Download Review Sheet for Living Environment Final 1) Name and explain the

Review Sheet for Living Environment Final
1) Name and explain the steps of the scientific method.
1) Observation: observations of the world around us lead scientists to questions that have to be
answered
2) Problem/Questions: Develop a question/problem based on observations that can be solved by
conducting a test
3) Research: Research topic of interest to determine what has been discovered to date. Scientists
want to build knowledge upon existing info
4) Hypothesis: Predict possible answer to question or problem base on research; an educated guess
about the relationship b/w the independent (changing) and dependent (measured) variable
5) Experiment: Develop and follow a procedure, include a detailed materials' list. The outcome must
be measurable (quantifiable) Must need a control group known as a no treatment group or experiments
selected group
6)
Organize data by tables, analyze using graphs
7)
Collect and analyze results: include table, graphs and photographs; modify procedure if needed
8)
Repeat to confirm the results
Validity of Experiment:
a)
control group
b)
Repeat and get same data
c)
increase sample size
d)
limit only to one independent variable
9)
Conclusion: Include a statement that accepts or rejects the hypothesis; make recommendation for
further study and possible changes in procedure
10) Communicate Results: Be prepared to present the project to an audience. Expect questions from
the audience
2) Compare and contrast Dependent vs. independent variables.
Independent variable (manipulated variable) is the variable being tested (intentionally varied by the
experimenter) whereas the dependent variables are the variables that are affected/ the result of the
independent variable.
3) Identify the taxonomic groups- which are the most general? The most specific?
In order from least to most specific:
Domain, kingdom, phylum, chess, order, family, genus, species
4) Know the characteristics of the major kingdoms and domains.
Domains:
a) Archea (Only kingdom is archaebacteria)
Prokaryotic
Unicellular
Live in extreme environments
b) Bacteria (Only kingdom is eubacteria)
Unicellular
Prokaryotic
“Common” bacteria
c) Eukarya (includes all of the eukaryotic kingdoms: protista, fungi, plantae, animalia)
The Kingdoms of Eukarya
a)
Protista
Unicellular or colonial
Many have cell walls
Can be plant-like, animal-like or fungus-like
b)
Fungi
Cell walls made of chitin
Multicellular
External heterotrophs
Decomposers
c)
Plantae
Cell walls of cellulose
Autotrophic
Multicellular
d)
Animalia
Multicellular
No cell walls
Internal heterotrophs
5. Name the parts of an atom.
Protons: positively charged in center
Neutrons: uncharged in center
Electrons: negatively charged in orbit around nucleus
6. Explain how bonds are formed.
Ionic bonds are formed when one atom gives electrons away to another. This gives that atom a negative
charge and the other a positive one, attracting them together. Covalent bonds are formed when
electrons are shared equally or unequally. The electrons orbit around both atoms. Hydrogen bonds are
formed by the attractive intermolecular force that exists between two partial electric charges of
opposite polarity and almost always involves hydrogen.
7. What is an ion? Isotope?
An ion is a charged atom or molecule; an atom or molecule that has either an excess of electrons or has
lost electrons. Isotopes are atoms of the same elements but with different masses due to a difference in
the number of neutrons.
8. Compare and contrast the three types of bonds.
An ionic bond is a type of chemical bond formed through an electrostatic attraction between two
oppositely charged ions. A covalent bond is a form of chemical bonding that is characterized by the
sharing of pairs of electrons between atoms. A hydrogen bond is the attractive interaction of a hydrogen
atom with an electronegative atom.
In order from weakest to strongest: hydrogen bond, ionic bond, covalent bond
9. Compare and Contrast organic and inorganic materials
All organic compounds contain carbon. They are all made by living things. They usually also have
hydrogen and or oxygen.
10. Name the organic compounds, their building blocks and their functions (and examples)
Carbohydrates are made by monosaccharides (glucose, fructose) and disaccharides (sucrose). They are
used for energy, production, storage, and structure. Lipids are used for waterproofing (waxes), the cell
membrane (phospholipids), energy storage (fats), and hormones (steroids).
They are made up of three fatty acids attached to a glycerol (besides phospholipids which contain two
fatty acids with a phosphate head and a glycerol, giving them a hydrophobic and hydrophilic side).
Nucleic acids are made of nucleotides (ribose/deoxyribose, phosphate group and nitrogenous bases).
