Biology Past Paper PDF

CHAPTER 5 | GENETICS ❖ Frameshift Mutation - happens because of the insertion or deletion of nucleotides that are not in ❖ Genetics - study of heredity and genes of living groups of three. org...

CHAPTER 5 | GENETICS ❖ Frameshift Mutation - happens because of the insertion or deletion of nucleotides that are not in ❖ Genetics - study of heredity and genes of living groups of three. organisms. ❖ Tries to know the structure, function, and actions of genes to explain heredity patterns. CHAPTER 6 | MICROBIOLOGY ❖ Genes - basic unit of heredity and will involve DNA ❖ Microbiology - the study of microscopic organisms, ❖ DNA - contains the information for producing proteins such as bacteria, viruses, archaea, fungi, and ❖ DNA Replication - basic and important process protozoa. happening in all living cells of an organism. ❖ Microbes - tiny living things that are found all around ❖ Starts on the DNA molecule known as the us and are too small to be seen by the naked eye replication origin. ❖ Protozoa - tiny living things that are responsible for ❖ Transcription - process by which the genetic diseases: bacteria, viruses, and fungi. information stored in the DNA sequence is copied into the complementary RNA sequence. CHAPTER 6 | BACTERIA STAGES OF TRANSCRIPTION ❖ Bacteria - single-celled organisms ❖ Initiation - binding of enzyme to a region of ❖ Types of Bacteria DNA called promoter ❖ Elongation - RNA polymerase travels along Spherical - bacteria shaped like a ball called DNA to make the chain longer cocci, and a single bacterium is a coccus ❖ Termination - happens when RNA polymerase arrives at a terminator sequence. Rod-shaped - these are known as bacilli (singular bacillus). These are known as vibrio. Types of RNA Spiral - these are known as spirilla (singular ❖ Messenger RNA (mRNA) - blueprint for the spirillus). production or synthesis of proteins. ❖ Streptococcus Group - responsible for strep throat ❖ Ribosomal RNA (rRNA) - primary component of the ribosome. ❖ Spirochetes - spirilla with a very tight coil ❖ Transfer RNA (tRNA) - associated with amino acid ❖ Heterotrophic Bacteria - get their energy through and carries one correct amino acid that matches the consuming organic carbon codon of the mRNA. ❖ Autotrophic Bacteria - make their own food ❖ Translation - process of how genetic information Photosynthesis - using sunlight, water, and stored in mRNA gets converted into a certain protein carbon dioxide or polypeptide molecule. Chemosynthesis - using carbon dioxide, water, STAGES OF TRANSLATION and chemicals such as ammonia, nitrogen, sulfur, ❖ Initiation - small ribosomal subunit connects and others to mRNA close to its start codon ❖ Photoautotrophs - bacteria that use photosynthesis ❖ Elongation - the ribosome progresses along the mRNA and reads its codons to give the ❖ Cyanobacteria - played a vital role in creating the amino acid sequence for the protein. oxygen in the Earth’s atmosphere ❖ Termination - occurs when it reaches a stop codon (UAA, UAG, or UGA) on the mRNA ❖ Chemoautotrophs - bacteria that use sequence. chemosynthesis. ❖ Binary Fission - reproduction of bacteria where a single cell divides into two identical daughter cells. ❖ Mutation - changes in DNA sequence from harmless This can happen every 20 minutes. to damaging ❖ Airborne Bacterial Diseases - Diseases of the ❖ Point Mutation - means a change in one nucleotide Upper Respiratory Tract base pair within the DNA sequence. Streptococcal Diseases (Streptococcal Pharyngitis) ❖ Missense Mutation - causes different amino acids to be added to the protein and this can have an impact Cause: Streptococcus pyogenes on the protein molecule. Symptoms: sore throat, fever, cough, swollen lymph nodes, and tonsils Transmission: