Biology 2201 Final Exam Review

Unit 1: Cells

Cell Theory:

Cell theory is these four hypotheses:

- All living organisms are composed of one or more cells.- Cells are the basic units of structure and function in all organisms.- All cells are derived from pre-existing cells.- In a multicellular organism, the activity of the entire organism depends on the total activity of its

independent cells.

Abiogenesis: The idea that living organisms can develop spontaneously from lifeless matter. (Abiogenenis is false).

Biogenesis: the idea that living organisms develop only from other living organisms and not from abiotic matter. (Biogenesis is true).

Scientists:

Pasteur: Tried to settle the debate between biogenesis and abiogenesis. He used a swan necked flask, allowing air in, but kept germs out while boiling the broth. He disproved abiogenesis.

Redi: demonstrated that maggots do not appear in meat if flies cannot land on the meat. Scientists began to doubt abiogenesis.

Needham: Boiled meat broth to support spontaneous generation. The jar became cloudy because it was not properly sealed.

Virchow: concluded that calls are the last link in a great chain that forms tissues, organs, systems and individuals. Where cells exist, there must be a pre-existing cell.

Von Lewenhoek: Discovered animal cells, father of the microscope.

Microscopes:

The 3 types of microscopes are:

a. Compound light microscope – these are the simplest and most commonly used microscopes. The can view many but not all cells and have a maximum magnification of about 2000x.

b. Transmission electron microscope – these microscopes use a beam of electrons that pass through the ultra-thin specimen, interacting with it as it passes through. An image is formed through the interaction of the specimen with the electrons. The maximum magnification of a TEM is about 500 000x.

c. Scanning electron microscope - Images surfaces at an atomic level. This microscope provides 3D images. The SEM scans a narrow beam of electrons over the specimen.

Cell Structure:

Animal cell: a form of eukaryotic cell that makes up many tissues in animals.

Plant cell: Eukaryotic cells that make up plants.

What’s the difference?

First of all, plant cells have a cell wall made up of cellulose, which allows the plant cell to maintain a high pressure inside of it without bursting. Animal cells do not have this wall, so if you fill up an animal cell with too much liquid, it will break. Plant cells are also different from animal cells because they use photosynthesis to convert sunlight into food for the plant. Plant cells also have chloroplasts, which contain their own DNA, essentially directing the work of the chloroplasts. Plant cells also contain a large vacuole that takes up much of the space in the cell; it contains waste, nutrients and water which are secreted as necessary. Animal cells have small and numerous vacuoles.

Prokaryotes vs. Eukaryotes:

Eukaryotic cells have a true nucleus, bound by a double membrane. Prokaryotic cells have no nucleus. Eukaryotic DNA is linear, prokaryotic DNA is circular. Eukaryotic DNA is complexed with proteins called ‘histones’ and is organized into chromosomes, prokaryotic cells have no histones associated with it. Eukaryotic cells have more complex rhibosomes. Eukaryotic cells are filled with a variety of organelles, each serving a different purpose. Prokaryotic cells contain no membrane-bound organelles.

Organelles:

Nucleus: Cells largest and most prominent organelle. Stores genetic information that determines how the cell functions.

Nucleolus: Within the nucleus. Produces the chemical compounds used to construct the ribosomes required by the cell.

Ribosomes: Each cell contains thousands. Lack a membrane envelope and are assembled in the nucleus. Produce protein used within the cell.

Rough Endoplasmic reticulum (Rough ER): ER covered with ribosomes. The proteins produced on these rhibosomes are processed and modified with the help of enzymes embedded on the inside of the rough ER.

Smooth ER: Have enzymes embedded on the inner surface for processing macromolecules. Sections of smooth ER pinch of to form vesticles which transport macromoleules to the cellmembrane or Golgi apparatus.

Golgi apparatus: Packages proteins into vesticles.

Lysosomes: Produces enzymes to destroy bacteria.

Vacuole: Stores water and ions.

Flagellum: Tail like structures for cell locomotion.

