Notes, summaries, assignments, exams, and exercises for Biology for Vocational training

Origin of the Planet Earth

The formation of our planet occurred in several stages:

1. Formation begins as a ball of gas (nebula).
2. Centuries later, low temperatures allow rocks to appear.
3. Lower temperatures lead to the appearance of seas, oceans, and landscapes. The early atmosphere was initially without rain.
4. The first atmosphere, the protoatmosphere, appears.
5. Chemical reactions over time lead to the first basic life processes.
6. Simple molecules become complex molecules. The first living protobiont (gotes 3500x10^-6) is formed.

Defining Life

Life is a physical process characterized by essential chemical functions, including:

• Nutrition
• Reproduction
• Sensitivity and relationship (interaction with the environment)

Biological and Philosophical Aspects of Death

Diagnosis

Respiratory System

The respiratory system is formed by the ducts through which air circulates, and by small cavities called alveoli, which are capable of entering the bloodstream. At the same time, blood circulates CO2 through the tubes of the respiratory system.

Upper Respiratory Tract

• Nose and nostrils: Two cavities located in the center of the face. Function: To warm and moisten the air.
• Pharynx: Connects the mouth with the larynx and nasal passages. It also communicates through the auditory tube. It forms part of the respiratory and digestive tracts.
• Larynx: Formed by cartilage and bone, it connects the pharynx with the trachea. It contains the vocal cords, which vibrate with airflow to produce the voice.

Lower Respiratory Tract

• Trachea: A tube

Anatomical Planes

Anatomical planes are imaginary lines drawn through the body in the standard anatomical position. They serve to guide and define the position of organs and structures, providing a universal reference system for describing the human body.

Coronal (Frontal) Plane

This vertical plane divides the body into anterior (front) and posterior (back) sections.

Sagittal Plane

This vertical plane divides the body into left and right sections. A midsagittal (or median) plane specifically divides the body into equal left and right halves.

Transverse (Axial or Horizontal) Plane

This horizontal plane divides the body into superior (upper) and inferior (lower) sections.

Anatomical Directional Terminology

These terms describe the relative positions of...

Genetic Code

• Each codon or triplet codes for a specific amino acid.
• It is degenerate: Amino acids can be coded by more than one codon or triplet (some triplets are synonyms). There are 64 codons for 20 amino acids.
• It is not ambiguous: Each codon encodes only one type of amino acid.
• It is universal: Apart from a few small exceptions.
• There are triplets that determine the beginning of translation ('start codon'): AUG (It codes for the amino acid methionine - Met).
• There are triplets that determine the end of translation ('termination' or 'stop' codons): UAA, UAG, UGA (They do not code for any amino acids).

Chromosomes

They are stick-shaped structures that arise from the condensation and packaging of chromatin during the division phases (mitosis and...

Human Nutrition

The cells of all organisms require nutrients to grow and function. Heterotrophic organisms, like humans, cannot produce their own nutrients, so they obtain them from food. Multicellular organisms have many organs grouped into systems, such as the digestive and respiratory systems.

Digestive System

Like all animals, humans obtain proteins, fats, and sugars from food through the digestive system. Food processing involves three phases: digestion, absorption, and waste expulsion. Food moves through the digestive tract via peristaltic movements—muscle contractions in the tract walls that narrow the tube.

Respiratory System

Besides nutrients from digestion, our cells need oxygen for cellular respiration, the process that converts glucose...

Skeletal Striated Muscle Cells

Skeletal striated muscle cells are elongated and have hundreds of peripheral nuclei. The cytoplasmic membrane (sarcolemma) encloses the cytoplasm (sarcoplasm), which is packed with:

• Myofibrils
• Sarcoplasmic reticulum
• T tubules
• Mitochondria

Myofibrils are composed of sarcomeres arranged in series. Each myofibril consists of thin (actin) and thick (myosin) myofilaments.

Sarcomere Structure

The sarcomere (from Greek sarco meaning "flesh" or "meat" and meres meaning "part") features:

• A central, dark A band (anisotropic)
• Two peripheral, light I bands (isotropic)

The sarcomere contains globular proteins such as troponin and tropomyosin. The sliding of thin filaments between thick filaments causes muscle contraction. During contraction,...

Emergency Fracture Management: Initial Steps

When treating fractures, immediate actions are crucial to prevent further injury and stabilize the patient.

• Stop Bleeding: Apply direct pressure to control any external bleeding.
• Calm the Victim: Reassure the injured person to reduce anxiety and pain.
• Remove Jewelry: Carefully remove any rings, watches, or other jewelry from the affected limb before swelling occurs.
• Immobilize the Fracture: Prevent movement of the fractured bone by immobilizing the joint above and below the fracture using any rigid element available.
• Monitor Peripheral Pulse: Regularly check for the presence of a pulse distal to the injury to ensure adequate blood circulation.

Managing Hazardous Fractures

Certain fractures pose significant...

Bacillus Anthracis and Anthrax Disease

Key Characteristics of Bacillus Anthracis

Bacillus anthracis is a bacterium that causes anthrax disease. This bacterium has several defining characteristics:

• It is rod-shaped.
• It can form spores that allow it to survive in adverse conditions for long periods of time.
• It produces potent toxins that can be harmful to humans and other animals.

How Anthrax is Transmitted

The transmission of Bacillus anthracis can occur in various ways, primarily through contact with infected sources:

• Direct contact with infected animals or contaminated animal products such as wool, hide, or meat.
• Inhalation of the bacteria's spores.
• Contact through cuts in the skin (cutaneous exposure).

Clinical Forms of Anthrax

The disease it causes,...

1. How Many Bones Are in the Skeletal System?

206

2. What Is the Largest Bone in Your Body?

Femur

3. Which Job of the Skeletal System Is Like a Factory?

Storing calcium and other minerals.

4. What Are the Skeletal System’s Two Minor Jobs?

To make blood cells and store calcium.

5. The Place Where Two or More Bones Meet Is Called…

Joint

6. The Part of the Bone Where Blood Cells Are Made Is Called…

Marrow

7. These Connect Bones to Muscles:

Tendons (Note: Ligaments connect bone to bone).

8. The Ribs, Sternum, and Spine Protect These Organs:

Lungs, heart, and blood vessels.

9. What Is the Hyoid?

The only floating bone in the skeleton.

10. Skeletal System Components

• Bones: Babies are born with more than adults.
• Ligaments: They connect bone to bone.
• Cartilage: It

Characteristics of Living Organisms

• Respiration and Metabolism

  Cells carry out chemical reactions, such as respiration, to produce energy.

• Reproduction

  The process of creating new organisms, which can be sexual or asexual.

• Nutrition

  Chemical substances used for growth, repair, and other vital functions.

• Growth

  An increase in the size and number of cells.

• Homeostasis

  The ability to regulate the internal environment to maintain it constant or within certain limits.

• Excretion

  The removal of waste products generated by metabolism.

• Movement

  The ability to change position.

• Sensitivity

  The ability to detect changes in the external environment.

Comparing Animal and Plant Cells

Animal Cell Structure

Key components include the nucleus, vacuole, cell membrane, and granular...