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

Prime Mover Muscles and Their Functions

• Iliopsoas: Prime mover of thigh flexion.
• Tibialis Anterior: Prime mover of dorsiflexion.
• Extensor Digitorum Longus: Prime mover of toe extension.
• Tibialis Posterior: Prime mover of foot inversion.
• Pectoralis Major: Primary arm flexor.
• Subscapularis: Prime medial rotator of the humerus.
• Serratus Anterior: Prime mover to protract and hold the scapula against the chest wall.
• Diaphragm: Prime mover of inspiration.
• Erector Spinae: Prime mover of back extension.
• Deltoid: Prime mover of arm abduction.
• Sternocleidomastoid: Prime mover of head flexion.
• Masseter: Prime mover of the jaw.
• Triceps Brachii: Prime forearm extensor.
• Extensor Digitorum Communis: Prime mover of finger extension.

Central Nervous System: The Hypothalamus

Vital

Fundamentals of Biological Molecules and Bonds

Essential Elements and Molecular Formation

The primary elements that form biological molecules are often summarized by the acronym CHOMPS (Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur). Carbon (C) is highly versatile, forming the backbone of organic compounds.

Monomers, Polymers, and Reactions

• Monomers: The smallest units of organic compounds.
• Polymers: Large molecules formed by repeating monomer units (M + M = Polymer + H₂O).
• Polymerization: The process of forming polymers.
• Dehydration Synthesis: A reaction where monomers join to form a polymer, releasing a water molecule (H₂O).
• Hydrolysis: A reaction that breaks down a polymer by adding a water molecule.

Chemical Bonds and Essential Elements

Molecules...

Understanding Mitosis and Cell Division

Mitosis is a way of producing new cells. It takes place when organisms are growing or replacing damaged cells. Asexual reproduction is a type of reproduction that involves only one parent. During mitosis, the nucleus of the cell divides so that the daughter cell has an identical set of genes as the parent cell. Genes are carried in the nucleus in long strings called chromosomes. Nearly all cells contain 46 chromosomes in each nucleus. The newly formed cells are called clones, which are exact replicas of the parent cell.

Meiosis and the Production of Gametes

Meiosis is another way of producing new cells. It results in gametes, which have half the number of chromosomes as the parent cell. It happens in the...

Circulatory and Lymphatic Systems

Key Components and Functions

• Platelets: A small, irregularly shaped, disk-like cytoplasmic body found in blood plasma that promotes blood clotting. It has no definite nucleus, no DNA, and no hemoglobin. Also called a blood platelet or thrombocyte.
• Lymphatic System: Responsible for the removal of interstitial fluid, the extracellular fluid that bathes most tissue. It also acts as a highway, transporting white blood cells to and from the lymph nodes.
• Heart’s Natural Pacemaker: The sinoatrial (SA) node.
• Dialysis: Provides an artificial replacement for lost kidney function.

Common Questions

How are lymph vessels and veins similar?

Just as blood flows through veins, lymph fluid flows through lymph vessels.

What structure

Cellular Respiration Explained

Respiration is the process in which glucose and oxygen are transformed inside the cell into water, carbon dioxide, and energy.

The goal is to transform glucose and oxygen into energy.

Gases involved are oxygen, which we use, and carbon dioxide, the result.

It happens inside the cell in the mitochondria.

Defining Metabolic Rate

Metabolic rate is an average of the amount of energy that a person needs. While sleeping, we spend energy in circulation, for development, breathing, and protection. We spend energy because the body is working constantly.

Function of the Breathing System

In breathing, gases are exchanged. Oxygen goes from the air to the blood, and carbon dioxide goes from the blood to the air.

Lining of the Respiratory

Reproduction in Flowering Plants

The reproduction of flowering plants involves several key steps:

• Pollination: Pollen is transferred from the male stamen to the female stigma. Pollen is carried by insects or the wind.
• Fertilization: When pollen lands on a stigma of the same species, the pollen grain grows a tube to join with the female sex cell (gamete), known as the ovule.
• Seed Dispersal: After fertilization, the flower’s petals fall off and a fruit usually forms from the ovary. The fertilized ovules form seeds, which are dispersed by wind or animals.
• Seed Germination: Seeds begin to grow when temperature, air, and water conditions are optimal.

Sexual Reproduction in Animals

Sexual reproduction requires two individuals of different sexes, each...

The Endocrine System

The endocrine system is comprised of glands that produce protein substances called hormones. These hormones act as chemical messengers, speeding up or slowing down various activities within the body's cells.

Types of Glands

Exocrine Glands

Exocrine glands release substances through ducts to specific locations. These substances include enzymes, oil, and sweat. Examples include:

• Salivary glands
• Sweat glands
• Oil glands
• Gastric glands
• Intestinal glands

Endocrine Glands

Endocrine glands produce and secrete hormones directly into the bloodstream, acting on target cells throughout the body. Examples include:

• Pituitary gland
• Thyroid gland
• Adrenal glands
• Ovaries
• Testes

Hormones: Action and Functions

Hormones act on specific target cells by binding...

Function of the Excretory System

The function of the excretory system is to remove the waste products that the body produces which are harmful to us.

Understanding Blood Pressure

Blood pressure is generated by the heart and is needed to keep the blood flowing. The value for a healthy person with normal pressure should be 120 over 80 mmHg (millimeters of mercury).

• The first number is the higher pressure caused as the left ventricle contracts to push blood out of the heart.
• The lower value is the pressure in the arteries during the time that the heart is filling with blood.

What is Hypertension?

Hypertension occurs when a resting person's blood pressure is higher than about 140/90 mmHg.

Causes and Risk Factors

It can be genetic, but you can also develop...

The Evolution of Eukaryotic Cells

The evolution from prokaryotic to eukaryotic cells began with a series of changes.

Loss of the Cell Wall

The resulting cell possessed a single, flexible membrane containing many ribosomes, which serve to synthesize digestive enzymes.

The convolution of the cell membrane allowed the cell to increase in size through folds, providing a larger surface area for nutrient absorption. Subsequently, digestive enzymes break down material, which is then expelled from the cell.

Formation of the Nucleus

Digestion occurs both inside and outside the cell. The membrane invaginates to enclose the DNA, creating a precursor to the cell nucleus.

Development of Organelles

The first structures to appear were peroxisome precursors, which...