DNA has deoxyribose, is stable, and has the bases adenine, guanine, thymine and cytosine; it determines
genetic information. RNA has ribose, is unstable, has uracil instead of thymine, can be used as an
enzyme. Nucleic acids are used as genetic materials and short-term energy carrier molecules in the cell
as well as intracellular messengers. Proteins are made of amino acids. Proteins carry out life functions
such as enzymes, antibodies, messages, structure and transport. Amino acids have a central carbon
attached to an amino group, a carboxyl group, a hydrogen, and a variable group.
11. Compare and contrast dehydration synthesis and hydrolysis.
Dehydration synthesis is the removal of a hydrogen atom from one molecule and an OH from another,
forcing them to form one molecule as well as forming a molecule of water. Hydrolysis is the addition a
water molecule to a molecule, forcing it to break into two separate molecules.
a. Why are they are considered to be complimentary reactions.
The products of dehydration synthesis are the reactants of hydrolysis, while the reactants of
dehydration synthesis are the products of hydrolysis.
12. Why are enzymes said to be specific? What determines their specificity?
Enzymes are specific because they only bind to specific active sites. The 3-D shape of the enzyme
determines it specificity and its shape is determine by it order of amino acids which is determined by it
DNA sequence.
13. Name the conditions that effect enzyme specificity.
1)
pH
2)
Temperature
3)
Substrate and Enzyme Concentration
14. Explain how DNA is able to control the activities of a cell.
DNA is the brains of the cell and tells it what to do. There is no actual "control". The arrangement of
proteins on the gene determines how a cell is structured and what it does.
15. Name and explain the life functions
The life functions are reproduction, growth and development, the need for materials and energy,
response to the external environment, homeostasis, change over time, formation of cells. Reproduction
is the creation of a new organism nd there are two types. Asexual reproduction is when one parent
produces one offspring that is genetically identical to it. Sexual reproduction is when two parents
produce an offspring and is a combination of the genetic material of both of its parents. It is the only life
function that is not necessary for the survival of an individual. Growth and developments are the life
functions by which an organism increases in size. In unicellular organism, growth is simply an increase in
cell size. In multicellular organisms, growth is an increase in the number of cells. In multicellular
organisms growth is accompanied by cellular specialization where certain cells or groups of cell take on
a specific shape and function. Growth is not unlimited. The need for material and energy includes five
steps. Metabolism is the combination of all the chemical reaction that occur in the body. Synthesis is the
process by which organisms combine simple substances chemically into more complex substance.
Assimilation is the process by which substances are incorporated into living things. Nutrition is the
process by which an organism takes in materials from the external environment and changes then into
forms they can use, nutrients. Response to the environment is the life function of regulation where an
organism responds to a stimulus or a signal that may be external or internal. In unicellular organism this
is done by the cell membrane and nucleus. In multicellular organisms the endocrine and nervous system
are responsible for regulation. Homeostasis is how organisms maintain a stable internal environment.
Homeostasis is accomplished in transport, excretion and gas exchange. Transport is the life function
responsible for the movement of substances around a cell or around a body. In unicellular organisms
transport is accomplished by the moving of the intracellular fluid. In some multicellular organisms this is
accomplished by the circulatory system. Excretion is the life function responsible for the removal of
metabolic wastes from the body. Gas exchange is the life function responsible for the exchange of
oxygen and carbon dioxide between an organism and the environment. In unicellular organisms and
simple animals, gas exchange occurs directly though the cell membrane. In plants, gas exchange occurs
through openings in the leaves called stomates. In complex organisms this is accomplished by the
respiratory system. Change over time is the life function of evolution or the ability of a group of
organisms to change over time. It occurs in a population. Evolution is possible because of genetic
material such as DNA. All organisms are made of cells.
16. Name Parts of Cell theory
All living things made of cells.
Cells come from cells.
Cells are smallest living things.
17. Name and functions of all cell organelles
Plasma membrane: Selectively permeable, determines what enters and leaves the cell
Cytoplasm: Fluid that fills the inside of the cell.
Ribosomes: Don’t contain membrane and are made of RNA and proteins, site of protein production.
Nucleus: Surrounded by the nuclear envelope, contains the DNA.
Nucleolus: The inside of the nucleus; it is the location where ribosomes are made.
Endoplasmic Reticulum: Transport system within the cell. Many ribosomes are on its walls.
Golgi complex: Where things are modified and sorted for storage or transport out of the cell.