Airborne Droplets  Treatment: Penicillin or Clarithromycin Prevention: Pneumococcal vaccine Complications: Rheumatic fever and Acute “Atypical” bacterial pneumonia Glomerulonephritis Cause: Mycoplasma pneumoniae Diphtheria Symptoms: fever, dry cough, diarrhea, and Cause: Corynebacterium diphtheriae vomiting Symptoms: a pseudomembrane forms in the Transmission: Aerosolized droplets throat or nasopharynx, sore throat, low-grade fever Treatment: Erythromycin Transmission: Respiratory Droplets ❖ Foodborne and Waterborne Bacterial Diseases Treatment: Antitoxins and penicillin or Botulism - a severe form of food poisoning erythromycin Cause: nerve toxins produced by Clostridium Prevention: DTaP or Tdap vaccine botulinum Pertussis (whopping cough) Symptoms: blurred vision, slurred speech, and difficulty swallowing or breathing Cause: Bordetella pertussis Treatment: antitoxin Symptoms: fever, increasingly severe cough, leading to the characteristic “whoop” Salmonella Typhi - an acid resistance bacillus that invades the blood Transmission: Respiratory Droplets Symptoms: fever, abdominal pain, rose spots, Treatment: Erythromycin lethargy, and delirium Prevention: DTaP or Tdap vaccine Treatment: typhoid vaccines, chloramphenicol Bacterial Meningitis Vibrio cholerae - infects the small intestines producing enterotoxin Cause: Neisseria meningitidis, Streptococcus pneumoniae, or Haemophilus influenzae Symptoms: profuse watery diarrhea and vomiting Symptoms: headache, rigid neck, vomiting, and sensitivity to bright light Treatment: oral rehydration therapy Transmission: Respiratory Droplets E. coli - can cause various forms of gastroenteritis. Watery diarrhea, caused by enterotoxin production, is Treatment: early diagnosis and penicillin, a typical traveler’s diarrhea. E. coli 0157:H7 is a cefotaxime, or ceftriaxone antibiotics more serious form that can lead to complications ❖ Airborne Bacterial Diseases - Diseases of the called hemorrhagic colitis. Often involves kidneys Lower Respiratory Tract causing hemolytic uremic syndrome (HUS). Tuberculosis (TB) Gastric Ulcers Cause: Mycobacterium tuberculosis Cause: Helicobacter pylori Symptoms: chronic cough, chest pain, high fever Treatment: antibiotics and acid suppressors Transmission: Inhalation of bacilli Treatment: Isoniazid, pyrazinamide, and rifampin ❖ Foodborne and Waterborne Bacterial Diseases require six to nine months Anthrax Prevention: BCG vaccine Cause: Bacillus anthracis “Typical” Bacterial Pneumonia Transmission: inhalation, consumption, or skin Cause: Streptococcus pneumoniae, contact with spores Staphylococcus aureus, and Klebsiella Symptoms: respiratory distress, blood infection; pneumoniae or other species boil-like lesions Symptoms: fever, sharp chest pains, cough, and Treatment: Ciprofloxacin rust-colored sputum Tetanus Transmission: Aerosolized droplets Cause: Clostridium tetani Treatment: Penicillin or erythromycin  Treatment: Tetanus toxoid Penetration - the cell engulfs the virus by endocytosis Leptospirosis - a disease spread from animals to humans (zoonosis) Uncoating - viral contents are released Cause: Leptospira interrogans Biosynthesis - viral RNA enters the nucleus, where the viral RNA polymerase replicates it Symptoms: flu-like Assembly - new phage particles are assembled Treatment: Penicillin or doxycycline Release - new viral particles are made and ❖ Sexually Transmitted, Contact, and Miscellaneous released into the extracellular fluid. Bacterial Diseases ❖ Lysogenic Cycle - Phage DNA integrates into the Syphilis bacterial chromosome Cause: Treponema pallidum ❖ Lytic Cycle - Phage DNA and proteins are Symptoms synthesized inside the host cells and endolysin damages the cell wall, causing the cell to die. Primary: chancre ❖ Remdesivir - blocks the