Biology Exam Review
Biochemistry
1. Characteristics of Life
Cellular organization, the ability to reproduce, growth & development, energy use, homeostasis, response to their environment, and the ability to adapt.
2. Draw a table that shows the monomers and polymers of carbohydrates, proteins, fats and nucleic acids (DNA/RNA). Know the functions of each.
4. Know the levels of protein structure.
Primary Structure: The sequence of amino acids in a polypeptide chain.
Secondary Structure: Local folding into structures like alpha helices and beta sheets due to hydrogen bonding.
Tertiary Structure: The overall 3D shape of a single polypeptide, formed by interactions between amino acid side chains.
Quaternary Structure: The arrangement of multiple polypeptide chains into a functional protein (only in proteins with more than one chain).
5. What is the difference between saturated and unsaturated fat, and types of cholesterol?
Saturated fats: No double bonds, solid at room temperature (e.g., butter, red meat). Can raise LDL (bad cholesterol) and increase heart disease risk.
Unsaturated fats: Have one or more double bonds, liquid at room temperature (e.g., olive oil, nuts). Help lower LDL and raise HDL (good cholesterol), promoting heart health.
Cholesterol Types:
LDL (Low-Density Lipoprotein): "Bad" cholesterol; high levels can clog arteries.
HDL (High-Density Lipoprotein): "Good" cholesterol; helps remove LDL from the bloodstream.
VLDL: Another "bad" cholesterol, carries triglycerides.
Triglycerides: Fats in the blood; high levels can also increase heart disease risk.
6. Explain the induced fit model of enzyme action.
The induced fit model shows that enzymes change shape slightly to fit their substrate. When the substrate binds, the enzyme adjusts to hold it tightly, making the reaction more efficient. After the reaction, the enzyme releases the product and goes back to its original shape.
Cell Biology
1. Be able to sketch a cell membrane and know the key components. Know its function.
Cell membrane controls what enters and exits the cell. It is composed of phospholipids (modified lipid molecules). The head of the phospholipid is hydrophilic (has tendency to mix with water), the tails are hydrophobic (resist water). The heads are usually on the outside of the cell membrane in contact with water while the tails are on the inside.
2. Know diffusion and the three osmotic solutions and how they affect a cell.
Diffusion:
The movement of molecules from high to low concentration without energy.
Osmotic Solutions:
Hypotonic: Water moves into the cell.
Animal cells may burst
Hypertonic: Water moves out of the cell.
Animal cells shrink
Isotonic: Water moves equally in and out.
Animal cells stay normal
3. Discuss the many and varied ways that substances enter and exit the cell.
Facilitated Diffusion:
Passive transport, no energy needed. Large or charged molecules (e.g., glucose, ions) move down their concentration gradient through protein channels or carriers in the cell membrane.
Active Transport:
Movement of substances against their concentration gradient (low to high), requiring energy (ATP).
Bulk Transport:
Transport of large molecules or large quantities across the membrane using vesicles, which requires energy.
Endocytosis: Substances are engulfed into the cell.
Phagocytosis: "Cell eating" – Engulfing large particles or microbes.
Pinocytosis: "Cell drinking" – Engulfing extracellular fluid and dissolved substances.
Receptor-Mediated Endocytosis: Specific molecules bind to receptors before being engulfed (e.g., cholesterol uptake).
Genetics
1. Know mitosis and meiosis.
Mitosis
Goal: To create two identical cells for growth, repair, or replacement.
Phases:
Prophase: Chromosomes condense; spindle fibers form.
Metaphase: Chromosomes align in the center.
Anaphase: Sister chromatids are pulled apart to opposite poles.
Telophase: Two nuclei form, and the cell divides during cytokinesis.
Outcome: Two diploid (2n) cells with the same genetic material.
Meiosis
Goal: To produce gametes (sperm and eggs) with half the chromosome number.