Vacuole: Large fluid filled sac with a membrane. It is needed for storage. In plants, it helps hold the body
up.
Lysosome: Sac surrounded by a membrane containing enzymes. Digestion in unicellular organisms,
destroys invaders, and breaks down old cells.
Centrioles: Are only found in animals and are responsible for proper cell division.
Mitochondria: Have a double membrane and its own DNA. This is the location of aerobic respiration.
Chloroplast: Double membrane, has its own DNA, is needed for photosynthesis.
Cell Wall: Present in plants and algae, provides support and protection.
a. How do these organelles work together to carry out homeostasis?
They carry out all of the life functions. A vacuole fuses with a lysosome, which digests the contents of
the vacuole. The nucleus creates DNA, which is copied by RNA which gives that info to the ribosomes in
the endoplasmic reticulum which produce proteins with that info. They are then often sent to the Golgi
complex.
18. List the levels of organization of living things from smallest to largest
cell → tissue → organ → organ system → organism → species → population → community → ecosystem
→ biosphere
19. Compare and Contrast Autotrophic and Heterotrophic Nutrition
20. What is ATP? How does it store energy?
ATP is a short-term energy carrier. ATP is formed by the bonding of a phosphate group with ADP. The
energy is stored in the third phosphate, the last phosphate that joins with ADP to form ATP.
21. Compare and contrast photosynthesis and cellular respiration.
Photosynthesis is the conversion of light energy in the form of radiation into chemical energy in the
form of glucose. Respiration is the process by which energy stored in the bonds of glucose is released in
the form of ATP.
a. Identify where these processes occur
Photosynthesis occurs in the chloroplast. Respiration occurs in the cytoplasm as well as the
mitochondria.
b. What are the raw materials
Photosynthesis: 6 CO2 +6 H2O + Sunlight
Cellular Respiration: C6H12O6 + 6 O2
c. What are the final products
Photosynthesis: C6H12O6 + 6 O2
Cellular Respiration: 6 CO2 + 6 H2O + 36 ATP
d. Why they are considered to be complimentary reactions.
The products of photosynthesis are the reactants of cellular respiration, while the reactants of
photosynthesis are the products of cellular respiration.
22. Explain the steps of the light reactions and the dark reactions
a. Identify where these processes occur
Light reactions occur in the thylakoid membranes of the chloroplasts. Dark reactions occur in the stroma
of chloroplasts.
b. What are the raw materials
Light reactions: Light Energy + 2 H2O
Dark reactions: 6 RuBP + 6 CO2
c. What are the final products
Light reactions: NADPH + ATP
Dark reactions: C6H12O6
23. Compare and contrast aerobic and anaerobic respiration
Anaerobic respiration is a form of respiration that does not require oxygen. It occurs in the cytoplasm
and in all prokaryotic organisms as well as yeast. Aerobic respiration is a form of respiration that can
only occur in the presence of oxygen. It occurs in the mitochondria and in eukaryotic organisms. In both
however, glycolysis occurs where C6H12O6 + 2 ATP + 2 G3P form 2 pyruvic acid + 2 ATP + 2 NADH.
24. What is the purpose of fermentation? What are the end products?
Fermentation is necessary for the regeneration of NAD+ for glycolysis. The end products of alcoholic
fermentation are ethyl alcohol, CO2 and NAD+. The end products of lactic acid fermentation are lactic
acid and NAD+.
25. Explain the steps of cellular respiration
a. Identify where these processes occur
Glycolysis occurs in the cytoplasm. The Krebs cycle occurs in the matrix of the mitochondria. The
electron transport system occurs in the inner membrane of the mitochondria.
b. What are the raw materials
Krebs cycle: 2 Pyruvic acid
Electron Transport System: 2 FADH2 + 10 NADH
c. What are the final products
Krebs cycle: 2 ATP + 2 FADH2 + 8 NADH + 6 CO2
Electron Transport System: 32 ATP + 6 H2O
26. Location and function of stomata and guard cells.
Scattered through the lower epidermis are small openings called stomata. It is through these holes that
CO2 enters the lead and oxygen and water vapor exit. Each stomate is surrounded by a pair of guard
cells. When they swell the stomates open and when they shrink the stomates close. Plants respond to
change in temperature and humidity by opening or closing their stomates.
