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

Kingdom Monera: Prokaryotic Microorganisms

Monera are prokaryotic, unicellular microorganisms, sometimes forming agglomerations or filamentous structures (like certain Cyanobacteria).

Key Characteristics of Monera

• Reproduction: They reproduce asexually.
• Nutrition: Varied, including heterotrophic (saprophytic) and autotrophic species.
• Metabolism: Varied, including anaerobic and aerobic species.

Metabolic Classification of Bacteria

• Aerobic and Autotrophic Bacteria: Cyanobacteria and green bacteria.
• Chemotrophic Bacteria: Obtain energy by oxidizing molecules, e.g., colorless sulfur bacteria.
• Heterotrophic Bacteria (Saprophytic): Decomposers.

Morphology and Types of Bacteria

Bacteria exhibit varied morphology:

• Cocci (spherical)
• Rods (cylindrical)
• Vibrios
• Spirilla

Infectious and Parasitic Diseases

Prion Diseases

Caused by infectious agents called prions (proteins with a configuration different from the normal protein). Prions are transmitted to other proteins, affecting adjacent organs. Example: Bovine Spongiform Encephalopathy (BSE), commonly known as Mad Cow Disease.

Viral Diseases

Caused by acellular virus particles. Viruses consist of a nucleic acid (DNA or RNA) surrounded by a protein envelope. They self-replicate using the machinery of the infected cell. Treatment is often complicated.

Examples include: Yellow fever, Influenza A, Hepatitis, Mumps, AIDS, and Measles.

Bacterial Diseases

Caused by bacteria, which are unicellular living beings classified as prokaryotes (lacking a defined nucleus). While many...

The Plasma Membrane

The structure of the bacterial plasma membrane is similar to the 75 Å thick unitary membrane found in eukaryotic cells. However, its composition varies slightly, notably lacking lecithin and sterols. The membrane invaginates into the cell to form structures called mesosomes.

Functions of the Plasma Membrane

• Acts as a selective barrier.
• Contains enzymes responsible for synthesizing bacterial cell wall components.
• Mesosomes facilitate the formation of partitions during cell division.
• Contains enzymes that perform cellular respiration.

The Bacterial Cell Wall

The cell wall is composed of carbohydrates and peptides. Its primary component is murein, a peptidoglycan network formed by polysaccharides.

Main Functions of the Cell Wall

• Maintains

The Pharmaceutical Industry and Drug Development

Pharmaceutical companies must make significant investments in the research, creation, and testing of new drugs. To compensate for these investments, each product is protected by patents that grant exclusive exploitation rights for 20 years, preventing other entities from manufacturing or importing expensive marketable medicines.

Drug Approval Process

Before a physician can prescribe a new medication, it must be approved through a rigorous process:

• Preclinical Phase: The drug must pass a series of tests on experimental animals and healthy subjects.
• Clinical Trials: If results are satisfactory, the drug moves to clinical trials to be tested on patients.
• Marketing Authorization: If tests confirm the drug

The Fundamental Units of Life: Cells and DNA

The Cell: The cell is the basic unit of life. It can be divided into two distinct areas: the cytoplasm and the nucleus. The cytoplasm contains various cellular organelles, while the nucleus contains the genetic information that determines the characteristics of every individual: DNA.

Chromosomes and Genes

Chromosomes:

• Tiny threadlike structures found in the nucleus of eukaryotic cells.
• Contain nucleic acids, specifically DNA (deoxyribonucleic acid), and proteins.
• Divided into smaller units called genes.
• The number of chromosomes is characteristic of each species. For example, human cells have 46 chromosomes grouped in pairs, while reproductive cells (gametes) have 23.

Genes:

• The basic unit of heredity in

Mitochondria: Structure and Function

Mitochondria are essential organelles present in all aerobic eukaryotic cells. Their primary function is cellular respiration, the process by which cells generate energy in the form of ATP.

Mitochondrial Membranes and Compartments

Outer Mitochondrial Membrane

The outer mitochondrial membrane is composed of lipids and proteins. Lipids constitute about 40%, with cholesterol being the most abundant. Integral proteins, such as porins, form non-selective channels that allow large molecules to pass through.

Intermembrane Space

This is the narrow space located between the outer and inner mitochondrial membranes.

Inner Mitochondrial Membrane

The inner mitochondrial membrane presents numerous folds inwards, known as mitochondrial

Mitosis and Cytokinesis

Mitosis

Mitosis (discovered by botanist Eduard Strasburger) is a process of nuclear division exclusive to eukaryotes, ensuring the segregation and equal distribution of sister chromatids between the daughter cells during cell division.

Mitosis is an equational division that ensures the conservation of the genetic and chromosomal makeup of the species. Thus, mitosis of a parent cell yields two daughter cells with the same number of chromosomes and genetic information as the parent cell.

Mitosis can be structured into five phases: prophase, prometaphase, metaphase, anaphase, and telophase.

Prophase

During prophase, the following key changes occur:

• Chromatin Condensation: Chromatin condenses into visible chromosomes, each composed

Invertebrate Sensory Organs

Vision

Photoreceptors are grouped. In cnidarians, they are simple eyespots. Flatworms possess more complex structures, resembling eyeglasses. Annelids and gastropods have more complex organs, sometimes featuring a lens (ocelli).

In gastropods, there are two types of eyes:

• Ocelli: These are sensitive only to light.
• Compound eyes: Structured with ommatidia, these simple units result in mosaic vision.

Crustaceans have two compound eyes mounted on mobile stalks. Cephalopods possess camera-type eyes, forming an eyeball containing two types of photoreceptors: cones and rods. They perceive light, shadows, and colors.

Organs of Hearing

Organs receiving sound waves are grouped. Tympanal organs are often derived from tracheal openings...

Nucleic Acids: Fundamental Components of Life

Nucleic acids are naturally occurring substances, first discovered within the cell nucleus. They are characterized by their richness in phosphorus. Scientists later identified molecules of basic character, known as nitrogenous bases: Adenine (A), Guanine (G), Cytosine (C), Thymine (T), and Uracil (U). These are categorized into purine bases (Adenine and Guanine) and pyrimidine bases (Cytosine, Thymine, and Uracil).

They also contain a pentose sugar, which can be either ribose or 2-deoxyribose, but never both simultaneously within the same molecule. RNA typically contains Uracil (U) instead of Thymine (T).

If a nucleotide lacks its phosphate group, it is referred to as a nucleoside. A nucleoside is...

Levels of Biological Organization

The hierarchy of life progresses from the smallest components to the entire planet: Quark, Atom, Macromolecular, Subcellular, Tissue, Organs, Apparatuses and Systems, Individuals, Populations, Communities, Ecosystems, and Biosphere.

Characteristics of Living Beings

• Chemical Composition: Living things are formed by two or more bioelements.
• Structure: Organisms consist of one or more cells, which serve as the fundamental unit of structure, function, genetics, and evolutionary origin.
• Metabolism: The sum of all vital functions based on chemical reactions, including growth, adaptation, irritability, and homeostasis.

Bioelements and Inorganic Molecules

Living beings utilize 27 bioelements to perform three basic functions:...