Phases:
Meiosis I: Homologous chromosomes separate (reduction division).
Crossing over (exchange of genetic material) occurs during prophase I.
Independent assortment increases genetic variation.
Meiosis II: Sister chromatids separate (similar to mitosis).
Outcome: Four haploid (n) cells, each genetically different from the parent cell and one another.
2. Understand the chromosome number in each process and how they differ.
Mitosis maintains the diploid (2n) chromosome number (e.g., humans: 46 chromosomes in both parent and daughter cells).
Meiosis reduces the chromosome number from diploid (2n) to haploid (n) (e.g., humans: 46 chromosomes in the parent cell, 23 chromosomes in each gamete).
Purpose:
Mitosis: Produces identical somatic (body) cells.
Meiosis: Produces genetically diverse gametes (sperm and eggs) for reproduction.
3. Know how the final stages in meiosis differ in each sex.
Cytoplasmic Division:
In males, the cytoplasm divides equally, producing four functional sperm cells.
In females, the cytoplasm is distributed unequally, resulting in one large egg and polar bodies, which eventually degenerate.
Timing:
In males, meiosis is rapid and ongoing, beginning at puberty and producing millions of sperm continuously.
In females, meiosis begins before birth, halts at prophase I, resumes at puberty (ovulation), and only completes meiosis II after fertilization.
Gametes Produced:
Males produce 4 sperm cells per round of meiosis.
Females produce 1 viable egg (ovum) per round, optimized for supporting early embryonic development.
4. Know the structure and function of DNA and RNA.
Sugar Type: DNA contains deoxyribose, while RNA contains ribose, making RNA more reactive and less stable.
Strands: DNA is double-stranded, while RNA is single-stranded.
Base Pairing: DNA uses thymine (T), while RNA uses uracil (U) in place of thymine.
Function: DNA stores genetic information permanently, while RNA helps interpret and execute the genetic code for protein synthesis.
5. Know DNA replication.
DNA replication is the process by which DNA makes an identical copy of itself before cell division. DNA replication ensures accurate genetic information is passed to daughter cells. Errors are rare due to the proofreading activity of DNA polymerase.
6. Name the types of mutations and how they occur and their results.
Deletion - due to breakage a piece of a chromosome is lost.
Inversion - chromosome Fragment breaks off, flips around backwards, and reattaches.
Duplication - occurs when gene sequence is repeated
Translocation - Involves two chromosomes that are not homologous. Part of one chromosome is transferred to another chromosome
Non-disjunction - Failure of chromosomes to separate during meiosis. Causes gametes to have too many or too few chromosomes.
7. Know the terms – gene, allele, dominant, recessive, homozygous, heterozygous, hemizygous, carrier, genotype, phenotypes,
Gene: A segment of DNA that contains the instructions for making a specific protein or functional product, which determines a trait.
Allele: A variant or version of a gene. Each individual inherits two alleles for each gene—one from each parent.
Dominant: An allele that expresses its trait in the phenotype even if only one copy is present (e.g., the allele "A").
Recessive: An allele that only expresses its trait in the phenotype if two copies are present (e.g., the allele "a").
Homozygous: When an individual has two identical alleles for a gene (e.g., AA or aa).
Heterozygous: When an individual has two different alleles for a gene (e.g., Aa).
Hemizygous: When an individual has only one allele for a gene, typically seen in males for genes on the X chromosome (e.g., X-linked traits).
Carrier: An individual who carries one recessive allele for a trait but does not express the trait in their phenotype (e.g., Aa for a recessive condition).
Genotype: The genetic makeup of an individual for a specific trait (e.g., AA, Aa, or aa).
Phenotype: The observable physical or biochemical traits of an individual, determined by their genotype and environment (e.g., eye color, height).
8. Be able to work through problems involving simple dominance, incomplete dominance, codominance, sex-linkage, and dihybrids. (define)
Simple Dominance: One allele (dominant) completely masks the other (recessive). Example: Tall (T) dominates over short (t) in plants.
