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

Tipos de Tecidos Animais

Tecido Epitelial: Apresenta pouca substância intracelular, não há vasos sanguíneos, reveste e protege todas as superfícies do corpo.

Revestimento Epitelial (pode estar na semper outside).

Tecido Epitelial Glandular (Secreções: mucosa, serosa e mista; Glândulas: exócrinas (secreção em lança), endócrinas (lançam dentro do corpo) e mistas).

OBS: A queratina aumenta a resistência do epitélio, protegendo o corpo contra micro-organismos e também contra invasão e desidratação excessiva.

Tecido Conjuntivo

Tecido Conjuntivo Propriamente Dito

• Frouxo: fibroblastos (síntese de proteínas), macrófagos (atividade fagocitária) e plasmócitos (produção de anticorpos).

Funções: preenchimento do espaço entre alguns...

Defining the Biosphere and Ecosystems

The biosphere is the set of all living things that inhabit the Earth.

An ecosystem includes all living beings that inhabit a particular place, the relationships established between them, the physical environment where they live, the characteristics of that place, and the interactions between the environment and the organisms.

The ecosphere is the set of all ecosystems on our planet. The biosphere is the living part of the ecosphere.

Key Components of an Ecosystem

Ecology is the science that studies the composition and functioning of ecosystems and is a part of biology.

• Biocenosis (Biotic Community): The whole community of living things in an ecosystem: animals, plants, fungi, etc. Factors related to the presence

The Dual Circulatory System

Humans possess a dual and complete mode of blood circulation. It is considered twofold because, during a full cycle, blood passes through the heart twice, establishing two distinct circuits. It is described as complete because there is no mixing of oxygen-rich blood with carbon dioxide-rich blood. This is possible because the heart is divided by the interventricular septum, which separates the right and left sides, allowing each side to drive blood into a different circuit.

The two established circuits are:

Pulmonary Circuit

This circuit is established between the heart and the lungs. In this process, blood carrying carbon dioxide, collected from all body organs, reaches the right atrium via the superior and inferior...

The Absorption and Egestion

As a result of nutrient digestion, small molecules are obtained, allowing them to pass through the walls of the digestive tract and enter the blood. This process is called absorption.

Most substances are absorbed in the jejunum and ileum. In these sections, the inner walls of the small intestine are highly folded to form villi. Inside the villi, blood vessels collect and distribute digested substances to all body cells.

Egestion

Substances that have not been absorbed pass into the large intestine through peristaltic movements of its walls. In this part, almost all the water and mineral salts are absorbed, so the residues of digestion grow stronger until they become stool.

The large intestine also contains a large number...

Biomolecules and Genetic Information

Biomolecules form long chains, such as in genetic information storage. These chains consist of repeating nucleotides. A nucleotide is composed of a nitrogenous base, a pentose sugar (like am5C), and a phosphate group. A nucleoside is simply a base plus a pentose sugar.

Nitrogenous bases include adenine (A), thymine (T), uracil (U), and guanine (G). Purine bases (A and G) have a two-ring structure, while pyrimidine bases (C, T, and U) have a single-ring structure. These bases contain the genetic code necessary for protein synthesis. Approximately 3000 base pairs are needed to code for a single protein. The human genome contains 46 chromosomes (23 pairs), with 22 pairs being autosomes and one pair being sex...

Assisted Reproductive Technologies

• Artificial Insemination: Used when sperm count is low or motility is insufficient. It involves depositing sperm directly into the reproductive tract.
• In Vitro Fertilization (IVF): Recommended for fallopian tube blockages. Hormones stimulate the production of multiple eggs, which are surgically retrieved, fertilized in a lab, and then implanted into the uterus. This can sometimes result in multiple pregnancies.

Contraceptive Methods

• Barrier Methods: Prevent sperm from reaching the egg. These include the condom (the only method that also prevents STIs) and the diaphragm, a membrane placed over the cervix.
• Anovulatory Methods: Prevent ovulation using hormones, such as birth control pills, injections, or patches.
• Sterilization:

What Is the Human Genome?

The human genome is the complete set of genetic instructions that form human DNA. It represents the entire genetic material of an individual.

What Is the Human Genome Project (HGP)?

The HGP is a scientific initiative focused on sequencing and mapping approximately 30,000 genes within the human species to better understand human biology.

Why Is Understanding the Human Genome Important?

Studying the genome allows researchers to:

• Identify genes responsible for specific diseases.
• Understand how hereditary conditions are passed down.
• Develop targeted, suitable therapies.
• Create diagnostic tools to identify carriers.
• Provide prenatal diagnosis for families with inherited disorders.

What Is Genetic Engineering?

Genetic engineering refers...

The Heart: The Engine of Human Circulation

The heart is the motor of the circulation. If it stops, the brain stops receiving oxygen and dies.

The Phases of the Cardiac Cycle

Every beat of the heart follows a set of phenomena that constitute a cardiac cycle:

• Atrial systole: The atria contract and push blood into the ventricles.
• Ventricular systole: The ventricles contract and the blood leaves through the arteries by forcing the opening of the pulmonary artery and aortic valves. Blood cannot flow backward toward the atria, and its momentum causes the closure of the atrioventricular valves. This closure causes the first heart sound.
• Diastole: The musculature of the heart walls relaxes, but the blood in the arteries cannot flow back toward the ventricles.

In the early 1990s, research on the human being began with the Human Genome Project. In April 2003, the entire nucleotide sequence of the human genome was completed. Today, we know that:

• Our haploid genome (all 23 different chromosomes that we possess) contains 3,000 million pairs of nitrogenous bases, which equates to about 30,000 genes.
• 99.9% of these genes are the same in all people: the differences between us do not represent more than 0.1% of the genome.
• 90% of the genome has no known coding function, which does not mean it has no function, such as gene regulation or various biological controls. It is thought that some of this DNA may correspond to genetic remains of our ancestors.

Applications of the Human Genome Project

The practical applications...

Understanding Human Body Systems

The Locomotor System

The locomotor system allows humans and animals to move and interact with their environment. It consists of the bony system and the muscular system.

The Skeletal System

Components and Functions

The skeletal system includes the human skeleton and its components:

• Bones: Provide internal support. Muscles are attached to bones via tendons.
• Articular Cartilage: Cartilage linking different pieces of bone.

Joints

Structure and Movement

Joints are the junction of skeletal bones and allow a wide range of body movements.

Joint Conditions

Common conditions affecting joints include:

• Dislocation: When a bone is out of the joint.
• Sprain: Injury to the ligaments when joints are stressed.
• Arthritis: An inflammation of