Notes, summaries, assignments, exams, and exercises for Biology for Secondary education

1. Biological Interaction

The interaction function enables organisms to receive changes and stimuli from their environment.

1.1 Stages of Interaction

The interaction function is divided into three stages: perception of stimuli, processing of information, and generation of a response.

• Stimulus: A physical or chemical change that affects the body.
• Receptors: Specialized cells that receive stimuli and transmit information.

Types of Receptors:

• Internal: Perceive changes inside the body.
• External: Perceive changes outside the body.
• Mechanoreceptors: Perceive mechanical stimuli.
• Thermoreceptors: Perceive changes in temperature.
• Nociceptors: Perceive pain.
• Photoreceptors: Perceive changes in light.

1.2 Coordination Centers

Coordination centers receive information...

Chordate Characteristics

Chordates are defined by a dorsal notochord, a supporting rod present in most during embryonic stages. Key features include:

• Dorsal hollow nerve cord: Branches at regular intervals to connect to organs, muscles, and sensory systems.
• Pharyngeal pouches: Paired structures in the throat. In fishes and amphibians, these develop into gills. In humans, they develop into the Eustachian tubes, tonsils, thymus, and parathyroids.
• Post-anal tail: Present at some point during development.

Chordate Classifications

• Chondrichthyes: Sharks and rays.
• Actinopterygii: Ray-finned fish.
• Sarcopterygii: Lobe-finned and lungfish.
• Amphibia: Frogs and salamanders.
• Reptilia: Snakes and lizards.
• Aves: Birds.
• Mammalia: Quadrupeds.

Mammalian Biology

Mammals are...

DNA: Genetic Material

DNA is the genetic material made up of chains of deoxyribonucleotides (A, G, C, T). DNA, except in viruses, comprises two chains of nucleotides. It is found in viruses, in the nucleus of eukaryotic cells (in the form of linear molecules), and in the cytoplasm of prokaryotic cells, some viruses, and some organelles such as mitochondria and chloroplasts (circular shape).

Structure

Primary: consists of a linear sequence of nucleotides.

Secondary: double helix model (Watson & Crick, 1953):

1. Double chains of deoxyribonucleotides.
2. Complementary chains regarding the sequence of bases (A = T, G = C, hydrogen bridge bonds). Each nucleotide in one chain is linked to a nucleotide in the other.
3. In the double helix structure, the nitrogenous

Natural Selection and Sickle-Cell Anemia

This is how natural selection can keep a harmful allele in a gene pool.

• The allele (S) for sickle-cell anemia is a harmful autosomal recessive. It is caused by a mutation in the normal allele (A) for hemoglobin (a protein on red blood cells).
• Malaria is a deadly tropical disease.
• Heterozygotes (AS) with the sickle-cell allele are resistant to malaria. Therefore, they are more likely to survive

Tissue

Tissue: is formed of cells of a similar type that work together to carry out specific functions. Most tissue cells are held together by their own intercellular substances. The human body has four different tissue groups:

Connective Tissue

Connective tissue proper: It surrounds and connects organs and has a gel-like intercellular matrix. Ex: Tendons and ligaments.

Adipose tissue: Stores lipids for protection and energy reserves, using cells called adipocytes.

Cartilaginous tissue: It has a solid, elastic intercellular matrix and cells known as chondrocytes.

Bone tissue: Its rigidity allows it to support the body, along with cartilage.

Blood tissue: It is responsible for the transport of nutrients, hormones and waste, as well as for protecting...

Musculoskeletal and Fascial Structures

• What muscle does the superficial cervical fascia contain?
  Platysma.
• In which part of the mandible is the stylomandibular ligament inserted?
  Angle and posterior border of the ramus of the mandible.
• In which part of the mandible is the lateral pterygoid muscle inserted?
  Neck of the mandible (pterygoid fovea).
• Which two muscles are inserted into the pterygomandibular raphe?
  Buccinator and superior pharyngeal constrictor.
• From which branchial arch are the masticatory derivatives?
  1st branchial arch.
• Which two muscles form part of the medial wall of the infratemporal fossa?
  Tensor veli palatini and levator veli palatini.

Neuroanatomy and Cranial Nerves

• In what part of the brain is the hippocampus located?
  Limbic system (temporal

Trophic Levels in Ecosystems

Producers

Producers are organisms that use photosynthesis to capture energy from sunlight, water, and carbon dioxide to create organic matter (carbohydrates). They also synthesize complex biomolecules such as proteins and lipids. They perform autotrophic nutrition.

Consumers

Consumers are organisms incapable of producing their own basic molecules, requiring them to consume other organisms for nutrition. They perform heterotrophic nutrition and are categorized as follows:

• Primary: Herbivores that consume producers.
• Secondary: Carnivores that consume herbivores.
• Tertiary: Carnivores that consume other carnivores.

Decomposers

Decomposers consume dead plant and animal material, converting it into energy and nutrients for producers....

Human Reproduction Process

Sexual Reproduction Fundamentals

Human reproduction is a form of sexual reproduction. This process involves two gametes (reproductive cells) from different sexes joining together to produce a zygote, which then develops into a new individual.

Gametes, Gonads, and Biological Sex

Gametes are formed in the reproductive organs, known as gonads, which are part of the reproductive system.

• Male Gonads (Testes): Produce spermatozoa (sperm).
• Female Gonads (Ovaries): Produce ova (eggs).

Sex refers to the biological condition determined by an individual's gonads.

Defining Sex and Sexuality

Sexuality is a broader concept that includes biological sex, as well as emotions, feelings, and sex-related experiences. These aspects are not always...

Ecosystem Components and Definitions

An ecosystem is a system formed by different organisms (biocenosis), the environment, its physical and chemical characteristics (biotope), and the interactions that are established between them.

Environmental Factors and Biocenosis

Environmental factors are all the components of the ecosystem that have an impact on the biocenosis. They determine the distribution and composition of the biocenosis, the number of organisms present, and the adaptation of the organisms.

Abiotic Factors and Climatic Conditions

Abiotic factors include physical and chemical components such as temperature, water, and light. Climatic conditions form the large terrestrial ecosystems or biomes.

Biodiversity and Organism Adaptations

Organisms...