Incomplete Dominance: Neither allele is fully dominant, so the traits blend. Example: Red and white flowers make pink flowers.
Codominance: Both alleles are equally expressed, and both traits show. Example: Blood type AB shows both A and B antigens.
Sex-Linkage: Traits controlled by genes on sex chromosomes (X or Y). Example: Colorblindness is more common in males because it’s on the X chromosome.
Dihybrids: Inheritance of two traits at the same time. Example: Crossing plants for seed color (yellow vs. green) and shape (round vs. wrinkled).
9. Be able to analyze a pedigree.
10. What is nondisjunction? How can chromosomes be analyzed?
Nondisjunction is an error that occurs during cell division (meiosis or mitosis) when chromosomes fail to separate properly. This results in cells with an abnormal number of chromosomes. Karyotyping is a way chromosomes can be analyzed.
11. Know genetic disorders discussed.
Down Syndrome - Trisomy 21
Individuals with Down Syndrome have an extra chromosome of chromosome 21
Mild to moderate intellectual disability
Turne’s Syndrome - XO
One of the parent's sex cells does not contain a sex chromosome
Individuals have only one X chromosome
Phenotypically female - underdeveloped
Dominant Recessive Traits:
Phenylketonuria (PKU):
A homozygous recessive disorder
Causes lack of an essential enzyme that breaks down phenylalanine
Phenylalanine build-up can cause brain damage
Huntington’s Disease:
Due to the presence of a dominant gene. (can be homozygous, but usually heterozygous for the dominant gene)
Symptoms present after 35
Loss of muscle coordination, and mental deterioration because nerves deteriorate
NO treatment or cures
Tay-Sachs Disease:
Homozygous recessive disorder
Lacks enzyme that prevents large fat molecule build up in the brain
Normal at birth, but fat deposits increase and cause damage
Intellectual disabilities, blindness, little muscular activity by age 1
Mutated Gene Disorders:
Cystic Fibrosis:
Caused by a mutation in one gene in the cells that line the respiratory tract and digestive tract
Homozygous recessive condition
Treatments, no cure
Sickle Cell Anemia:
50% of blood cells become sickle-shaped with decreased oxygen supply to tissue
The Digestive System
1. Outline the way your body physically and chemically digests carbohydrates, protein and fat. Include organs, enzymes and hormones. Be able to label a diagram.
Carbohydrates:
Organs: Mouth, small intestine.
Enzymes: Salivary amylase, pancreatic amylase, maltase, lactase, sucrase.
Hormones: None.
End Product: Monosaccharides (e.g., glucose).
Proteins:
Organs: Stomach, small intestine.
Enzymes: Pepsin, trypsin, chymotrypsin, carboxypeptidase, peptidases.
Hormones: Gastrin.
End Product: Amino acids.
Fats:
Organs: Mouth, stomach, small intestine.
Enzymes: Lingual lipase, gastric lipase, pancreatic lipase.
Hormones: Cholecystokinin (CCK).
End Product: Fatty acids and monoglycerides.
2. Make a chart of organ structure and function.
3. Be able to discuss how the structure of organs/organ parts enhances function
4. What are the four types of teeth? How is their structure tied to their function?
Incisors: Sharp, flat teeth at the front used for cutting food.
Canines: Pointed teeth next to incisors, used for tearing food.
Premolars: Flat, broad teeth used for crushing and grinding food.
Molars: Large, flat teeth at the back used for grinding and crushing food into fine particles.
5. Be able to identify disorders discussed in class.
Halitosis (Bad Breath):
Cause: Poor oral hygiene, gum disease, dry mouth, or digestive issues like GERD.
Symptoms: Foul-smelling breath.
Treatment: Good oral hygiene, hydration, and addressing any underlying causes.