Mitochondrion: Power house of the cell, produces ATP energy.

Chloroplast: Site of photosynthesis (plant cells only).

Amyloplast: Stores starch in plant cells.

Centriole: Produces spindle fibres for mitosis.

Cytoplasm: Liquid in which all organelles are contained.

Chromosomes: genetic material in nucleus.

Cell Membrane: Semi permeable boundary around cell that contains organelles.

Cell Wall: Plant cells only. Made of cellulose and makes the cell rigid.

Cell membrane:

The fluid mosaic model of a biological membrane includes :

- Phospholipid bilayer- Cholesterol- Glycoproteins- Integral proteins embedded in the phospholipid bilayer of the membrane.- Peripheral proteins attached to the phospholipid surface.

- The hydrophobic and hydrophyllic properties ofphospholipids help to maintain the structure of cell membranes.

o Hydrophobic fatty acid tails repel water and form in the middle layer of the membrane.o Hydrophyllic phosphate heads attract water and form the outer layers of the

membrane.

...Sarah plays with paint!

Functions of membrane proteins:

- Hormone Binding sites- Enzymes- Electron Carriers

- Channels for passive transport- Pumps for active transport

Osmosis: Movement of water from an area of high concentration to an area of low concentration.

- Hypertonic solutions: Contain a high concentration of solute relative to another solution. When a cell is placed in a hypertonic solution, water diffuses out of the cell, causing it to shrivel.

- Hypotonic solutions: Contain a low concentration of solute relative to another solution. When a cell is placed in a hypotonic solution, water diffuses into the cell, causing it to expand and possibly explode.

- Isotonic solutions: Contain the same concentration of solute and solution. When an cell is placed in an isotonic solution, the water diffuses in and out of the cell at the same rate.

Diffusion: Movement of particles from an area of high concentration to an area of low concentration.

*** These are the mechanisms for PASSIVE TRANSPORT. Passive transport requires no energy.

Active Transport: Movement across cell membrane that requires energy.

Sodium Potassium Pump:

- Protein called The Pump has 3 bonding sides for Na and 1 bonding site for ATP attachment.- 3 Na attach and so does 1 ATP. The ATP is broken down into ADP and P. This provides energy to

change the shape of the pump so that it can dump the Na outside of the cell.- Change in shape. Now has an open side of the pump facing outside the cell and 2 K can attach.- This releases the Pi (inorganic phosphate group) that was still attached to the pump and the

pump shifts shape again, releasing the K inside the cell.- In this way, the ions are moved against the concentration gradient from lower concentration to

higher. This pump is key in maintaining ion levels to ensure stimulus transmission in the nervous system.

Other means of active transport:

Endo/Exocytosis:

(Mr.Amoeba!) :Mr. Amoeba uses his pseudopods to engulf food into himself. ENDOCYTOSIS. Mr. Amoeba’s lysosomes inside of him take the nutrients from the food and separates t from the waste. Mr Amoeba discards of the waste through EXOCYTOSIS.

Pinocytosis: FluidsPhagocytosis: Solids

Chemistry:

Biological Molecule

Common name Elements present

Uses by living things

Monomer and polymer

Example

Carbohydrates Starches and sugars

C,H,O Provide short and longer term energy

Monosaccharide and Polysaccharide

Cellulose

Lipids Fats and oils C,H,O Long term energy and nutrients, cushioning for internal organs

Fatty acids glycerol

Phospholipids

Protein Protein C,H,O,N,S Function as enzymes, act as chemical messengers.

