSMOSIS? Which way does water move (into or out of the cell) if the environment is hypotonic or hypertonic to the cell? [Review CH 5.4—5]Osmosis is the diffusion of water across a selectively permeable membrane.
Water moves into the cell if the environment is hypotonic
Water moves out of the cell if the environment is hypertonic3. How does the type of habitat an animal lives in determine what its osmoregulatory problems are? What do fish in freshwater and saltwater have to do differently? Hint: Do they both drink water?The type of habitat an animal lives in determines its osmoregulatory problems by the amount of water the animal needs.
An aquatic isotonic habitat has the same solutes in body cells as in environment, many marine invertebrates i.e. squids, sea stars they do not undergo a net gain or loss of water.
Aquatic hypertonic (saltwater fish) habitat has less solutes in body cells as in environment, loses water by osmosis across its body surface,it gains salt by diffusion and from the food it eats. It takes in large amounts of seawater by drinking and it balances solutes by pumping out excess salt through the gills. These are marine vertebrates and some invertebrates i.e. tuna.
Aquatic hypotonic habitat has much higher solutes in body cells as in environment, gains water by osmosis across its body surface, especially its gills. It loses salt by diffusion to its more dilute environment. These fish do not drink water, food helps supply additional ions. These are freshwater invertebrates and vertebrates i.e. trout
Terrestrial habitat must balance water loss to the environment vs. water used to void wastes. Most have an outer skin formed of multiple layers of dead water resistant cells which minimize surface water loss. Maintain water balance by drinking and eating moist foods and by producing water metabolically through cellular respiration. 4. Where do nitrogenous wastes come from? What are the properties of ammonia, urea, and uric acid, in terms of their solubility in water, toxicity, and the amount of work needed to synthesize them? Which kinds of animals living in which habitat types use each type and why?Nitrogenous waste comes from breakdown of amino acids and nitrogenous bases. Properties of ammonia is that it is highly toxic and cannot be stored but it is highly soluble, ammonia is a waste by-product of most aquatic animals, so if an animal is surrounded by water ammonia readily diffuses out of its cells and body so it takes the least amount of work.
Urea is the combination of ammonia and carbon dioxide and has a low toxicity, is mainly produce by mammals and adult amphibians, turtles, sharks and bony fishes, it is highly soluble in water it can be stored safely in high concentration and disposed of with little water loss. Takes energy to synthesize. Can be aquatic or some terrestrial animals like toads. Produced in the liver.
Uric acid (insects, land snails, reptiles, and birds) terrestrial, takes lots of energy to synthesize, is nontoxic, and is insoluble in water so water is not used to dilute it. Excreted as a paste very low water needed.
The general idea is water conservation and little energy.
5. What are the major structures of the osmoregulatory and/or excretory systems of EARTHWORMS, INSECTS and VERTEBRATES? Where do the nitrogenous wastes pass out of the body in each of these kinds of animals?
Earthworms- excretory system is metanephridium open internally to coelom, waste pass out of the nephridiopores
Insects- malpighian tubules-coelom-hindgut and dry wastes (including uric acid) pass out of the rectum
Vertebrates-intestines, hepatic portal vein, liver, kidneys6. What are filtration, reabsorption, secretion, and excretion? What kind of molecules are moved from where to where in each?Filtration-collect solutes from blood-H2O, other small molecules from the Bowman’s capsule to the kidney tubule
Reabsorption-water, glucose and other solutes are returned to blood-other ions and amino acids from the filtrate and returned to the blood
Secretion-substances from blood move into tubule (nephron)- H+ and drugs and toxic substances from the blood to the filtrate
Excretion-urine containing remaining solutes are passed from the body-from the kidneys to the outside via the ureter, urinary bladder, and urethra.7. What are the parts of the kidney? What are the parts of the nephron and in what order does filtrate flow through them? In which part of the nephron do filtration, reabsorbtion and secretion occur?Bowman’s capsule, renal artery, renal vein, renal cortex, renal medulla, Nephron tubule, collecting duct.
Nephron parts are the Bowman’s capsule, nephron tubule, and collecting duct in that order.
Filtration occurs in the cortex in the Bowman’s capsule, and reabsorption and secretion occurs in the nephron tubule.

Coordination and Control

1. What is homeostasis? What roles do the nervous and endocrine systems play in maintaining it? Homeostasis is how our bodies capably maintain a constant level in our internal environment, with only small changes occurring, despite big changes that happen outside the body in the external environment. Endocrine system is responsible for secreting the hormones that maintain our internal state and keep it steady. The nervous system plays the role of directing the bodies responses to stimuli and integrating information.2. What is a hormone? Where are they made and where do they go? How do they get there? What do they do when they get there? A hormone is a chemical message that is carried in the blood. They are made and secreted by endocrine glands. Carried to other parts of the body to communicate messages. They reach all cells of the body.3. What is a neurotransmitter? What does it do at a synapse? A neurotransmitter is a chemical that carries information from one nerve cell to another or from a nerve cell to another kind of cell that will react. The neurotransmitter rushes over the synapse and is released, then binds to the receptor.4. How is homeostasis with respect to oxygen levels in the blood maintained in mammals? What organ systems are involved? What are triggers for increased respiratory rate? Breathing control center responds to the pH of blood. The organs involved are the brain and heart and the organ systems involved are the nervous system, circulatory system, muscular system and respiratory system. A trigger for increased respiratory rate would be rigorous exercise.5. What is a negative feedback loop and what is their role in homeostasis? A response that performs to an action in the opposite direction of what is already in process. This helps maintain and control stability in the internal environment of the body.6. How is the number of Red Blood Cells in the blood regulated? Why is this needed? Regulated by a negative feed back mechanism that is sensitive to the amount of oxygen that reaches the tissues via the blood. If tissues are not receiving enough oxygen the kidneys produce a hormone called erythropoietin, which stimulates the bone marrow to produce more blood cells. This is needed so that the body does not become anemic and susceptible to other complications.7. How are body temperature and blood glucose in mammals regulated? Homeostasis and negative feed back. If body temperature rises, the brain activates cooling mechanisms and sweat glands secrete sweat to cool down the body. Visa versa if the temperature of the body drops; brain sends a signal and skeletal muscles contract to create the shivering effect, which generates heat. In glucose homeostasis, if blood glucose rises beta cells in pancreas release insulin into the blood and the liver and body cells take up the glucose. Blood glucose level declines and stimulus for insulin fades.8. What things contribute to blood pressure? How do the kidney and nervous system work together to regulate blood pressure?