Ulcers (Peptic Ulcers):
Cause: Erosion of the stomach or duodenal lining, often due to H. pylori infection or long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs).
Symptoms: Abdominal pain, bloating, nausea, and heartburn.
Treatment: Antacids, antibiotics (for H. pylori), and proton pump inhibitors (PPIs).
Heartburn (Acid Reflux):
Cause: Stomach acid flowing back into the esophagus due to a weak lower esophageal sphincter (LES).
Symptoms: Burning sensation in the chest, regurgitation of acid.
Treatment: Antacids, lifestyle changes, and medications like PPIs.
Hiatal Hernia:
Cause: Part of the stomach pushes through the diaphragm into the chest cavity.
Symptoms: Heartburn, chest pain, difficulty swallowing.
Treatment: Lifestyle changes, medications, and sometimes surgery.
Crohn’s Disease:
Cause: Inflammatory bowel disease (IBD) causing chronic inflammation of the digestive tract.
Symptoms: Abdominal pain, diarrhea, weight loss, fatigue.
Treatment: Anti-inflammatory medications, immunosuppressants, and sometimes surgery.
Appendicitis:
Cause: Inflammation of the appendix, often due to blockage.
Symptoms: Sudden abdominal pain, fever, nausea, and loss of appetite.
Treatment: Surgical removal of the appendix (appendectomy).
Diabetes:
Cause: A condition where the body either doesn’t produce enough insulin or becomes resistant to insulin, affecting blood sugar regulation.
Symptoms: Frequent urination, excessive thirst, fatigue, and slow healing of wounds.
Treatment: Insulin therapy (for Type 1), oral medications, and lifestyle changes (for Type 2).
Hepatitis:
Cause: Inflammation of the liver, often caused by viral infections (hepatitis A, B, C), alcohol use, or autoimmune diseases.
Symptoms: Fatigue, jaundice, abdominal pain, and nausea.
Treatment: Antiviral medications (for viral hepatitis), and lifestyle changes like avoiding alcohol.
Gallstones:
Cause: Hardened deposits in the gallbladder, often due to excess cholesterol or bilirubin.
Symptoms: Sudden pain in the upper right abdomen, nausea, and vomiting.
Treatment: Surgery to remove the gallbladder (cholecystectomy) or medications to dissolve stones.
Diarrhea:
Cause: Can be caused by infections (bacterial, viral), food intolerances, or digestive disorders.
Symptoms: Frequent, watery stools, dehydration.
Treatment: Rehydration, dietary changes, and medications like anti-diarrheal agents.
Constipation:
Cause: Slow movement of stool through the colon, often due to poor diet, dehydration, or lack of physical activity.
Symptoms: Infrequent or difficult bowel movements, bloating.
Treatment: Increased fiber intake, hydration, exercise, and laxatives if necessary.
The Respiratory System
1. Outline the path of an oxygen molecule as it travels from the atmosphere into the bloodstream.
Nose/Mouth → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli
Gas Exchange occurs in the alveoli, where oxygen diffuses into the bloodstream and binds to hemoglobin in red blood cells. Oxygenated blood is carried to the heart and then pumped to the rest of the body through arteries.
2. Make a chart of organ structure and function.
3. Be able to discuss how the structure of organs/ organ parts enhances function.
4. Know the functions of the respiratory system.
5. Know disorders discussed in class.
Pneumonia involves an infection of the lungs with symptoms like cough, fever, and difficulty breathing.
Chronic Bronchitis is marked by long-term inflammation and mucus production in the airways, often due to smoking.
Asthma is a condition where the airways constrict, making breathing difficult, often triggered by allergens or irritants. Treatment include: Inhalers (bronchodilators for quick relief and corticosteroids for long-term control), avoiding triggers, and maintaining good overall lung health.
Emphysema involves the destruction of lung tissue, reducing oxygen exchange, often caused by smoking.
Cystic Fibrosis is a genetic disorder that causes thick mucus buildup in the lungs, leading to breathing difficulties and infections.