Amino acidsPeptide bond

Keratin

Nucleic Acids DNA and RNA C,H,O,P,N Store’s lifes instructions

Nucleic acids nucleiotides

DNA, RNA

Testing for biological molecules:

1. Test for StarchPlace a little starch powder in a depression on a spot plate. Add a few dropsof iodine. Repeat with sodium bicarbonate.Positive result: blue/black colourNegatvie result: brown colour2. Test for GlucoseBenedict’s reagent contains blue Cu2+ ions that join with monosaccharides.The Cu2+ ions then change colour. Place equal amounts of a strong glucosesolution and Benedict’s reagent in a test tube. Lower the test tube into abeaker of boiling water and wait for two minutes. Repeat with equal amountsof sodium bicarbonate and Benedict’s reagent.Strong positive result: brick red precipitateMedium positive result: yellow orange precipitateWeak result: green colourNegative result: blue colour3. Test for ProteinsAdd a little gelatin solution to a test tube. Add a few drops of Biuret reagent.Repeat with sodium bicarbonate.Positive result: purple colourNegative result: blue colour4. Test for oil and fatPlace a little ethanol in a test tube. Add a few drops of oil and mix by gentlyshaking. Add an equal amount of water and shake again. Repeat with equalamounts of sodium bicarbonate.

Positive result: a cloudy emulsion formsNegative result: liquid remains clear

Photosynthesis and Respiration:

Photosynthesis:

Source of energy: Sun

Process: Chloroplasts capture sun’s energy and make food for plant.

Stages:1. Pigment in Chloroplast captures sunlight.

2. Carbon dioxide and water are used to produce glucose and oxygen.

Chemical Equation: 6CO₂ + 6H₂O ----> C₆H₁₂O₆ + 6O₂

*** Plants are autotrophs, meaning they produce their own food. Heterotrophs obtain nutrients by eating other organisms.

Cellular Respiration:

- Occurs in mitochondria of the cell.- Cells break down food molecules and convert them into ATP energy.

Stage:

1. IN the cytoplasm, glucose is broken down into smaller molecules. A small amount of energy is released.

2. In the mitochondria, the smaller molecules combine with oxygen to produce carbon dioxide and water. Releases a large amount of energy.

C₆H₁₂O₆ + 6O₂---->6CO₂ + 6H₂O

** Humans creating CO₂ is a cause of global warming.

Classification

Taxa:

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Dichotomous Key: Method of classification using process of elimination.

Evidence used in classification:

Evidence from the fossil record:

- Many radioactive isotopes decay at known rates. Scientists use the decay of atoms in the process called radiocarbon dating to find the ages of objects.

Evidence from Biochemistry:

- Comparison of protein molecules among organisms can determine genetic similarities and differences.

Evidence from DNA:

- DNA from different organisms are separated into single strands. Single strands from the two samples are mixed. They bond together. The greater the bonding, the greater the similarities between samples.

Evidence from Anatomy:

- Comparisons in bone structure.

Evidence from Embryonic Development:

- Comparison of early stages of embryonic development.

Bacteria vs. Achaea:

Achaea: cell membrane contains ether linkages; cell wall lacks peptidoglycan; genes and enzymes behave more like Eukaryotes; have three RNA polymerases like eukaryotes; and extremophiles

Bacteria: cell membrane contains ester bonds; cell wall made of peptidoglycan; have only one RNA polymerase; react to antibiotics in a different way than archea do.

When the cell reaches a certain size, it elongates, separating it’s 2 chromosomes. The cell builds a partition between them and eventually the original cell splits into two smaller, genetically identical cells.

Characteristics of different Kingdoms:

Bacteria:

- Prokaryotes- Found in almost every environment due to its ability to uses widely different sources for

energy and nutrition.- Use sexual and asexual reproduction.

Archaea:

- Extremophiles- Cell wall does not contain peptoglycan.- Reproduction is by means of binary fission or conjugation.

Protista:

- Can be autotrophic or heterotrophic.- Eukaryotes.- 3 types: Protozoa (animal like protists)

Algae ( Plant like protists)Slime Moulds and Water Moulds (Fungi-like protists)

Fungi:

- Can be unicellular or multicellular.- Have cell wall- Use extracellular digestion.- Can use sexual or asexual reproduction.