27. Identify 4 Steps of Heterotrophic Nutrition
Ingestion (taking in materials)
Digestion (breakdown of complex molecules)
Absorption (nutrients are incorporated)
Egestion (removal of undigested materials)
28. Compare and contrast mechanical and chemical digestion.
Chemical digestion is done by enzymes making a conformational change to something’s shape.
Mechanical digestion is a physical mashing that often makes it easier for enzymes to attach (increases
surface area).
29. Know the digestive processes and accessory organs (if applicable) in hydra, grasshopper and
earthworm.
Hydra:
The tentacles push food into the gastrovasuclar cavity. The cells of the endoderm release enzymes into
the cavity that break down the food that then diffuses into the cells where further digestion occurs.
Grasshopper:
Food goes from the mouth (mechanical digestion) through the esophagus to the crop (temporary
storage), into the gizzard (mechanical digestion) into the stomach (chemical digestion and absorption).
Earthworm:
Into the mouth, through the pharynx and esophagus, into the crop (storage), into the gizzard, into the
intestine (chemical digestion and absorption).
30. Organs and stages of human digestion. – What is digested where? By what enzyme?
In the mouth, swallowing and break large polysaccharide into smaller ones occurs. Saliva provides
lubrication of food. Food travels into the esophagus and then into the stomach where mechanical
digestion and the breakdown of proteins by pepsin occurs.
Food in the form of chyme travels into the small intestine (Break down of starch into maltose by
amylase. Polypeptides break down into dipeptides by trypsin and chymotrypsin. Break down of lipids by
lipase which is helped by bile, the emulsifier. Those come from the pancreatic juice. Bile is from the
liver. The intestinal juice itself has carboxypeptidase and aminopeptidase that complete protein
digestion. Maltase and others break disaccharides into monosaccharides.) After absorption out of the
small intestine, food goes to the large intestine and out the anus.
31. Explain how gas exchange, excretion and nervous regulation are accomplished in the hydra,
earthworm and grasshopper. (be sure to identify if these structures are dorsal or ventral)
In the hydra gas exchange occurs across the cell membrane of the ectoderm and endoderm because
they are in constant contact with their environments. In the earthworm, gas exchange occurs across the
skin which is the respiratory surface and into the capillaries that lay behind it. In the grasshopper, gas
exchange occurs across the tracheoles which penetrates the cells and serve as a site of diffusion, But
before reaching the tracheoles. Air must first travel through the spiracles located in the thorax and
abdomen and through the trachea and then in to the tracheal tubules.
Excretion in the hydra occurs via diffusion. In the earthworm, excretion occurs in the nephridia, the
filtering unit, where wastes enter the nephridia through the nephrostome and then travel into the long
convoluted tubule where there are blood vessels. Metabolic wastes are also delivered here. This also
serves as the site of diffusion of necessary material. At the end of reabsorption only waste materials
remain and these are collected in the long convoluted tubule and are emptied into the environment via
the nephridiopore in the form of urine. In the grasshopper, wastes from the blood enter the excretory
organ known as the Malphigian tubules via diffusion. These tubules are in direct contact with the blood
because of the open circulatory system. Body fluids are drawn into the tubules by osmosis due to the
large potassium concentration inside of the tubule. Body fluids re-enter the body free of nitrogenous
wastes, while the wastes are emptied into the intestines where water and nutrients are reabsorbed and
wastes is excreted in the form of uric acid.
Hydra has no centralized nervous system. Nervous cells run between the layers of cells that make up the
hydra. When an impulse is received by one part of the hydra, all of the cells of the hydra receive the
impulse and there is coordinated response by the organism. The earthworm contains and organized
nervous system, a central and peripheral nervous system. The central nervous system is made of the
brain and a pair of ventral nerve cords. The nerve cords enlarge into ganglia in each segment. The
ganglia are a bunch of cell bodies and interneurons that relay and coordinate nerve impulse. The brain is
two fused ganglia. The peripheral nervous system is made of nerves that branch off the central nervous
system and connect to all parts of the body. The peripheral nervous system contains the sensory and
motor neurons. The grasshopper is made of the brain in the head region and two ventral nerve cords
that run off it with ganglia. Nerves branch out from the ganglia making up the peripheral nervous system
and connecting to all parts of the body. The sense organs are more highly developed in the grasshopper
than the earthworm.
