Semester 1 Exam Review: Biology and Earth & Space

This set of vocabulary flashcards covers essential terms for Year 9 Science, focusing on the nervous system, immune system, endocrine system, plant reproduction, and Earth's cycles and spheres.

Infectious Diseases

Diseases that are caused by pathogens and can be spread from one organism to another.

Non-infectious Diseases

Diseases that are not caused by pathogens and cannot be spread between organisms.

Pathogens

Microbes such as viruses, bacteria, and fungi that cause disease.

Direct Contact

A mode of disease transmission involving physical touch between an infected individual and a susceptible host.

Indirect Contact

A mode of disease transmission where the pathogen is passed through intermediary means like the air or contaminated surfaces.

Negative Feedback Mechanism

A regulatory response, such as a fever or blood glucose control, where the body acts to reverse a change and return to a set point.

Axon

The long thread-like part of a nerve cell along which impulses are conducted from the cell body to other cells.

Myelin Sheath

An insulating layer that forms around nerves, allowing electrical impulses to transmit quickly and efficiently along the nerve cells.

Dendrite

A short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body.

Cell Body

The spherical part of the neuron that contains the nucleus and connects to the dendrites and axon.

Neurotransmitters

Chemical messengers that transmit signals across a chemical synapse from one neuron to another 'target' neuron.

Central Nervous System (CNS)

The part of the nervous system consisting of the brain and spinal cord.

Peripheral Nervous System (PNS)

The part of the nervous system that contains all the nerves that lie outside of the central nervous system.

Chemoreceptors

Sensory receptors that respond to chemical stimuli.

Mechanoreceptors

Sensory receptors that respond to mechanical pressure or distortion.

Pain Receptors

Sensory receptors that respond to potentially damaging stimuli by sending signals to the spinal cord and brain.

Photoreceptors

Sensory receptors that respond to light.

Thermoreceptors

Sensory receptors that respond to changes in temperature.

Reflex Response

An automatic and rapid motor response to a sensory stimulus.

Hormones

Chemical substances produced in the body that regulate the activity of certain cells or organs.

Homeostasis

The process by which biological systems maintain stability while adjusting to conditions optimal for survival.

Fragmentation

An asexual reproduction method where an organism breaks into several pieces, each of which grows into a new individual.

Budding

An asexual reproduction method where a new individual develops from a generative anatomical point of the parent organism.

Grafting

An asexual reproduction technique where tissues of plants are joined so as to continue their growth together.

Geosphere

The Earth's sphere that includes the rocks and minerals on Earth, from the crust to the core.

Biosphere

The Earth's sphere that encompasses all living organisms on the planet.

Hydrosphere

The Earth's sphere that includes all the water on the planet’s surface, underground, and in the air.

Atmosphere

The Earth's sphere consisting of the layers of gases surrounding the planet.

Combustion

The process of burning something, such as fossil fuels, which releases carbon into the atmosphere.

Photosynthesis

The process by which plants use sunlight to synthesize nutrients from carbon dioxide and water, acting as a carbon storage process.

Respiration

A process in living organisms involving the production of energy, typically with the intake of oxygen and the release of carbon dioxide.