Plantae:

- Vascular: Ferns and their relatives- Seedless Vascular Plants:

Reproduce by spores and have alteration of generation. Sporophyte generation is dominant

- Seed-Producing Vascular plants: Gymnosperms (conifers and their relatives) and Angiosperms (flowering plants). Seeds enable plants to reproduce sexually without water and provide protection

from harsh environments.- Non-Vascular Plants: mosses

Dependant on osmosis and diffusion for the transport of nutrients. No true roots. Life cycle is dominated by haploid, gametophyte phase.

Animalia:

- All except poriferans and cnidarians have 3 germ layers. Ectoderm, mesoderm, endoderm.- Digestive Tract: Almost all animals digest food extracellularly, in a digestive system.- Body symmetry is radial or bilateral depending on type of movement.- Some have a coelom (body cavity) these are coelomates, organs are suspended in coelom.

The coelom allows for development of more complex organs. Some do not have coelom (acoelomates). This means their organs are less complex.

- Some reproduce sexually while others reproduce asexually.

Porifera - Aquatic- Adult body is asymmetrical- Adult is sessile- 2 germ layers, no organs - Single opening in which food enters and waste

leaves.- Digests food intracellularly- No body cavity- Hermaphrodites, reproduce sexually or

asexually- Fertilization in external

Cnideria - Aquatic- Radial symmetry- Some sessile, some free-moving- 2 germ layers, simple nervous system and

muscle tissue- Single opening- No body cavity- Reproduce sexually or asexually, some are

hermaphrodites- Fertilization is external

Platyhelminthes - Live in water, soil or as parasites- Bilateral symmetry- Some motile, some non-motile- 3 germ layers- Distinct head, simple nervous system and

some have excretory- Single opening- Extracellular digestion- No body cavity- Can reproduce sexually or asexually- Internal fertilization, some are

hermaphroditesNematoda - Soil, water or as parasites

- Bilateral symmetry- 3 germ layers- Free living motile, parasitic non-motile- Head and organ systems- Tube within tube body plan- Reproduction is sexual- Fertilization is internal, some are

hermaphroditesAnnelida - Live in water or on land

- Bilateral symmetry- 3 germ layers- Body cavity and organ systems- Tube within tube body plan- Extracellular digestion- Sexual reproduction- Internal fertilization, some are

hermaphroditesMollusca - Most live in water, few on land

- Bilateral symmetry- 3 germ layers- Body cavity with distinct organs- Tube within a tube body plan- Extracellular digestion- Sexual reproduction- Internal fertilization, some are

hermaphrodites

Echinodermata - Live in water- Radial symmetry- 3 germ layers- Body cavity an distinct organs- Tube within a tube- Extracellular digestion- Sexual reproduction- Internal fertilization

Why are anthropods so successful?

- Exoskeleton means that they are well protected- Their joined appendages are adapted for a variety of functions- Well developed nervous system- Way the obtain food, most eat plants

Comparing Vertebrate groups:

Class Amphibia:

- Small lungs- 3 chambered heart- Have tongue, eyelids and limbs

Class Reptilia:

- Better developed lungs ha amphibians and a rib cage- Skin made of keratin- Shed skin several times a year

Class Aves

- Bones are hollow and light for flying- Air sacs in bones moves to the lungs- Maintain their own body heat

Class Mammalia

- Mammary glands- Give birth to young- All have lungs and need oxygen.

Life cycles:

Malaria :

*** we didn’t necessarily use these specific terms in class, this photo is purely to show the cycle, use terms used in explanation.

1. Mosquito feeds on infected person. It ingests reproductive cells of Plasmodium present in red blood cells.

2. The reproductive cells fuse inside of the mosquito to form a zygote. The zygote divides many times to form numerous spore-like cell fragments. Eventually, the zygote breaks open, releasing sporozoites.

3. The sporozoites invade the salivary glands of the mosquito, where they will be injected into a new host.

4. Inside the human host, the sporozoites reproduce asexually in the liver to form a second type of spore-like cells. The new cells invade the bloodstream and invade red blood cells.

5. The blood cells rupture, releasing toxic substances and great numbers of spores. The spores goon to infect more red blood cells.