Lung Cancer is a malignant growth in the lungs, often caused by smoking, with symptoms like cough, chest pain, and difficulty breathing.
6. Be able to discuss regulatory mechanisms – blood pH etc.
Blood pH: Regulated through buffer systems, respiratory control (CO₂), and renal function.
Blood Glucose: Maintained by insulin and glucagon, with the liver storing and releasing glucose.
Body Temperature: Controlled by the hypothalamus with responses like sweating and shivering.
Electrolyte and Fluid Balance: Regulated by the kidneys and hormones like ADH and aldosterone.
Blood Pressure: Adjusted by baroreceptors and hormones such as RAAS and ADH.
7. Be able to explain gas exchange at the alveoli and tissue level.
The entire process is driven by diffusion, where gases move from areas of higher concentration to areas of lower concentration.
At the Alveoli: Oxygen enters the bloodstream, and carbon dioxide is removed from the blood.
At the Tissues: Oxygen is delivered to cells for metabolism, and carbon dioxide is collected from cells to be removed by the lungs.
Circulatory System
1. Be able to distinguish between types of circulation.
Pulmonary Circulation:
Carries deoxygenated blood from the right side of the heart to the lungs and back to the left side of the heart.
Coronary Circulation:
Supplies the heart muscle with oxygen-rich blood via coronary arteries branching from the aorta.
Oxygen-poor blood returns to the right atrium.
Systemic Circulation:
Delivers oxygen-rich blood from the left side of the heart to the body and returns oxygen-poor blood to the right side.
2. Know the functions of this system.
To deliver oxygen and nutrients to the cells
To remove Carbon dioxide and wastes from the cells
To carry hormones from the body
To provide defense for the body by transporting WBC
3. Be able to explain how the structure of arteries, veins and capillaries are suited to their function. Know visually and their key features.
4. Be able to describe the structure and function of blood components.
Red Blood Cells (RBCs):
Structure: Biconcave, no nucleus, contains hemoglobin.
Function: Carry oxygen to tissues and carbon dioxide back to the lungs.
White Blood Cells (WBCs):
Structure: Larger, with a nucleus, various types (e.g., lymphocytes, neutrophils).
Function: Defend against infections and support immunity.
Platelets:
Structure: Small, irregularly shaped cell fragments.
Function: Help clot blood and stop bleeding.
Plasma:
Structure: Yellowish liquid, mostly water with proteins and nutrients.
Function: Transports nutrients, hormones, waste, and aids in clotting and immunity.
5. Be able to discuss the role of the different blood cells (Red and white)
6. Know the role of platelets in clotting.
Facilitates adhesion to damaged sites. Releases substances that recruit more platelets and activate clotting factors. Helps stabilize the clot and pull the wound edges together.
7. Be able to discuss how O2 and CO2 are picked up and released by hemoglobin.
Partial Pressure of Gases: Hemoglobin binds or releases oxygen and carbon dioxide depending on their concentration gradients in the lungs or tissues.
pH (Bohr Effect): A lower pH (higher acidity) reduces hemoglobin’s oxygen affinity, aiding in oxygen delivery to active tissues.
Temperature: Increased temperature (e.g., during exercise) promotes oxygen release.
8. Know the structure of the heart and be able to label.
10. Initiation and regulation of heart beat.
Initiation (Intrinsic Conduction System):
The SA node generates electrical impulses that set the heart's rhythm.
The impulse travels to the AV node, then through the Bundle of His and Purkinje fibers, causing atrial and ventricular contractions.
Regulation (Extrinsic Control):
Sympathetic nervous system increases heart rate and force during stress (via norepinephrine).
Parasympathetic nervous system decreases heart rate during rest (via acetylcholine).
Hormones like adrenaline and thyroid hormones increase heart rate, while physical activity, temperature, and electrolyte levels also influence it.
