Notes, summaries, assignments, exams, and exercises for Biology for Other courses

Catabolism. breaking down of complex substances into simples ones to obtain energy.

Relative dating.is a way of using geometric relationship between rocks bodies to determine the sequence of geological events in an area.

Marine trangression. is a geologic events during which sea level rises relative to the land and the shoreline moves toward higher ground, resulting in floading.

Facies fossils. a fossil which exist only in a very specific environment. They show the original conditions of the position.

Anabolism. is the termi given to all the chemical reactions where simple substances are joines together to form more complex ones.

Mass extinction. is the extinction of one or more species in a short period of geological time, this is a consequences...

Sickle Cell Anaemia and Malaria Resistance

Sickle cell anaemia is a genetic mutation in humans characterized by a disorder in the amino acid sequence of the haemoglobin molecule. This results in red blood cells taking on a sickle shape. Malaria is caused by a parasite that thrives in red blood cells; consequently, individuals with sickle-shaped cells possess immunity to malaria. This explains why the condition is more prevalent in tropical regions where malaria is common. However, individuals with sickle cell anaemia typically have a significantly shorter life expectancy.

Artificial and Natural Selection

Artificial selection is utilized to produce varieties of animals and plants with increased economic importance.

Defining Natural Selection

Natural

Plant Parts & Functions

• Roots: Anchorage & Absorption

  Roots provide anchorage for the plant and are responsible for the absorption of water and nutrients from the soil.

• Stems: Support & Transport

  Stems hold the leaves, flowers, and fruits, providing structural support. They also transport fluids (water, nutrients, and sugars) throughout the plant.

• Leaves: Gas Exchange & Vital Processes

  Leaves are the primary sites for gas exchange, which is essential for processes like photosynthesis, transpiration, and respiration.

• Flowers: Reproduction

  Flowers are modified leaves specialized for reproduction. They contain the reproductive organs of the plant.

• Fruits: Seed Protection & Dispersal

  Fruits protect the seeds and facilitate their dissemination

Conjunctival Autoimmune Diseases

Autoimmune diseases associated with skin and mucocicatricial conditions that affect the cornea and conjunctiva:

• Ocular Cicatricial Pemphigoid: Chronic bilateral conjunctivitis that typically appears around 50 years of age, leading to fibrosis, keratinization, and symblepharon. Treatment includes corticosteroids, cyclophosphamide, and dapsone.
• Erythema Multiforme: Includes Stevens-Johnson syndrome (affecting skin and mucosa) and toxic epidermal necrolysis (Lyell's syndrome), often triggered by medication or an infectious process.

Neurotrophic Keratopathy

Etiology: Ablation of the fifth cranial nerve, infection (such as herpes), topical medications (anesthetics), systemic diseases (diabetes mellitus, vitamin A deficiency)...

1. Inorganic Chemical Compounds in Cellular Reactions

Electrolytes are inorganic chemical compounds necessary for cellular reactions.

2. Collecting Tube Reabsorption

Chloride reabsorption in the collecting tube: 1%

3. Urinary Potassium Excretion

Urinary excretion of potassium: 15%

4. Medullary Osmotic Gradient

The countercurrent multiplier mechanism in the loop of Henle creates the medullary osmotic gradient.

5. Urine Acidification

Urine acidification occurs in the collecting tube.

6. Hormonal Control of Blood Pressure

Renin converts angiotensin I in the hormonal control of blood pressure.

7. Glomerular Filtration

Capillary hydrostatic and colloid osmotic pressures determine glomerular filtration volume.

8. Smooth Muscle in Digestive Tract

Longitudinal and...

Tuberal Region of the Hypothalamus

Dorsomedial Nucleus

When stimulated in animals, the Dorsomedial Nucleus produces aggressive behavior.

Ventromedial Nucleus

• Considered the satiety center.
• When stimulated, it inhibits the need to eat.
• Bilateral destruction results in hyperphagia, obesity, and aggressive behavior.

Mammillary Region

Mammillary Nucleus

• Receives input from the parahippocampal formation (subiculum) through the fornix.
• Projects to the anterior thalamic tract through the mammillothalamic tract.
• Associated with Wernicke encephalopathy.

Lateral Nucleus

• Plays a role in thermoregulation (maintaining and increasing heat production).
• Injury to this area results in poikilothermia (the loss of thermoregulation).

Hypothalamic Connections

Afferent Connections

• Septal

Biological Organization: From Subatomic to Organismal Levels

Matter is organized into different degrees of complexity, forming the hierarchical structure of life. These levels include:

• Subatomic Level: Particles that make up atoms (e.g., protons, neutrons, electrons).
• Atomic Level: Formed by individual atoms (e.g., carbon, oxygen, hydrogen).
• Molecular Level: Resulting from the linkage of different atoms. Molecules can be inorganic (e.g., water, salts) or organic (e.g., proteins, carbohydrates, lipids, nucleic acids), with organic molecules being fundamental to living material.
• Cellular Level: The first level of life; the smallest unit capable of independent existence.
• Tissue Level: A network of specialized cells with the same function and origin.

Functions of Nutrition

Nutrition is the set of processes by which living organisms obtain matter and energy from the environment, transform them into living matter, and eliminate waste.

Types of Nutrition

• Autotrophic: Organisms incorporate inorganic substances from the environment, such as CO2 from the air, water, and mineral salts.
• Heterotrophic: Organisms incorporate food produced by other living beings to obtain necessary energy.

Reproduction Function

Reproduction is the set of processes by which living things produce offspring that are either identical (asexual reproduction) or similar (sexual reproduction) to the parents.

Origin of Life

• Stage 1: Chemical evolution
• Stage 2: Prebiotic evolution
• Stage 3: Cellular evolution

Genetics and Cellular Biology

Chromosome:

Primary Structure

Primary Structure: Amino acid sequence, description of all main covalent disulfide bonds and peptide bonds.

• Superfamily: Homology 30%.
• Families: Greater than 50% homology and usually the same function.

Enzymes that break peptide bonds:

• Trypsin
• Chymotrypsin
• Pepsin
• Papain

Predictions from primary structure:

• Homology
• Hydrophobicity
• Secondary structure
• HPLC chromatographic retention
• Accessible and hidden residues
• Mutability

Secondary Structure

Secondary Structure: Folding of the polypeptide chain that occurs due to the formation of hydrogen bonds between the atoms forming the peptide bond.

Structures formed:

• Alpha-helix
• Beta-sheet
• Beta-turn

Examples:

• Alpha-helix: Myoglobin (globular protein), Fibrinogen (fibrous protein)
• Beta-sheet: Fibroin (fibrous

Action Potential: Cellular Electrical Signals

An action potential is a rapid, transient electrical potential change that occurs exclusively in excitable cells, such as neurons and muscle cells. It is fundamental for transmitting information throughout the nervous system and initiating muscle contraction.

Neuron Operation and Signal Transmission

In neurons, excitation typically originates in the dendrites or soma (cell body), and this electrical information is then transmitted along the axon. Many axons are covered with Schwann cells, forming a myelin sheath that allows for faster signal propagation (myelination). It's important to distinguish that when referring to nerve fibers, we mean axons, whereas muscle fibers refer to muscle cells.

Schwann...