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

Fundamentals of Living Things and Environment

Composition of Living Matter

Living things are primarily composed of carbon, oxygen, hydrogen, and nitrogen. These elements constitute organic matter.

Essential Life Functions

Living things perform three main functions:

• Nutrition
• Interaction
• Reproduction

Conditions Necessary for Life

The fundamental conditions required for life include:

1. Liquid water
2. A magnetic field
3. A protective atmosphere
4. Carbon compounds
5. An energy source

Environmental Factors

Abiotic Factors

These are the environmental and physical conditions that influence where organisms can live.

Biotic Factors

These encompass the living things within an environment and the interactions between them.

Ecosystem Components

Biotope

This is the non-living part of an...

Human Circulatory System: Double Circulation

The human circulatory system performs double circulation, meaning that the blood passes through the heart twice in order to complete a full circuit. The two loops are completely separate from one another, which prevents the mixing of deoxygenated blood.

• Blood passes through the lungs.
• All the organs receive blood that is equally rich in oxygen and nutrients.

Right Half of the Heart

• Vena cavae carry blood back to the heart.
• Blood enters through the right atrium and moves to the right ventricle.
• Blood exits through the pulmonary artery and goes to the lungs.

Left Half of the Heart

• Pulmonary veins bring blood from the lungs to the heart.
• Blood enters through the left atrium and moves to the left ventricle.
• Blood

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Sexual Reproduction & Meiosis

Sexual Reproduction: Takes place when two sex cells, or gametes, from two parents of different sexes join together.

Meiosis: A cell division process through which haploid cells are formed.

Fundamental Genetic Concepts

• Traits: Each of the characteristics present in an organism that can be inherited by its offspring.
• Gene: A section of DNA that contains information about a certain trait and controls that trait.
• Alleles: Different forms of a gene.
• Homozygous: When two alleles for a specific trait are identical (e.g., AA, aa).
• Heterozygous: When two alleles for a specific trait are different (e.g., Aa).
• Genotype: An organism's complete set of genes.
• Phenotype: The observable way in which a genotype is expressed under specific

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Plant Nutrition

Photosynthesis: The process by which plants manufacture carbohydrates from raw materials using energy from light.

Key Aspects of Photosynthesis and Respiration

• Chlorophyll: Transfers light energy into chemical energy stored in molecules, essential for the synthesis of carbohydrates.
• Carbohydrate Use and Storage: Aside from using complex carbohydrates to create the plant's structure, plants store carbohydrates or use them for energy to grow.
• Respiration: To utilize stored carbohydrates, plants take the glucose formed during photosynthesis and combine the carbohydrate with oxygen—a process called respiration—to release energy.
• Role of Chlorophyll and CO₂: Chlorophyll is required because it helps absorb the light needed for photosynthesis.

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Photosynthesis

Photosynthesis is the fundamental process by which plants manufacture carbohydrates from raw materials using energy from light.

The Process of Photosynthesis

• Green plants take in CO2 through their leaves via diffusion.
• Water is absorbed through the plant's roots by osmosis and transported to the leaves through xylem vessels (moving upwards).
• Chloroplasts containing chlorophyll are responsible for trapping light energy. This energy is used to break up water molecules and then to bond hydrogen and CO2 to form glucose.
• Glucose is usually changed to sucrose for transport around the plant or to starch for storage.
• Oxygen is released as a waste product or used by the plant for respiration.

Factors Limiting Photosynthesis

Three factors can limit...

Sensory Cells and Structures

Rod Cells

Detect light intensity and are used in black and white vision.

Cone Cells

Detect color.

Hair Cells

Located in the inner ear, these contain mechanoreceptors that detect vibrations.

Cochlea

A structure of fluid-filled canals in the inner ear where hair cells are located.

The Nervous System: Divisions and Functions

Central Nervous System (CNS)

Comprises the brain and spinal cord.

Peripheral Nervous System (PNS)

A collection of nerves that connects the CNS to all organ systems.

Somatic Nervous System

A division of the PNS that regulates all movements over which you have voluntary control, connecting the CNS to target organs.

Autonomic Nervous System

A division of the PNS that controls automatic functions that do not...

TRIMS 2

• 1) Which term describes an animal? All of the above
• 2) Swiss scientist who first described and named organisms with binomial nomenclature: Gaspard Bauhin
• 3) Developed a two-name system: Carl Linnaeus
• 4) Characteristics that appear in recent parts of a lineage but not in older members: Derived character
• 5) Classification based on common ancestry: Cladistics
• 6) Molecules that use mutation rates to study evolution: mtRNA
• 7) American ecologist who classified a fifth kingdom: Fungi
• 8) Discovered two genetically different groups: rRNA
• 9) Thick cell wall without outer membranes: Gram-positive
• 10) Which are insects? Beetles, roaches, termites
• 12) What are jellyfish? All of the above
• 13) Taenia, Toxocara, annelids first opening: Mouth
• 14) Soft, parasitic,

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Nerve Impulse

A stimulus occurs, sensory receptors detect the stimulus, sensory neurons receive the information and transmit it to the central nervous system (CNS). The CNS receives the information and a response is decided. Motor neurons transmit the response to the effectors, which carry out the response. The response is given through motor responses carried out by muscles and secretory responses carried out by glands.

Nervous System

The nervous system receives and transmits information rapidly through electrical impulses. Information is transmitted through sensory neurons and processed in the CNS.

Endocrine System

The endocrine system consists of glands that secrete hormones. These hormones are carried in the blood to the cells of the target...

Spontaneous Generation

Spontaneous generation proposes that life began from inanimate objects.

Oparin's Theory

Alexander Ivanovich Oparin developed this abiogenic theory.

1. Components of the atmosphere (methane, ammonia, hydrogen, and water vapor) reacted due to the energy of storms, solar radiation, and continuous volcanic eruptions, creating simple organic molecules.
2. The Earth cooled down, and intense rain produced primitive seas where organic molecules accumulated.
3. Organic molecules joined, creating bigger molecules; some of them were insulated from the water inside structures called coacervates.
4. Some of the coacervates developed molecules in their interior that were able to self-replicate; these were the first organisms and the origin of all cells.

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