replication of coronavirus Secondary: fever, flu-like illness, rash skin ❖ Viral Diseases of Humans Tertiary: gumma Influenza Congenital syphilis - transmission where a pregnant woman transmits syphilis to the fetus Cause: Orthomyxoviruses: Types A, B, and C Gonorrhea Hemagglutinin and Neuraminidase - necessary for viral entry and exit during an infection Cause: Neisseria gonorrhoeae Prevention: Yearly vaccination Symptoms SARS - represents a newly emerging viral disease Female: vaginal and urethral discharge of pus caused by a coronavirus. In severe illness, and burning during urination insufficient oxygen reaches the blood. Male: urethral inflammation, burning on urination, Cause: Coronavirus and discharge of pus Symptoms: fever, headache, discomfort, body Salpingitis - potential complication and pelvic ached, dry cough, difficulty breathing inflammatory disease Transmission: person-to-person contact Gonococcal Ophthalmia - transmitted when infected women pass N. gonorrhoeae to the Prevention: Yearly vaccination newborn during birth Herpes simplex - a wide spectrum of viral diseases CHAPTER 6 | VIRUS commonly found in the environment HSV-1 - cold sores ❖ Electron Microscope - enabled scientists to see viruses in the 1940s HSV-2 - genital herpes ❖ Nucleocapsid - surround the genome which is Treatment: antiviral drugs usually subdivided into capsomeres Neonatal Herpes - possible life-threatening ❖ Spike Glycoprotein - protrudes from the envelope disease transmitted from a herpes and used for attachment to host cells simplex-infected mother during childbirth ❖ The Viruses and Virus-Like Agents Chickenpox - one of the most highly contagious diseases. Helical: Tobacco mosaic virus, Rabies virus Cause: Varicella-zoster Icosahedral: Herpes simplex virus, Poliovirus Treatment: Acyclovir Complex: Bacteriophage, Smallpox virus Measles Enveloped: Coronavirus Cause: Measles virus (member of ❖ Viral Replication and Its Control paramyxoviruses) Attachment - virus becomes attached to a target Symptoms: hacking cough, sneezing, eye cell redness, sensitivity to light, high fever  Koplic spots: common along the gum line one of the most common infections in people living with HIV/AIDS Mumps Cause: viral infection from another member of paramyxoviruses Symptoms: swollen parotid (salivary) glands, swelling of the testes (orchitis) Polio - affects nervous tissue often leading to permanent paralysis and muscle atrophy Treatment: polio vaccine CHAPTER 6 | FUNGI ❖ Fungi - single-celled or very complex multicellular organisms ❖ Multicellular Filamentous Molds - made up of very fine threads (hyphae) ❖ Mycelium - a network of threads of hyphae ❖ Macroscopic Filamentous Fungi - form large fruiting bodies. These are referred to as mushrooms. They grow by producing mycelium below the ground. ❖ Single-celled Microscopic Yeasts ❖ Fungal Diseases on Humans Fungal Nail Infections - common infections of the fingernails or toenails. Technical Name: Onychomychosis Symptoms: discolored, thick, and fragile nails Ringworm - causes a circular rash that is usually red and itchy. Medical Name: tinea or dermatophytosis Athlete’s Foot - ringworm on the feet Symptoms: itchy skin, ring-shaped rash, scaly cracked skin, hair loss Candidiasis Cause: Candida Vaginal Candidiasis - caused by vagina changed that encourages Candida’s growth Symptoms - vaginal itching or soreness, pain during sexual intercourse, pain when urinating, abnormal vaginal discharge Thrush or Oropharyngeal Candidiasis - candidiasis in the mouth and throat Symptoms: white patches in the mouth, soreness, cotton-like feeling, loss of taste, pain while eating, cracking and redness at the corners of the mouth Candida Esophagitis or Esophageal Candidiasis - candidiasis in the esophagus and