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

Neurological and Mental Health Disorders

• Alzheimer's Disease

  Destruction of neurons in the cerebral cortex, leading to symptoms such as memory loss, disorientation, and behavioral changes.

• Parkinson's Disease

  Characterized by involuntary trembling (especially in the hands) and loss of muscle strength.

• Multiple Sclerosis (MS)

  An immune system-related disorder where the myelin sheaths and neurons destroy each other, affecting the entire body.

• Amyotrophic Lateral Sclerosis (ALS)

  A neuromuscular disorder involving the loss of function and death of motor neurons, resulting in slow paralysis and eventual death.

• Schizophrenia

  A lack of coordination between thoughts, feelings, and actions, often resulting in the person living an isolated life.

• Neurosis

  Chronic

Fundamentals of Genetics

In the nucleus of every cell, there are a number of long threads called chromosomes. Each chromosome is made up of a large number of genes coding for the formation of different proteins, which ultimately determine our characteristics or traits.

Defining Key Genetic Components

DNA (Deoxyribonucleic Acid)

A molecule that carries most of the genetic instructions used in the development of living organisms. It serves as the blueprint for all living things.

Chromosome

A very long DNA molecule that carries a large amount of genetic information.

Gene

A section of a DNA molecule that codes for a specific protein or characteristic (e.g., hair color). A part of a DNA molecule coding for one protein is called a gene.

Trait

A notable feature

Applications of Modern Genetics

• Diagnosis and prevention of genetic diseases.
• Gene Therapy: Treatment of diseases by modifying genes.
• Design of more efficient medicines, enabling personalized treatment.
• New research into human genetics.

Genetic Engineering (GE)

Definition of Genetic Engineering

Techniques used to manipulate genetic material to change an organism's traits.

Stages of Genetic Engineering

1. The gene is located.
2. The gene is isolated. Enzymes are used to cut the DNA in specific places.
3. The gene is attached to a DNA molecule (vector) from a bacterium or a virus to transport it. Recombinant DNA (rDNA) is formed.
4. The rDNA is inserted into a cell so that it can be expressed and synthesize the corresponding protein.

Key Uses of Genetic Engineering

• Biological

The Human Circulatory and Respiratory Systems

Key Components and Functions

1. The Diaphragm's Role in Respiration

The diaphragm separates the thoracic cavity (containing the heart, lungs, and ribs) from the abdominal cavity. It plays a crucial role in respiration. As the diaphragm contracts, the volume of the thoracic cavity increases, drawing air into the lungs.

2. Arteries: Transporting Oxygenated Blood

Arteries are large, thick-walled, muscular blood vessels that carry oxygenated blood away from the heart.

• Pulmonary Arteries: Carry deoxygenated blood from the heart to the lungs.
• Umbilical Arteries: Paired arteries (one for each half of the body) found in the abdominal and pelvic regions. They supply deoxygenated blood from the fetus to the placenta

Key Plant Cell Terms: A Comprehensive Glossary

Amyloplast

Amyloplasts are non-pigmented organelles found in some plant cells. They are responsible for the synthesis and storage of starch granules through the polymerization of glucose. Amyloplasts also convert this starch back into sugar when the plant needs energy.

Cell Wall

The cell wall is a tough, usually flexible but sometimes fairly rigid layer that surrounds certain types of cells. It is located outside the cell membrane and provides these cells with structural support and protection, in addition to acting as a filtering mechanism. A major function of the cell wall is to act as a pressure vessel, preventing over-expansion when water enters the cell.

Nucleus

The nucleus is a membrane-enclosed...

Understanding Health and Disease

Key Definitions

• Disease: A part of our body that changes and ceases to perform its function well.
• Health: Your mental or physical condition.
• Symptoms: A physical or mental feeling experienced by someone with a disease or illness.
• Diagnose: To study symptoms of an illness or disease and to decide what is wrong with a person.
• Sign: A symptom of a disease or illness that is recognized by others.
• Treatment: Medical care or attention given to a person who is ill (curative or symptomatic).
• Convalescence: The period needed for returning to health after illness.

Factors for Maintaining Good Health and Preventing Diseases

• A Healthy Environment: Free of anything harmful to health.
• Healthy Habits and Lifestyles.
• Personal Characteristics.

Biotic Relationships

Biotic relationships are the interactions among living organisms in an environment. There are two main types of biotic relationships:

Interspecific Relationships

Interspecific relationships occur between organisms of different species. These include:

• Mutualism: A relationship where both species benefit. Example: Bees pollinating flowers.
• Commensalism: A relationship where one species benefits, and the other is unaffected. Example: Beetles feeding on mammal excrement.
• Inquilinism: A specific type of commensalism where one organism uses another for housing.
• Parasitism: A relationship where one species (the parasite) benefits at the expense of the other (the host). Example: Cochineals feeding on cacti.
• Predation: A relationship where

The Human Ear: Structure and Function

The ear can be divided into three main sections: the outer ear, middle ear, and inner ear.

Outer Ear

• Auricle (Pinna)

  Consists of cartilage covered with skin. Its primary function is to collect sound waves and direct them into the ear canal.

• Ear Canal

  Extends from the auricle to the eardrum. It contains hairs to help keep out foreign bodies like insects and glands that secrete cerumen (earwax) to protect against water and debris.

Middle Ear

• Tympanic Membrane (Eardrum)

  A thin membrane that vibrates in response to sound waves.

• Ossicular Chain

  Consists of three tiny bones: the malleus (hammer), incus (anvil), and stapes (stirrup). These bones transmit and amplify vibrations from the eardrum to the inner ear.

Inner Ear

• Cochlea

Common Illnesses and Their Causes

Illnesses Caused by Viruses

Viruses are responsible for a variety of illnesses, some of which are highly contagious. Here are a few examples:

• The Common Cold: A highly contagious illness that causes mild discomfort, increased nasal secretions, congestion, and sneezing. It typically does not cause fever. Transmission occurs through direct contact, but the virus can also spread through the air. Frequent handwashing is crucial for prevention.
• Flu (Influenza): Often confused with the common cold due to its prevalence in winter and similar transmission methods. However, the flu generally causes greater discomfort, including joint pain, and is a more serious illness.
• AIDS (Acquired Immunodeficiency Syndrome): A serious

The Menstrual Cycle

Parallel to the changes that occur in the ovarian cycle, a series of cyclical changes take place in the uterine lining, or endometrium, which thickens its walls to prepare to host a fertilized egg. If no fertilization occurs, the endometrium is removed from the uterus and expelled through the vagina, along with the unfertilized egg, during menstruation.

Menstruation (also called menses or a period) is the periodic removal of the endometrium, which carries with it blood, the unfertilized egg, and other fluids.

The Female Reproductive Cycle

• Days 1–5: The cycle begins with menstruation. Simultaneously, the pituitary gland releases FSH, which stimulates the secretion of estrogen and initiates the growth of several follicles in