32. Trace the pathway of air in the respiratory system.
nose → nasal cavity → nasal passages→ pharynx→ trachea → bronchi → bronchiole tubules → alveoli
33. Why is it important to breathe through the nose?
It warms and filters the air that is breathed.
34. Name and explain 2 disorders of the respiratory system.
Asthma is characterized by the constriction, inflammation, and excessive lining of mucus of the airways
often in response to one or more triggers cause by allergens. Bronchitis is an inflammation of the
membranes lining the bronchi nd the excessive production of mucus. Symptoms of bronchitis include
coughing up extra mucus, difficulty breathing and a runny nose. Emphysema is characterized by the
destruction of structure supporting the alveoli and the capillaries feeding the alveoli. The small airways
collapse during exhalation blocking the airflow and trapping air in the lungs. Pneumonia is an
inflammation of the lungs caused by a bacterial, viral or fungal infection. The type of infection
determines the fatality.
35. Name and identify the functions of the parts of the nephron.
A nephron is the functional unit of the kidneys. Part of the nephron is found in the cortex and part is
found in the medulla. Also found in the cortex is a group of capillaries that form a tight-ball called the
glomerulus. The glomerulus is surrounded by Bowman’s capsules, a double-walled, cup shaped structure
which is the beginning of the nephron.
36. Explain how urine formation occurs in the kidney.
Urine is formed in the pelvis of the kidney as a result of mixing urea with water and other materials.
37. Where is water reabsorbed? Nutrients? Ions?
Nutrients, water and ions are reabsorbed in the distal convoluted tubule.
38. What does ADH do in the kidney?
Dehydration stimulates the production of ADH which increases the permeability of the distal tubule and
collecting duct resulting in more water being retained. Because more water is retained there is an
increase in the concentration of water in the blood. This halts the production of ADH which decreases
the permeability of the distal tubule and collecting duct resulting in less water being retained.
39. Name and identify the functions of the parts of the neuron.
The cell body of a neuron contains the nucleus and all organelles. This is where all life functions are
carried out. It acts as the integrating center of the neuron and determines if an impulse will be initiated.
40. Compare and contrast the central and peripheral nervous system.
The central nervous system is composed of the brain and the spinal cord. It is made of interneurons,
synaptic bulbs of sensory neurons and cell bodies of motor neurons. The central nervous system
controls most of the activities of the body and has three levels of protection: bone (skull and spinal
column), meninges (triple layer of connective tissue and cerebrospinal fluid (cushions the brain and
spinal cord). The peripheral nervous system is composed of all the neurons which branch out from the
brain and the spinal cord. It is made of sensory neurons and motor neurons. The peripheral nervous
system is made up of the somatic and autonomic nervous system. The somatic nervous system controls
voluntary movement and is made of neurons that connects the central nervous system to the sense
organs. The autonomic nervous system controls involuntary movement. It is made of neurons that
connect the central nervous system to the internal organs of the body and controls heart rate,
breathing, blood flow, digestion and hormone secretion from glands. The autonomic nervous system is
divided into the sympathetic and parasympathetic nervous system. The sympathetic nervous system is
responsible for flight or fight response. The parasympathetic nervous system is responsible for body
activities and returns the body to normal after the flight or fight response.
41. Identify the functions of the parts of the brain.
The brain is composed of the hindbrain, midbrain and the forebrain. The hindbrain is composed of the
medulla, pons and cerebellum. The medulla controls breathing, heart rate, blood pressure and
swallowing. The pons controls the stages of sleep, rate and patterns of breathing. The cerebellum
controls the coordination of body movements. The midbrain is composed of the auditory relay center,
reflex of the eye and the reticular formation. The reticular formation is the processing center for the
senses. It filters sensory inputs before they reach the conscious part of the brain. It controls what you
process. The forebrain, also known as the cerebrum, is composed of the thalamus, limbic system and
the cerebral cortex. The thalamus carries sensory information to the cerebral cortex or the limbic
system. The limbic system controls the basic and primitive emotions, drives and behavior. The limbic
system is composed of the hypothalamus, the amygdala and the hippocampus. The hypothalamus is the
major coordinating center of the brain. The amygdala is the ancient part of the brain that controls the
primitive emotions and emotion recognition. The hippocampus controls emotions but is also needed for
the formation of long-term memory. The cerebral cortex is divided into the left and right hemisphere.
