Notes, summaries, assignments, exams, and exercises for Biology for Baccalaureate

Skeletal System Disorders

• Osteoarthritis: Occurs when protective cartilage wears down.
• Juvenile arthritis: Arthritis affecting individuals under 16 years old.
• Rheumatoid arthritis: An autoimmune disorder that causes joint inflammation.
• Osteoporosis: Occurs when new bone formation does not keep up with the removal of old bone.
• Rickets: Softening of bones due to a lack of calcium or vitamin D.
• Gout: The buildup of uric acid in the blood and joints.

Types of Bone Fractures

• Greenstick: Incomplete break of the bone.
• Spiral: Caused by excessive twisting.
• Comminuted: Bone is crushed into pieces.
• Transverse: Fracture in a straight line.
• Compound: Exposure of bone through the skin.

Types of Muscle Tissue

1. Smooth muscle: Contracts slowly. Found in blood vessels and

Cell Transport: Endocytosis vs. Exocytosis

• Similarity and Difference:

• Both are forms of active transport (specifically vesicle transport).
• Endocytosis brings materials into the cell, while exocytosis moves them out.

Cell Response to Solute Concentration

Understanding how a cell reacts to different external solute concentrations:

• Hypertonic: More solute outside the cell than inside. Water travels out of the cell.
• Isotonic: Balanced solute concentration inside and outside the cell. Water travels in and out at the same rate.
• Hypotonic: More solute inside the cell than outside. Water travels into the cell.

The Endosymbiotic Theory

Origin of Eukaryotic Organelles

This theory states that organelles such as chloroplasts and mitochondria were once free-living...

The Interaction Function

The interaction function enables people to perceive changes and stimuli that occur both inside their bodies and their environment, to interpret or process them and generate coordinated responses in order to survive.

1.1 Perceiving Stimuli

The interaction function can be divided into 3 stages: perception of stimuli, processing of the information and generation of responses.

A stimulus is a physical or chemical change that takes place outside or inside the body and triggers a response in it.

Our bodies contain specialist cells, called receptors, which perceive stimuli and send the information they detect to the coordination centres.

Types of Receptors

• Internal receptors perceive changes inside the body, such as a rise in blood

Transcription: From DNA to RNA

Steps of Transcription

Initiation

• Transcription begins when transcription factors bind to a specific nucleotide sequence of DNA known as the promoter region or the "TATAA box."
• These transcription factors signal RNA polymerase II to attach to the DNA at the promoter.

Elongation

• Once attached to the DNA, RNA polymerase synthesizes a single-stranded RNA molecule in a 5’ → 3’ direction.
• RNA nucleotides are added to the growing polymer, which are complementary to the DNA template.

Termination

• Eventually, RNA polymerase will reach a termination sequence in the DNA.
• This causes RNA polymerase to release the newly synthesized mRNA and to dislodge from the DNA.

Note: The template strand is also known as the antisense strand,

VII. Antimicrobial Substances

A. The Complement System

The complement system is a vital component of the nonspecific defense system. It consists of a group of serum proteins that activate one another in a cascade to destroy invading microorganisms.

1. Evasion Mechanisms

Some bacteria evade destruction by the complement system through:

• Capsules
• Surface lipid–carbohydrate complexes
• Enzymatic destruction of C5a

2. Functional Groups

Complement proteins form a membrane attack complex that perforates the plasma membrane, causing cell lysis. They are subdivided into three functional groups:

• C1: Recognition
• C4, C2, C3: Activation
• C5–C9: Attack (complement fixation)

3. Complement System Pathways

• Classic Pathway: Antibody binding to pathogen antigens activates

Lymphocyte Migration and Immune Response

Lymphocytes constantly migrate through the blood and lymph, moving from one lymphoid organ to another. This process:

• Enhances the chance that an antibody will encounter its specific antigen.
• The spleen filters blood, while other lymphoid organs filter lymph.

Phagocytosis: A Non-Specific Innate Immune Response

Phagocytosis is the ingestion of microorganisms or particulate matter by a cell. It is performed by phagocytes, which are certain types of white blood cells or their derivatives.

Actions of Phagocytic Cells

1. Among the granulocytes, neutrophils are the most important phagocytes.
2. Enlarged monocytes transform into wandering macrophages and fixed macrophages.
3. Fixed macrophages are located in selected tissues

Infectious Diseases: Causes, Symptoms & Prevention

Common Infectious Conditions

• CP (Common cold): virus - headache, loss of appetite. Keep hydrated.
• Influenza: virus - high fever, pains in back and muscles. Rest.
• Measles: virus - vomiting, diarrhea, sweating. MMR vaccine.
• Tuberculosis: bacteria - weight loss, fever. Antibiotics.
• Bubonic plague: Yersinia pestis (bacterium) - muscle cramps, chills.
• Cholera: bacterial infection - leg cramps, vomiting, diarrhea. Antibiotics.
• Tetanus: bacteria - stiffness. Vaccination or antitoxin.
• Malaria: protozoa - fever, muscle pain, diarrhoea. Medicines.
• Sleeping sickness: protozoa - fever, itchiness. Different medications.
• Athlete's foot: fungus - infection of the skin. Pharmacy creams.
• Ringworm: fungus - a red rash

Nutritional Requirements and Metabolism

Nutrition Defined

Nutrition: Food intake in relation to the dietary needs of the organism.

Autotrophic Nutrition

Autotrophic: The body's ability to synthesize essential substances for metabolism from inorganic substances. Autotrophs have no need for nourishment from other living beings.

Heterotrophic Processes and Transport

Heterotrophic: Done through movements of molecules and ions via the diffusion process. The cell controls its internal chemical composition to regulate the traffic of substances across the membrane. This occurs through two mechanisms:

• Active Transport: Moves against concentration gradients.
• Passive Transport: Moves toward concentration gradients.

Cell Reproduction and Division Cycles

Cell Reproduction

Types of Digestion

Digestion is the process by which complex molecules are broken down into simpler ones. There are two methods of digestion:

• Intracellular Digestion: This takes place inside cells. Each cell functions as a complete digestive system:
  • Food capture (pseudopodia, cilia, or flagella)
  • Food inclusion (endocytosis)
  • Food digestion (lysosomes)
  • Expulsion of undigested material (exocytosis)
  Typical of sponges.
• Extracellular Digestion: This is performed inside the digestive systems consisting of one tract and specialized glands. The nutrients pass into the bloodstream and are distributed to reach all cells. Typical of most animals.

Some animals combine both types of assimilation:

• The food comes in the form of large fragments.
• The inner wall of the