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

Evolutionary Biology: Core Principles

1. What is a fossil? A fossil is the preserved remains of an organism.

2. Natural Selection: Natural selection refers to the adaptation of species in different environments. Only the fittest organisms survive to reproduce.

3. Evolutionary Structures:

• Homologous Structures: Structures that share the same evolutionary origin and arrangement of function.
• Analogous Structures: Body parts that have similar functions but do not share a common evolutionary ancestor.
• Vestigial Structures: A body part that no longer serves its original purpose but was likely useful to an ancestor.

4. Darwin's Theory of Evolution: Darwin's theory posits that each living being adapts to its environment. Observations of tortoises and finches...

Health and the Immune System

The World Health Organization (WHO) defines health as a state of complete physical, mental, and social well-being, not merely the absence of disease.

Components of Health

• Physical health: Body systems functioning properly.
• Mental health: Maintaining emotional and psychological balance.
• Social well-being: Fulfillment of basic human needs, including peace, food, education, a decent wage, and social justice.

Note: Any change in the body that results in a loss of health is considered a disease.

Key Medical Terminology

• Aetiology: The study of the causes of a disease.
• Symptoms: Subjective evidence of disease perceived by the patient (e.g., pain, fatigue, sadness, loss of appetite).
• Signs: Objective evidence of disease observed

Activites

1.) Difference between primary and secondary sex characteristics:

The primary are the sexual organs which are born with and the secondary are the physical characteristics developed during puberty

2.) Reproduction:

Is the creation of new individuals

3.) Explain the journey of sperm to the ovum:

After been secreted by the penis through the urethra, the sperm go from the vagina to the uterus, Then, they divide in 2 groups and go to each fallopian tube. If there’s an ovum, one of these single sperm will fertilize it, and they will form a zygote, divides and becomes a morula and later a blastocyst. On the 7 days, the blastocyst implants in the endometrium

4.)

The Endocrine System

Endocrine glands: are glands of the endocrine system that secrete their products, hormones, directly into the blood rather than through a duct.

Hormones: are any member of a class of signaling molecules produced by glands in multicellular organisms that are transported by the circulatory system to target distant organs to regulate physiology and behaviour.

Blood vessels: are the part of the circulatory system, and microcirculation, that transports blood throughout the human body.

Target cell: are cells that respond to a hormone because they possess specific receptors for that hormone.

Receptor: A molecule, usually a protein, that binds to a specific hormone, initiating a cellular response.

Endocrine Signaling Pathway Example

Healthy Habits for Sense Organs

Provide multidirectional protection. Eat a healthy diet, avoid harmful substances, have routine examinations, maintain good hygiene, and avoid injuries.

Specific Preventive Measures

Eyes

• Use sunglasses to prevent overexposure to intense light.
• Read or do precision work in bright light.
• Do not rub your eyes when they itch.
• Rest your eyes periodically; look into the distance regularly when working at the computer.

Ears

• Remove excessive earwax by washing the outer ear; do not insert anything into the auditory canal.
• Avoid loud noise; use headphones at a moderate volume to prevent hearing loss.

Skin

• Shower or wash daily.
• Avoid UV radiation, which causes severe sunburn and skin cancer.
• Cover your body or use sunscreen during the

1. Sequence of Life's Emergence

What is the correct sequence of events representing how life may have emerged?

Answer: Monomers formed — Polymers formed — Membrane-bound "sacs" emerged — Metabolism and self-replication — RNA produced.

2. Identifying Extinct Species

Which species are extinct?

Answer: Species A and E.

3. Common Ancestor Location

In a phylogenetic tree, the common ancestor for both species C and E could be at position number:

Answer: 4.

4. Science of Classification

The area of science that classifies and names organisms is called:

Answer: Taxonomy.

5. Correct Binomial Nomenclature

Which of the following is correctly written using the binomial nomenclature system?

Answer: Canis lupus.

6. Definition of Binomial Nomenclature

Binomial nomenclature...

What Is Mitosis?

Mitosis is a process of cell division that ensures genetic material remains unchanged.

Discovery of Mitosis

Mitosis was discovered in 1882 by Walther Flemming.

Main Features of Mitosis

• It is a type of cell division.
• It occurs in the somatic cells.
• It enables these cells to multiply.
• It produces two daughter cells that are identical to the parent cell after every mitotic division.
• Mitosis lasts about 2 hours.

Phases of Mitosis

Interphase: The duplication of chromatin occurs before cell division.

Prophase: Chromatin begins to condense and chromosomes become visible. In the cytoplasm, the spindle forms.

Metaphase: The chromosomes undergo a particular organization.

Anaphase: The microtubules begin to coil, the connection with the chromatids...

Understanding Nutrition and Eating

Nutrition refers to the process through which the body obtains the matter and energy it needs to grow, repair itself, and perform vital functions. Eating is the process through which we consume the foods that provide us with nutrients.

The Role of Nutrients

Nutrients are the substances cells need to perform vital functions; we get them from food. There are two types of nutrients:

• Organic: Carbohydrates, lipids, proteins, and vitamins.
• Inorganic: Water and minerals.

Classification of Foods

Energy Producing Foods

These are sources of energy, rich in carbohydrates and fats. Examples include butter, cream, and honey.

• Food energy: Foods release the energy they contain. This energy is measured in kilocalories (1 kcal = 1,

Nucleotides: The Building Blocks of Nucleic Acids

Nucleotides are the fundamental structures of nucleic acids. They consist of a phosphate group, a pentose sugar (either ribose or deoxyribose), and a nitrogenous base.

DNA Replication: The Semiconservative Process

DNA replication is the process by which DNA copies itself to ensure daughter cells receive identical genetic information. The resulting molecules consist of two strands: one original strand and one newly synthesized strand, which is why this process is termed semiconservative.

The Replication Process

• The DNA double helix opens and the strands separate.
• Free nucleotides attach themselves to the two separated DNA strands.
• Each nucleotide joins to a complementary nitrogenous base.
• The attached