They are connected by the corpus callosum. The cerebral cortex contains folds and convolutions which
increase surface area. It is gray in appearance due to a large volume of cell bodies. It is the largest part
of the brain (2/3) and is divided in half into the right and left hemisphere (right art, left math). It controls
sensory, motor and associative responses. It receives and interprets sense impulses and starts impulses
responsible for voluntary movement and the position of limbs. It is responsible for memory learning and
thought.
42. Identify the functions of the parts of the eye and the ear.
The wall of the eye has three layers. The sclera is the white of the eye and gives it its shape. The cornea
is the transparent structure that bulges out and contains no blood vessels. It is needed to focus light.
The limbus is where the cornea meets the sclera. The middle of the eye contains the iris, the colored
part of the eye, and many blood vessels. The iris regulates the amount of light that enters by
determining the size of the pupil. The pupil lies on the lens which helps to focus light on the back of the
eye. Most of the eye is filled with a clear gel called the vitreous humor. Light projects through the pupil
and lends to the back of the eye. The inside lining of the eye is converted by special light-sensing cells
which together form the retina. The retina converts light into electrical impulses. The macula is a
sensitive area within the retina that gives central vision. It is located in the center of the retina and
contains the fovea. Behind the eye, the optic nerve carries these impulses to the brain. Eye color is
created by the amount and type of pigment in the iris. The retina contains two types of photoreceptors
which are rods and cones. There are more rods than cones which are more sensitive than the cones but
are more sensitive to color. The cones provide the eye’s sensitivity and they are more concentrated in
the yellow central spot known as the macula. In the center of that region is the fovea centralis. A 0.3mm
diameter rod-free area with very, thin densely packed cones. There are three different types of cones:
red, green and blue which provide the eye’s color sensitivity. In the photo-excitation process the, the
rhodopsin protein absorbs light and is excited to a high electronic state. Upon the photo-excitation
process, the retinal part of rhodopsin undergoes a conformational change. Rhodopsin dissociated from
the opsin protein. This change in geometry initiates a series of events that eventually causes electrical
impulses to be sent to the brain along the optic nerve.
The ear translates vibrations in the air into vibrations in fluids and finally into an impulse. There are
three regions in the ear: the external ear, middle ear and inner ear. The external ear contains the pinna
and external auditory canal which collects sound waves and channels them to the middle ear. The
middle ear contains the eardrum and auditory ossicles. The inner ear contains the nerve fibers that will
initiate the sensory impulse. Sound enters the outer ear and causes the tympanic membrane (eardrum)
to vibrate. This causes the auditory ossicles: the malleolus, the incus and the stapes to vibrate. These
small bones pass the vibration down the air-filled Eustachian (auditory) tube to the membrane at the
entrance of the inner ear. The inner ear has three parts: the vestibule, the semi-circular canals and the
coiled cochlea. The vestibule contains the fluid filled sacs that are associated with equilibrium. The three
semi-circular canals are also filled and lined with hair whose movements help determine the rate and
direction of movement. The coiled cochlea connected to the stapes by the oval window. The amplified
vibrations from the auditory ossicles are transferred to the fluid within the cochlea through the oval
window. This causes the movement in the hairs lining the cochlea which in turn stimulates the sensory
receptors.
43. Name and identify the sense receptors.
Thermoreceptors are receptors for heat. Mechanoreceptors are receptors for touch, pressure and
vibration (sound and balance). Photoreceptors are receptors for light. Chemoreceptors are receptors for
taste and odor. Pain receptors are receptors for pain.
44. Compare and contrast specific and non-specific defenses.
Nonspecific defenses are the responses of immunity that fights of all pathogen. This form of immunity
includes the 1st line of defense and the 2nd line of defense. Specific defenses respond and fight against
only one pathogen. An example would be the attack of Killer T-cells against one pathogen which they
are able to find by its antigen on its surface. Once the Killer-T cells has been activated by the Helper Tcells it fights against that specific pathogen.
45. Explain how the inflammatory response works.
1)
Pathogen enters the body tissues and causes damage
2) Damaged cells and mast cells release protein messengers called histamine which attach to adjacent
capillaries and cause them to leak allowing white blood cells and clotting factors to enter the site of
infection.
3) Macrophages exit the blood stream at the site of infection using amoeboid movements to squeeze
out.
4) Macrophages come to the site of infection and eat damages cells, all foreign particles and some
healthy cells.
