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

Connective Tissue Functions and Components

Connective tissues provide a frame to attach the other tissues of the body, such as body structures, and to protect the internal organs. The intercellular substance of these tissues is very important and is reinforced by a matrix of fibers dispersed and interwoven, and a transparent amorphous extracellular matrix.

Specialized Cell Types

• Fibroblasts: Fixed cells, which are variable.
• Adipocytes; Monocytes: Accumulate fat; WBC migrants. When inflammation occurs, they turn into macrophages that engulf microbes.
• Lymphocytes: Produce antibodies.
• Mast cells: They produce heparin (anticoagulant function) and histamine, which increases the permeability of capillary walls.
• Chromatophores: Stem cells that are very bulky.

The Human Genome

The genome of an organism is the set of all its genetic information. It consists of genes (2%), and the other 98% is composed of RNA genes, introns (extra DNA sequences not used to generate proteins), and junk DNA.

Thus, within the DNA, we can distinguish:

• Sets of nucleotides that form part of the genes: exons and introns.
  • Exon is the portion of DNA within a gene that encodes proteins.
  • Intron is the portion of DNA within a gene that is not used in protein synthesis.
• Junk DNA that does not belong to any gene. Most of the genome is actually non-coding DNA.

Genome and Complexity

Organisms with more genes per nucleotide are not necessarily more complex than organisms with fewer genes per nucleotide.

Genomics is the branch of biology that...

Eutrophication: Causes and Impacts on Aquatic Life

Eutrophication consists of an increase in primary productivity caused by the introduction of bionutrients—inorganic and organic compounds containing nitrogen and phosphorus—primarily through agricultural and domestic discharges.

The contributions of phosphorus and nitrogen fuel the growth of plankton and algae, leading to massive blooms (algal blooms). This dense layer significantly reduces light penetration into the water column.

Phytoplankton photosynthetic activity generates an increase of oxygen on the surface, which often escapes to the atmosphere. Simultaneously, the accumulation of the remains of living organisms intensifies the action of aerobic bacteria. These bacteria consume large...

Gene Therapy: Medical Innovation and Applications

What is Gene Therapy?

Gene therapy is a new way of treating diseases based on the introduction of genetic material into cells to correct a biological problem.

How Does It Work?

You can correct a disease by providing information (as genes) into cells so that they themselves manufacture the active product (protein) needed.

1. Cells are extracted from the patient.
2. In the laboratory, a virus is modified so that it cannot reproduce.
3. A gene is inserted into the virus.
4. The modified virus is mixed with the patient's cells.
5. The patient's cells become genetically modified.
6. The modified cells are injected back into the patient.
7. The genetically modified cells produce the desired protein or hormone.

Objectives of Gene

Classification of Diseases

Traumatic Diseases

Caused by physical injury, such as car accidents, domestic incidents, sporting injuries, or workplace accidents.

• Examples: Bone fractures.

Environmental Diseases

Caused by exposure to ambient factors (cold, heat, radiation).

• Examples: Burns.

Toxic Diseases

Resulting from exposure to environmental toxins or heavy metals.

• Examples: Intoxication.

Metabolic or Nutritional Diseases

Caused by the lack or deficiency of certain nutrients, or resulting from injuries, malformations, or disuse of the body.

• Examples: Diabetes, congenital hypothyroidism, gout.

Degenerative Diseases

Involving anatomical and functional alteration of the tissues within an organ or system.

• Examples: Osteoarthritis.

Genetic Diseases

Caused by genes...

Waste Products

Non-Nitrogenous Products

These include CO2, H2O, mineral salts, and bile pigments. CO2 is removed by respiration. H2O is eliminated through the excretory apparatus and perspiration. Minerals are excreted in urine and sweat, and bile pigments pass out through the digestive system in the feces.

Nitrogenous Products

These are highly toxic compounds eliminated in various forms, such as ammonia, uric acid, and urea. They are categorized into three groups based on the primary excretion product:

• Ammoniotelics: The excretion product is ammonia. Due to its high toxicity, only organisms with abundant water supply can excrete nitrogen this way.
• Uricotelics: The excretion product is uric acid, which is ejected in crystal form. Its toxicity is

Key Concepts in Genetics and Variation

Variations

Differences among individuals within a species.

Phenotypic Variations

Observable differences within individuals of a population (e.g., weight, height, color). These are the result of the environment and the influence of their genotypes.

Genotypic Variations

New features individuals acquire in each generation, typically caused by recombination and/or mutations.

Gene Pool

The sum total of genotypes of all individuals within a given population.

Mutations

Changes that occur in the genetic material. These can be spontaneous or induced and may act favorably or unfavorably on the development of a living being.

Genome

The entire genetic material contained in the cells of a particular organism.

Natural Selection

A

GENETIC ENGINEERING: Genetic engineering is defined as the set of technologies to manipulate the genetic material of a living being, ie modifying genes. This manipulation is basically: "Introducing new genes in a genome. -Remove existing genes in a genome. -Changing the information in a particular gene. The new genetic combinations are introduced into organisms capable of transmission to subsequent generations. Also called recombinant DNA technology, because most techniques rely on DNA fragments recombine. INSTRUMENTS OF GENETIC ENGINEERING: .- Restriction enzymes can recognize a specific DNA fragment and cut. Using different restriction enzymes can get different DNA fragments. Each restriction enzyme recognizes a specific sequence of nucleotides...

Legislation on Stem Cells and Cloning

UN Declarations on Cloning

Resolution adopted on 23 March 2005, stating that practices contrary to human dignity, such as reproductive cloning of humans, must be avoided.

Solemnly declares the following:

• The Member States shall take all measures necessary to adequately protect human life in the application of life sciences.
• Member States shall prohibit all forms of human cloning inasmuch as they are incompatible with human dignity and protection.
• Member States shall take the necessary measures to prohibit the application of genetic engineering techniques that may be contrary to human dignity.

Stem Cell and Cloning Law in Spain

In Spain, the Biomedical Law passed in 2007 allows therapeutic cloning and the obtaining...

Description of the Nervous System

Central and Peripheral Systems

Basic description of the nervous system: The nervous system consists of two major anatomically distinct but interconnected divisions.

• Peripheral nervous system (PNS): composed of groups of neurons called ganglia and peripheral nerves that lie outside the spinal cord and brain (encéfalo). These structures transmit sensory and motor information between the body and the central nervous system.
• Central nervous system (CNS): consists of the brain and the spinal cord (espinal). The CNS integrates information and coordinates activity across the organism.

Spinal Cord and Brainstem

The spinal cord extends from the base of the skull to approximately the first lumbar vertebra and contains motor