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

E. Biotechnology

Biotechnology involves the deliberate manipulation of genetic material using the following techniques:

• Recombinant DNA technology: Isolating DNA regions and determining their nucleotide sequences.
• Genetic engineering: Creating genetically modified cells.
• Cloning techniques: Replicating biological entities.
• Tissue culture: Growing cells and tissues in vitro.

F. Genomics

The genome is the complete set of genes within our species, distributed across 23 pairs of chromosomes. The Human Genome Project was established to identify, sequence, and study the function of every gene. Key findings include:

• The human genome contains fewer genes than originally estimated.
• Approximately 25% of the genome consists of non-coding "desert" regions.
• Only

Biological Classification: The Plant Kingdom

Plants are pluricellular, tissue-forming, photosynthetic autotrophs that possess vascular tissue (xylem and phloem).

Non-Vascular Plants (Bryophyta)

Bryophytes live near water (H₂O) due to the necessity for reproduction. They lack vascular tissue and vessels, remaining small. They reproduce through an alternation of generations, involving both sexual and asexual phases.

Vascular Plants (Pteridophytes)

Pteridophytes possess vascular tissue and are cormophytes (having true roots, stems, and leaves).

Seed Plants (Spermatophytes)

Spermatophytes are vascular plants that produce seeds.

Essential Bioelements and Water Properties

Bioelements

These are the elements that form living beings. They are classified as:...

Key Concepts in Genetics

• Gene: A hereditary unit of information; the control unit of a certain character.
• Phenotype: The expressed character, such as plant height or the color of peas.
• Genotype: The hereditary factors received from parents.
• Chromosomes: During cell mitosis, chromatin condenses into filaments known as chromosomes. Humans possess 23 pairs of chromosomes.
• DNA: A molecule that constitutes genetic material and carries hereditary information.
• Central Dogma: The primary pathway establishing how genetic information is stored in DNA and used to synthesize proteins.

Biotechnology and Genetic Engineering

Biotechnology involves techniques used in medicine and biology to create commercial products and improve human health.

Biotechnology Tools

• Restriction

Isoprenoids: Structure and Classification

Isoprenoids are molecules derived from the polymerization of a monomer called 2-methyl-1,3-butadiene (isoprene). These linear or cyclical chains are classified by the number of molecules they contain:

• Monoterpenes: 2 isoprene molecules. These compose plant essences such as menthol in mint.
• Diterpenes: 4 isoprene molecules. Examples include vitamins A, E, and K.
• Triterpenes: 6 isoprene molecules. For example, squalene, from which cholesterol is synthesized in the liver.
• Tetraterpenes: 8 isoprene molecules. These are found in photosynthetic pigments called carotenoids.
• Polyterpenes: More than 8 molecules. Notably, rubber is a polymer composed of thousands of isoprene molecules.

Steroids: Lipid Derivatives

Steroids...

What is Respiration and Its Rates?

Respiration is the physiological process essential to life in aerobic organisms.

The overall chemical reaction of respiration is:

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)

Aerobic Respiration

Aerobic respiration is a type of energy metabolism in which living organisms extract energy from organic molecules, such as glucose, through a complex process where carbon is oxidized and oxygen from the air acts as the oxidizer.

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy (ATP)

Anaerobic Respiration

Anaerobic respiration is a biological process of reducing sugars, oxides, and other compounds where the terminal electron acceptor is an inorganic molecule other than oxygen, or more rarely, an organic molecule. This takes place exclusively...

Antibiotics

They test substances for chemical, biological, or synthetic origin that kill bacteria or prevent their multiplication. After years of research, we succeeded in isolating the substance that prevented the development of bacteria. It was the first antibiotic known as penicillin, discovered by Alexander Fleming. Other antibiotics have been discovered and manufactured in the laboratory; these synthetic antibiotics have a similar effect.

Antiviral

Antivirals act on bacteria; however, they have no effect on other infectious agents. For bacterial infectious diseases, other drugs should not be used.

The importance of certain viral diseases (such as AIDS) has forced pharmaceutical companies to put their efforts into development. It is not easy...

Phosphorus Cycle

Phosphorus reaches the soil with the help of phosphate-solubilizing bacteria, which make phosphates from urine and other organic sources available to plants. Phosphates are carried by surface waters to the ocean basins. Part of these phosphates is lost in the deep ocean, while another portion is taken up by algae and seaweed. From there, phosphates move through aquatic food webs into animals, where they form skeletons, shells, or other remains; those remains are returned to structural components by marine decomposers. Birds that feed on fish recover some phosphates, and their feces accumulate in guano deposits that are exploited industrially for their agricultural importance.

Carbon Cycle

There are major reservoirs of carbon including...

Water & mineral salts were abundant within living organisms, which obtain their substances from the environment (exogenous) or produce other organic molecules (endogenous).

Characteristics:

• Formed by two hydrogen atoms and one oxygen atom (H₂O), linked by covalent bonds.
• Electrically neutral overall, but with a slight positive charge on the hydrogen side and a slight negative charge on the oxygen side.
• Polar, because of its angular structure and its ability to form hydrogen bridges between molecules.

Next:

• High molecular cohesion: it is what allows water to form continuous columns inside vessels and to resist tension.
• High surface tension: the attraction between surface molecules makes possible capillary action, which allows water to penetrate

Biological Classification: Kingdoms and Taxonomy

Kingdom Monera (Prokaryotes)

Characteristics: Prokaryotes that are unicellular and lack organelles. They possess a cell wall composed of murein (peptidoglycan).

Archaebacteria (Archaea)

• Halophiles (salt-loving)
• Methanogens (methane-producing)
• Thermoacidophiles (heat and acid-loving)

Eubacteria (True Bacteria)

Heterotrophic Bacteria

• Forms: Cocci (spherical), Spirilla (spiral), Bacilli (rod-shaped)
• Nutrition: Saprophytic, Symbionts, Commensals, Parasites
• Staining: Gram-positive, Gram-negative

Autotrophic Bacteria

• Chemosynthetic
• Photosynthetic

Kingdom Protoctista (Protists)

Characteristics: Eukaryotes, uni- or pluricellular. Includes autotrophs (algae) and heterotrophs (protozoa).

Autotrophic Protoctists (Algae)

Connective Tissues: Structure and Function

Connective tissues constitute a diverse set of tissues that provide structural support and union. Their cells are scattered and show great variety. The space between the cells is occupied by an intercellular substance or matrix, which contains protein fibers that provide both resistance and elasticity. The most abundant fibers are collagen (for resistance) and elastin (for elasticity), embedded in a gelatinous substance rich in polysaccharides.

Loose Connective Tissue

Loose connective tissue fills the spaces between organs and other tissues. It contains a gelatinous substance and is involved with blood vessels and nerves. Key cell types include:

• Fibroblasts: Fixed, star-shaped or fusiform cells responsible