5)
Pathogen in the vacuoles are digested using the digestive enzymes of the lysosomes
6)
The antigen on the pathogen is displayed on the membrane of the macrophages
7)
Once the area has been cleaned the macrophages die forming pus or mucus at the site of infection.
46. Compare and contrast cell mediated and hummoral immunity.
The hummoral immune response is the aspect of immunity that is mediated by secreted antibodies
produced by B lymphocytes or B-cells. Secreted antibodies bind to antigens on the surfaces of invading
microbes which flags them for destruction. Hummoral immunity involves substances found in the body
fluids and is activated once the pathogen enters the blood stream.
1)
Antigen from the pathogen is displayed on the membrane of macrophages.
2) Antigen attaches to the Helper T-cell receptor, activating it against the pathogen (usually occurs
during inflammatory response).
3) Immature B-cell encounters a pathogen, ingests it by phagocytosis and then digests it using the
lysosome.
4) The antigen no displayed on the membrane of the B-cell attaches to a receptor on an activated
Helper T-cell
5) Once the Helper T-cell determines that the antigen is foreign tit releases cytokine a protein that
attaches to and activates the B-cell
6) The activate B-cells divide into plasma cells which produces the antibodies and memory cells
which will remain in the blood long after the infection has ended.
7) The antibodies released from Plasma B-cells travel through the blood and attach to the antigens on
the surface of the pathogens
8)
Macrophages ingest and then digest using the lysosome, all molecules surrounded by antibodies
The cell-mediated immune response relies on lymphocytes and not antibodies. It starts when a T-cell
binds to and activated macrophage and then becomes a Helper T-cell, which helps regulate the
production of antibodies by B-cells. Helper T-cells activate Killer T-cells which transfer protein into the
cell membrane of a pathogen causing fluids to leak out of the membrane. This rapid loss of materials
causes the cell to rupture and die.
1) Helper T-cell is activated by binding to the antigen of a pathogen found on the surface of a macro
phage
2)
Killer T-cell recognizes an antigen on the surface of a macrophage
3)
Helper T-cell releases cytokines which activates the Killer T-cell
4) Killer T-cell searches fir infected body cells (those that display part of their antigen on their
membrane surface).
5)
Killer T-cells dock on the surface on an infected cell, bind to the processed antigen on the surface
of infected cells
6) Killer T-cells release inject) digestive enzymes which cause the cell to enter apoptosis (programmed
cell death) or the protein perforin which create holes in the membrane of the infected cell.
7)
Macrophages then come and ingest and further digest those cells attacked by the Killer T-cells
47. Define antigen, antibody, interferon, pathogen
An antigen is any substance on a pathogen that is recognized as foreign. Antibodies are proteins that are
found in the blood and are used to identify and neutralize foreign objects. Antibodies can identify and
bind only to their unique antigen even in the midst of the millions of different molecules that are
present in the blood. Recognition by an antibody tags a substance for attack by macrophages.
Antibodies can also neutralize pathogen by preventing infecting from entering the body cells. An
interferon is a protein released by certain virus-infected cells that increases the resistance of other,
uninfected cells to the viral attack. A pathogen is anything that can cause an illness (e.g. bacteria, fungi,
viruses and toxins).
48. Name and describe the three malfunctions of the immune system.
The three categories are autoimmune diseases, allergies and immunodeficiencies. Autoimmune diseases
are occurs when the immune system attacks the cells of the body andlupus erythematosus, rheumatoid
arthritis, multiple sclerosis, and myasthenia gravis. Allergies are by allergens. Allergens cause the
immune system to have a hypersensitivity reaction because of the release of histamines by IgE.
Histamine causes swelling of mucous membranes, such as in the nose and throat, and congestion.
Immunodeficiencies are caused by HIV in humans.
49. Why is HIV such a deadly pathogen?
HIV actively infects the Helper T and macrophage cells of the body. This results in no immune system
because there are no Helper T-cells to activate the immune response against the virus.
50. Explain how a vaccine works.
A vaccine activates an immune response by the injection of a weaken or dead form of the virus into the
blood stream. This results in an active immunity against the disease so that is the disease where to enter
the body it would be fought at with an even greater power than it was fought during the vaccine
injection.
51. Explain 3 examples of how increased surface area allows the body to function more
efficiently.
Dendrites, villi on the small intestine, the alveoli of the lungs, convolutions of the cerebral cortex, and
the rugae of the stomach are examples of increased surface area.