12. Be able to discuss factors affecting bp., normal values and what it is, how its measured.
Normal BP: 120/80 mm Hg.
BP Measurement: Done using a sphygmomanometer and stethoscope, reading systolic and diastolic pressure.
Factors Affecting BP: Heart rate, blood volume, resistance, stress, lifestyle choices, genetics, and medical conditions.
13. Know disorders discussed in class and ways of diagnosing them.
Hypertension (High Blood Pressure):
Definition: A condition where the force of blood against artery walls is too high.
Symptoms: Often none, but can include headaches, dizziness, and nosebleeds.
Causes: High salt intake, lack of exercise, obesity, smoking, genetics.
Treatments: Healthy diet, exercise, weight loss, medications (e.g., diuretics, beta-blockers).
Anemia:
Definition: A condition where the blood lacks enough healthy red blood cells or hemoglobin.
Symptoms: Fatigue, weakness, pale skin, shortness of breath, dizziness.
Causes: Iron deficiency, vitamin deficiencies, chronic disease, blood loss.
Treatments: Iron supplements, vitamin B12 or folic acid, treating the cause of blood loss.
Sickle Cell Anemia:
Definition: A genetic disorder where red blood cells become sickle-shaped and block blood flow.
Symptoms: Pain episodes (crises), fatigue, swelling, frequent infections.
Causes: Inherited genetic mutation in hemoglobin.
Treatments: Pain management, blood transfusions, medication (e.g., hydroxyurea), bone marrow transplants.
Heart Attack (Myocardial Infarction):
Definition: A blockage of blood flow to the heart muscle, leading to tissue damage.
Symptoms: Chest pain, pain in the arm or jaw, shortness of breath, sweating, nausea.
Causes: Blocked coronary arteries due to plaque buildup (atherosclerosis).
Treatments: Medications (aspirin, clot busters), surgery (angioplasty, bypass), lifestyle changes.
Leukemia:
Definition: A cancer of the blood where the bone marrow produces abnormal white blood cells.
Symptoms: Fatigue, frequent infections, easy bruising, weight loss, bone pain.
Causes: Genetic mutations, exposure to radiation/chemicals.
Treatments: Chemotherapy, radiation therapy, stem cell transplants, targeted therapy.
Hemophilia:
Definition: A genetic disorder where blood doesn’t clot properly, leading to excessive bleeding.
Symptoms: Prolonged bleeding, easy bruising, joint pain from internal bleeding.
Causes: Lack of clotting factors (genetic, often X-linked).
Treatments: Clotting factor replacement therapy, desmopressin for mild cases.
Polycythemia:
Definition: A condition where the body produces too many red blood cells.
Symptoms: Headaches, dizziness, itchy skin, high blood pressure, redness of the face.
Causes: Bone marrow overproduction (polycythemia vera), low oxygen levels (secondary polycythemia).
Treatments: Phlebotomy (blood removal), medications to lower red blood cell count.
Angina:
Definition: Chest pain caused by reduced blood flow to the heart muscles.
Symptoms: Tightness or pressure in the chest, pain in the neck, arms, or back.
Causes: Coronary artery disease (narrowed arteries due to plaque).
Treatments: Medications (nitroglycerin), lifestyle changes, surgery (angioplasty).
Stroke:
Definition: A condition where blood flow to the brain is interrupted, causing brain damage.
Symptoms: Sudden numbness or weakness (especially on one side), confusion, trouble speaking, dizziness.
Causes: Blocked or ruptured blood vessels in the brain (clot or hemorrhage).
Treatments: Clot-busting medications, surgery, physical therapy for recovery.
Aneurysm:
Definition: A bulge in a blood vessel due to a weakened artery wall.
Symptoms: Often none, but can include sudden severe pain if it bursts (depending on location).
Causes: High blood pressure, injury, genetic factors, atherosclerosis.
Treatments: Monitoring, surgery (repair or stent placement), blood pressure control.