Frog:

1. Eggs are fertilized.2. Young tadpoles have tail for swimming and gills for respiration3. Older tadpoles start to develop legs

4. Young frogs have well developed legs but no tail.5. Adult frogs are adapted to live on land.

Systems:

Circulatory System:

The circulatory system is comprised of five main parts:

1. The Heart2. Arteries3. Arterioles4. Capillaries5. Veins

Each of the components has a specific job to do in order for the circulatory system to function properly. Circulation Begins in the Heart:

By convention, the circulatory system can be thought of as beginning in the right atrium. In the model of the heart discussed above, this is the upper right-hand chamber of the square. As blood moves through the heart, it passes through each of the four chambers (upper right, lower right, upper left, lower left), takes a quick detour to the lungs (to get rid of carbon dioxide and pick up oxygen) and ends up in the lower left-hand chamber, called the left ventricle.

Left Ventricle:

In the context of pushing blood out to the body and through the circulatory system, the left ventricle is the most important chamber in the heart. It is the largest of the four chambers, and is responsible for generating the force necessary to propel the blood out into the aorta, which is first artery that blood enters as it leaves the heart.

Regulation:

Blood travels from the aorta through a series of smaller and smaller blood vessels until it reaches the capillaries. Before reaching the capillaries, however, blood must travel through the arterioles, where its speed and pressure are constantly adjusted as different segments of the arterioles change diameter in response to pressure and chemical sensors positioned nearby. These sensors adjust blood flow via the arterioles in response to changing conditions in the body.

Capillary Flow:

Because of arteriole action, by the time blood reaches the capillaries it is no longer traveling in a pulsing fashion - blood actually flows continuously through the capillaries, it does not "squirt" and "pause" along with the beating of the heart. This continuous flow is necessary because there is a constant exchange of oxygen and nutrients happening through the walls of the capillaries. No cell in the body is very far away from a capillary.

Closed Loop:

As blood travels through the capillaries, its supply of oxygen is reduced and it acquires waste products. From the capillaries, blood enters the venules and then veins, and travels back to the heart to be refreshed and sent out once again.

Respiratory System:

Lungs:

- An internal respiratory surface connected to the air by means of internal passageways. Lung systems vary from species to species.

- 3 basic elements: o One or two lungs that have a moist respiratory surface.o Some means of forcibly bringing air in contact with the lung surface.o Circulatory system to carry the gases between the lungs and other cells of the body.

3 types of respiration:

- External Respiration: the exchange of oxygen and carbon dioxide between air and blood.- Internal respiration: the exchange of oxygen and carbon dioxide between blood and the cells of

the surrounding tissue.- Cellular respiration: the complex series of chemical reactions that take place mainly in the

mitochondria of the cells.

The respiratory tract; how does air move through the body?

- The air first enters the nostrils which conduct air into the hollow nasal passages where several things occur. Thin bones called turbinates, hang suspended from the nasal chambers. The mucus secreted from the turbinates moistens the air which protects the lungs.

- The air then passes to through the pharynx, the glottis and the larynx.- After passing through the larynx,air goes down the trachea and into bronchioles. - At the end of each bronchiole, there are alveoli. This is wherethe exchange of oxygen and

carbon dioxide occurs.- When the air comes down the trachea, it reaches a fork in the road; bronchus.- The bronchus caries air to the lungs and bronchiole carries air to the alveoli- The diaphragm pushes the air back out.

Lung capacity:

- Average for adult male is about 6L.- Breathing mechanism mammals: tidal breathing; represents volume of air that is inhaled and

exhaled in normal breathing.

Asthma:

- Chronic obstructive lung disease that can occur at any age. Extreme sensitivity of the lungs to certain triggers. Inflammation caused by asthma attacks cause narrowing of airways.

Emphysema:

- Airways become inflamed and filled with mucus. The alveoli become damaged and unable to exchange gases. The elasticity of the lungs is reduced.

Digestive System:

Essential Nutrients: Carbohydrates, Fats, proteins, minerals, vitamins and water.

Mechanical Digestion: Initial stages of physically breaking down food.

