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

Cell Biology: Key Processes and Concepts

Rough Endoplasmic Reticulum: An organelle responsible for protein synthesis and transport. Learn more about proteins.

Nucleolus: Responsible for the production and assembly of ribosomal components.

Ribosomes: Responsible for synthesizing proteins from genetic information transcribed from DNA in the form of Messenger RNA (mRNA).

Mitosis: The process of cell division by which the cell retains the genetic information contained in its chromosomes.

Meiosis: A type of cell division in sexually reproducing organisms.

Types of Cell Division

Sporulation, budding, pluripartition, and bipartition are all types of cell division.

Photosynthesis: A chemical process by which plants obtain their own food.

Carbohydrates: The...

1. Bacterial Antibodies

Which individual component of a bacterium should be injected into rabbits to generate effective antibodies against subsequent exposure to the same bacteria?
c. Bacterial chromosome DNA fragments

2. Lymphocytes

The lymphocyte, a type of leukocyte, is characterized by:
II. Providing long-term or short-term immunity to the body

3. Acquired Immunity

Acquired immunity, whether natural or artificial, is achieved by:
I. Suffering from an illness
II. Vaccination with an attenuated microbe
III. Administration of antibodies produced by another source

4. Natural Immunity

The term "natural immunity" refers to:
I. Immunity that develops during an individual's life as a result of the body's response to a pathogen
II. Immunity that is activated

Cytoplasm

The cytoplasm is located just after the plasma membrane. Its components are mostly water, which acts as a solvent, and proteins that function as enzymes.

Chloroplasts

Chloroplasts produce nutrients from the sun's radiant energy through photosynthesis. They have two membranes: an outer and an inner smooth one. The inner membrane has folds called lamellae, which are located in the grana.

Mitochondria

Mitochondria oxidize food through cellular respiration and store the released energy. They are surrounded by two membranes: a smooth external surface and internal folds or ridges.

Endoplasmic Reticulum

The endoplasmic reticulum has a membrane structure that connects easily with the membrane of the nucleus and has compartments called cisterns....

Key Ecological Concepts

Ecology is the science that studies the relationships between living beings, and also between them and their surrounding environment.

• Population: A group of individuals of the same species living together in a given area.
• Community: A group of populations living together in a specific area.
• Biotope: The physical environment or habitat occupied by a community.
• Ecosystem: The combination of the community and the biotope in which they live, including the ways in which individuals interact with one another and with their surrounding environment to reproduce and form a stable system.

Environmental Factors

The environment is influenced by various factors:

• Biotic factors: Factors that result from the presence and activities of other

The Human Digestive System: Key Organs and Functions

The Small Intestine

The small intestine is a vital part of the digestive system, measuring approximately 6.5 meters in length with a diameter of about 3 cm. It is highly convoluted and its interior walls are covered with numerous folds and microscopic projections called villi, significantly increasing its surface area for absorption. There are approximately 3,000 villi per square centimeter. The inner layer of the small intestine also contains intestinal glands that secrete digestive enzymes.

The small intestine is divided into three main sections:

• Duodenum: The first and shortest section, where most chemical digestion occurs as it receives digestive fluids from the pancreas and liver.
• Jejunum:

Stress and the Nervous System

In alarming situations, the nervous and hormonal systems trigger a series of processes that provoke reactions such as increased heart rate, elevated blood pressure, and heightened tension. This tension typically subsides when the alarming situation ends. However, if the situation persists, it can lead to anxiety, distress, depression, and insomnia.

To reduce these effects, consider the following:

• Adequate sleep
• Regular exercise
• Balanced diet
• Avoid consumption of tranquilizers, drugs, and sleep aids

Hormonal Coordination: The Endocrine System

The endocrine system is a set of glands formed by specialized cells that secrete hormones. Glands are classified as:

• Endocrine: Release hormones into the bloodstream.
• Exocrine: Discharge

Neck Muscles

Longus Colli

O: C3-C5, anterior tubercles of the transverse process; C5-T3, anterior surfaces of bodies; C2-C6, anterior surfaces
I: C2-C6 anterior surface
A: Laterally flexes head and neck, rotates head and neck towards the same side

Sternocleidomastoid

O: Mastoid process
I: 1/3 medial clavicular head
A: Flexes head and neck, laterally flexes head and neck, rotates head and neck to the opposite side

Longus Capitus

O: C3-C6
I: Occipital bone
A: Flexes head and trunk bilaterally

Rectus Capitus Anterior

O: C2 atlas
I: Occipital bone
A: Flexes head and neck

Splenius Capitus

O: Ligamentum nuchae
I: Temporal bone, mastoid process
A: Rotates head to the same side, extends head and neck

Splenius Cervicis

O: T3-T6 spinous processes
I: C2-C3 posterior tubercles
A:

Peripheral Nervous System

Consists of nerves and supports it collects info about the body's external and internal environment.

Central Nervous System

Consists of the brain and spinal cord, processes info, and creates a response.

Cell Body

The largest part of the typical neuron.

Dendrites

Short branched extensions that receive impulses from other neurons and carry them to the cell body.

Axon

Long fiber that carries impulses away from the cell body.

Myelin Sheath

Insulating membrane that surrounds a single, long axon.

Resting Potential

Electrical charge across the cell membrane of a resting neuron.

Action Potential

A nerve impulse that charges more negatively charged to more positively charged.

Threshold

The minimum level of a stimulus that is required to cause...

The Endocrine System

Hypothalamus: Produces releasing hormones, which control the activity of the pituitary gland.

Pineal Gland: Controls the daily sleep-wake cycle and produces melatonin.

Pituitary Gland: Directs the activity of other endocrine glands with a variety of hormones.

• Gonadotropic Hormones: Act on the sex organs.
• Oxytocin: Stimulates uterine contractions during childbirth.
• Growth Hormones: Control the elongation of bones.

Thyroid Gland: Regulates the body's overall metabolism with thyroxine. Produces calcitonin, which increases blood calcium levels.

Adrenal Glands: Regulate metabolism with cortisol, regulate kidney function with aldosterone, and prepare the organism for high-stress situations with adrenaline.

Pancreatic Islets: Control blood...

What are we made of?

Carbohydrates, Fats, Proteins, Water.

Metabolism:

All chemical reactions that take place inside the body.

Carbohydrates:

Include sugars and starches. Contain three types of atoms: carbon, hydrogen, oxygen.

Sugars: The simplest kind of carbohydrates are the simple sugars or monosaccharides, such as glucose and fructose. If two monosaccharides join, a disaccharide is formed.

Polysaccharides:
If many simple sugars join together, a molecule called a polysaccharide is made. (Starch and glycogen are polysaccharides.)

Carbohydrates Functions:
Energy: Energy is released by respiration. The carbohydrate used in respiration is usually glucose.
Transport: Animals transport glucose around the body, plants transport sucrose.
Storage: Plants store...