Phlebitis:
Definition: Inflammation of a vein, often in the legs.
Symptoms: Pain, redness, and swelling along a vein, warmth around the area.
Causes: Prolonged immobility, infection, injury, blood clots (thrombophlebitis).
Treatments: Compression stockings, anti-inflammatory medications, treating any clot with blood thinners.
Edema:
Definition: Swelling caused by excess fluid trapped in the body’s tissues.
Symptoms: Swelling in the legs, ankles, or feet, stretched or shiny skin, shortness of breath.
Causes: Heart failure, kidney disease, sitting or standing for long periods, pregnancy.
Treatments: Diuretics (water pills), raising the affected limb, reducing salt intake.
Varicose Veins:
Definition: Enlarged, twisted veins, often in the legs.
Symptoms: Bulging veins, aching or heavy legs, swelling, itching around the veins.
Causes: Weak or damaged vein valves, leading to blood pooling in veins.
Treatments: Compression stockings, lifestyle changes (exercise), surgical removal or closure of veins.
Evolution
1. Know key terms like fossils, paleontology, archaeopteryx, Homologous features, Analogous features, and Vestigial features.
Fossils: Preserved remains of ancient organisms, providing insight into life's history.
Paleontology: The study of fossils and ancient life forms.
Archaeopteryx: A key fossil linking dinosaurs and birds, showing evolutionary traits of both.
Homologous Features: Structures from a common ancestor, showing evolutionary relationships.
Analogous Features: Similar traits with different evolutionary origins, resulting from convergent evolution.
Vestigial Features: Reduced or non-functional structures from ancestors, providing evidence of evolution.
2. Know early ideas about evolution.
3. Know Darwin’s Theory of Natural Selection.
Darwin’s theory of natural selection explains how species evolve and adapt over time, driven by environmental pressures and competition for survival. Natural selection is the process where organisms with traits better suited to their environment are more likely to survive, reproduce, and pass those traits on. Over time, this leads to the adaptation of species to their surroundings.
4. Know Modern Synthesis, Random Change in DNA, Genetic Drift, Gene Flow.
Modern Synthesis: The combination of natural selection and genetics to explain evolution.
Random Change in DNA: Mutations that introduce new genetic variations, which may affect evolution.
Genetic Drift: Random changes in allele frequencies in a population, particularly in small populations.
Gene Flow: The movement of genes between populations through interbreeding, which increases genetic diversity.
5. Be able to explain patterns of selection.
Directional Selection: Favors one extreme trait, shifting the population in one direction (e.g., darker moths).
Stabilizing Selection: Favors intermediate traits, maintaining the status quo (e.g., average human birth weight).
Disruptive Selection: Favors extreme traits, leading to two distinct groups (e.g., finch beaks).
Sexual Selection: Favors traits that increase an individual's chances of attracting a mate (e.g., peacock tails).
6. Formation of a species.
Speciation is a gradual process that leads to the formation of new species, contributing to the biodiversity we observe in the natural world.
Reproductive Isolation: Populations must become reproductively isolated to form new species. This can be through prezygotic or postzygotic barriers.
Allopatric Speciation: Geographic isolation leads to speciation.
Sympatric Speciation: Speciation occurs without geographic isolation, often due to behavioral or genetic changes.
Parapatric Speciation: Populations are partially isolated and evolve in different environments, eventually leading to reproductive isolation.
Adaptive Radiation: Rapid diversification of a species into many forms due to new environments or ecological opportunities.
Genetic Drift and Gene Flow: These factors can either promote or inhibit speciation depending on their influence on gene pools.
7. Know Human Evolution
Human evolution is a long process that started with early primates and led to the emergence of Homo sapiens.
8. Adaptive Radiation, Convergent, Divergent Evolution.
Adaptive Radiation: Rapid diversification from a single ancestor into many species, each adapted to different niches (e.g., Darwin's finches).