Chemical Digestion: Separation of food into its molecular compounds.

Parts of Digestive system:

- Mouth:

o Physically breaks down foodo Papillae: Where taste buds areo Uvula: Prevents food from entering pharynxo Food enters mouth and comes in contact with saliva which assists in the chemical

process of digestion.

Esophagus

- Food passes to the esophagus, lined with muscles that push food along.

Stomach

- Food then passes to the stomach, lined with gastric glands that secrete gastric juice needed for digestion.

- Muscles lining the stomach break down food and mix it with gastric juice to create chyme.

Small intestine

- After exiting the stomach, the food enters the small intestine, which is subdivided into 3 regions: o Duodenum: Shortest and widest region. Pancreatic and bile ducts open into duodenum.

This makes it important in chemical breakdown of food.o Jejunum: breaks down proteins and carbohydrates so the end products can be

absorbed.o Ileum: Absorbs nutrients and pushes undigested material into large intestine.

Large intestine

- Consists of caecum, colon, rectum, and anal canal.- Undigested food entering the large intestine passes up along and down the colon. Here, the

water is dissolved and minerals are absorbed from undigested food, while intestinal bacteria break it down further to provide more nutrients.

- The mass of indigestible material that remains is called feces, it passes through the anal and rectal canal.

Diseases:

- Ulcers: Stomach acid penetrates the stomach wall and it begins to erode, resulting in a slow healing sore known as an ulcer.

- Ileitis: Inflammation of the ileum.

Excretory System:

- Kidneys: filters blood in order to remove cellular waste products from the body.- 3 sections:

o Cortex (outer layer)o Medulla (inner layer)o Pelvis ( inner collecting area)

- Within cortex and medulla there are nephrons which act as filters.- Each nephron consists of the Bowman’s capsule, the proximinal tubule, the loop of Henle, the

distal tubule and the collecting duct.- Blood enters cavity of the Bowman’s capsule through a tiny aretery. The fluid in the Bowman’s

Capsule is the nephral filtrate and it is pushed out of the capsule into the proximinal tubule. When the nephric filtrate enters the proximinal tubule, re-absorbtion begins.Means of active and passive transport draw water, glucose, amino acids and ions from the filtrate into the

surrounding cells. From here the materials return to the bloodstream. Fluid moves to loop of Henle which removes water through osmosis.

- Fluid from nephrons moves from distal tubules into a common collecting duct which carries what is now urine to the renal pelvis.

Disorders:- Kidney failure: Waste begins to accumulate in blood and is treated by dialysis.- UTI: Painful urination etc.

-

Immune system:

Barriers –

Skin and mucus membranes : contain enzymes that destroys pathogens.

Non Specific internale defense:

1. Macrophages engulf pathogen. Phagocytosis.2. Inflammatory response: Damaged tissue secretes histamine which dialates capillaries, bringing

more blood and plasma and healing proteins. Makes capillaries permeable so the plasma and proteins can get into tissues.

3. Blood proteins that disrupt pathogen membranes and metabolic activity. Infereon works on viruses and breaks viral nucleic acid. Compliment interfere with membranes and metabolism.

2 kinds of specific response:

a) Cell mediateda. Macrophage connects the disease antigen to its own protein and puts it on the cell

surface membrane.b. Helper T-cells that have matching shape attach and secrete chemicals that attract and

activate other cells, particularly cytotoxic t-cells.c. Matching killer T-cells are stimulated to divide and make clones.d. Killer T- cells are matched to the pathogen and each can kill many infected cells.

b) Antibody mediateda. Macrophages do the activating but they activate B-cells using protein complexes on

their surface.b. At the same time, they are activating Helper-T cells that connect with B-cells from a and

stimulate them to divide many times.c. A clone of B-cells is produced once helper T-cells stimulate and activate b-CELLS. These

new cells are plasma cells.d. Some clone cells become memory cells and can allow the body to respond faster to the

same infection.e. Plasma cells become antibody producing factories.

Deficiencies:

- Allergies – Body reacts to antigens.