Immune Memory, Health, and Genetic Engineering Concepts
Immune Memory and Immunity
Immune memory is what allows the rapid recognition and response to infections. It is a unique and crucial role of the immune system. Immunity is the ability of a person to prevent infection or disease.
Antigens and Antibodies
Antigens: These are proteins or polysaccharides found on the surface of viruses and other pathogens.
Antibodies: These are proteins produced by lymphocytes, which belong to the immune system and act as a defense against viruses, bacteria, parasites, and
Read MoreRNA Transcription: Process and Stages
RNA Transcription: A Detailed Look
Transcription is the process of RNA synthesis, which occurs inside the cell nucleus. This process requires:
- A DNA strand that acts as a template.
- RNA polymerase (RNA-pol) enzyme.
- Ribonucleotide triphosphates (A, G, C, and U).
Ribonucleotides are linked via phosphodiester bonds. The overall process consists of three main stages: initiation, elongation, and termination.
Initiation
RNA polymerase recognizes specific sequences in the DNA that will be transcribed. These sequences
Read MoreExcretory and Nervous Systems: Human Body Functions
Theme 5: The Excretory System
The excretory system includes organs responsible for eliminating waste and foreign substances. It also maintains vital signs, such as the amount of water in the organism and blood acidity.
- Liver: Eliminates products resulting from the destruction of blood hemoglobin.
- Respiratory System: Expels carbon dioxide.
- Sweat Glands: Located in the skin, they produce sweat, which cools the skin when the temperature is high.
- Urinary System: Eliminates waste products through urine.
The
Read MoreHuman Body Systems: Circulatory, Excretory, and Nervous
Circulatory System
The circulatory system involves a continuous loop:
Left auricle → bicuspid valve → left ventricle → aorta artery → vena cava → right auricle → tricuspid valve → right ventricle → pulmonary artery → lungs (alveoli) → pulmonary vein → left auricle.
Blood
Types of Blood Cells
- RBC (Red Blood Cells): No nucleus, contains hemoglobin.
- WBC (White Blood Cells):
- Phagocytes: Engulf bacteria and viruses (phagocytosis).
- Lymphocytes: Produce antibodies.
- Platelets: No nucleus.
Functions
Read MoreUnderstanding Human Digestion and Respiration
The Digestive System: A Detailed Look
Chewing: This is a mechanical process that involves grinding food into smaller pieces to facilitate digestion. Chewing is performed by the teeth, aided by the tongue. Teeth are hard structures containing calcium and fluoride, responsible for crushing food. Types of teeth include:
- Incisors: Used to cut food.
- Canines: Also called tusks, used to tear food.
- Premolars and Molars: Known as molars, their function is to grind food.
Salivation: Saliva, secreted by the salivary
Read MoreMeiosis, Menstrual Cycle, and Histology: Key Concepts
Meiosis
Meiosis: Duplication of DNA, with 2 successive divisions, a mechanism which maintains variability.
Meiosis involves:
- One duplication of DNA, variability through crossing over (metaphase I).
- Two successive divisions: 1st meiotic (prophase I, metaphase I, anaphase I, telophase I, cytokinesis I), 2nd meiotic (II).
Haploid Cells
Haploid cells include sperm and oocytes.
Crossing Over
Crossing over is the exchange of chromatid segments between chromatids.
Prophase I
During prophase I, chromosomes have doubled
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