Convergent Evolution: Unrelated species evolve similar traits due to similar environmental pressures, not shared ancestry (e.g., wings of bats, birds, and insects).
Divergent Evolution: Related species become more dissimilar due to different environmental pressures, leading to speciation (e.g., wolves and domestic dogs).
Biodiversity
Taxonomy and level of organization, Kingdom, Phylum…
To remember the taxonomic hierarchy, you can use this mnemonic: "Domain King Philip Came Over From Germany Swimming"
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Eukaryotic vs. Prokaryotic Cells (info. and be prepared to label)
Nucleus: Eukaryotes have a nucleus; prokaryotes do not.
Size: Eukaryotes are larger; prokaryotes are smaller.
Organelles: Eukaryotes have membrane-bound organelles; prokaryotes do not.
DNA: Eukaryotes have linear DNA in the nucleus; prokaryotes have circular DNA in the nucleoid.
Complexity: Eukaryotes are more complex with multiple internal structures; prokaryotes are simpler.
Viruses, Lytic Cycle, Bacteriophage parts
Viruses:
Viruses are tiny infectious agents made of genetic material (DNA or RNA) surrounded by a protein coat (capsid), sometimes with an outer lipid membrane (envelope). They cannot replicate on their own and must infect a host cell.
Lytic Cycle:
The lytic cycle is a process where a virus infects a host cell, takes over its machinery to replicate, and causes the host cell to burst, releasing new viruses. The steps are:
Attachment: Virus binds to the host cell.
Entry: Virus injects its genome into the host.
Replication: Host cell makes copies of the virus.
Assembly: New viral particles are assembled.
Release: Host cell bursts, releasing the new viruses.
Bacteriophage Parts:
A bacteriophage is a virus that infects bacteria. Its parts include:
Head: Contains viral DNA/RNA.
Tail: Helps attach to the host bacterium.
Tail Sheath: Contracts to inject viral DNA.
Base Plate: Assists with attachment to the bacterial surface.
Prokaryotes- bacterial shapes, cell wall types and gram positive or negative, binary fission, conjugation and transduction.
Bacterial Shapes: Cocci (sphere), Bacilli (rod), Spirilla (spiral), Vibrio (comma).
Cell Wall Types: Gram-positive (thicker peptidoglycan, purple) vs. Gram-negative (thinner peptidoglycan, pink).
Binary Fission: Asexual reproduction resulting in two identical bacteria.
Conjgation: Transfer of genetic material between bacteria through direct contact.
Transduction: DNA transfer between bacteria by a bacteriophage.
Protists- Diagrams of paramecium, euglena, amoeba- methods of movement, methods of eating (classification).
Protists are a diverse group of eukaryotic organisms that do not fit into the other kingdoms (animals, plants, fungi). They are mostly unicellular, though some are multicellular. Protists can be found in various environments, especially in aquatic habitats, and can have characteristics similar to animals, plants, or fungi.
Movement Methods: Protists move using pseudopodia (amoeboid movement), cilia (ciliary movement), flagella (flagellar movement), or gliding (via secretion or protein filaments).
Feeding Methods: They can eat through phagocytosis (engulfing food), ciliary feeding, photosynthesis (in autotrophic forms), absorption (in fungus-like forms), or a combination of these (mixotrophy).
Fungi
Fungi are eukaryotic, heterotrophic organisms with a variety of forms, including molds, yeasts, mushrooms, and lichens. They acquire nutrients through absorption and play key roles as decomposers, symbionts, and pathogens in ecosystems. Fungi reproduce through spores and can have both sexual and asexual reproductive cycles. Their importance extends to food production, medicine, and environmental roles.
Protists- types of movement, ways of getting energy
They obtain energy in different ways, including phagocytosis (engulfing food), ciliary feeding, photosynthesis, absorption (as saprotrophs or parasites), or a mix of these strategies (mixotrophy).