Yr 9 Science Biology

What are the five types of receptors in the human body and what stimuli do they detect?

The five types of receptors include photoreceptors (light), mechanoreceptors (pressure, touch), thermoreceptors (temperature), chemoreceptors (chemicals), and nociceptors (pain).

What are the main parts of a typical neuron?

A typical neuron consists of the axon, dendrite, cell body, nucleus, myelin sheath, and synaptic terminal.

What is the function of the axon in a neuron?

The axon transmits electrical impulses away from the cell body.

What is the role of dendrites in a neuron?

Dendrites receive signals from other neurons and convey this information to the cell body.

What is the function of the myelin sheath?

The myelin sheath insulates the axon to increase the speed of electrical impulses.

What are the three types of neurons and what are their functions?

Sensory neurons receive stimuli from the environment, motor neurons send signals to muscles, and interneurons transmit signals between sensory and motor neurons.

How does a neuron transmit information around the body?

Neurons transmit information through the generation and propagation of electrical impulses along the axon and chemical signals at synapses.

What is the difference between a stimulus and a response?

A stimulus is an external factor that triggers a sensory receptor, while a response is the reaction of an organism to the stimulus.

Why are different parts of the skin more or less sensitive to touch?

Sensitivity varies based on the concentration of touch receptors, with areas like fingertips having a higher density of receptors.

What is the stimulus-response model?

The stimulus-response model is a framework that describes how stimuli are detected by receptors, processed by a control center, and result in a response from effectors.

What role do neurons play in the stimulus-response model?

Neurons transmit information from receptors to the control center and from the control center to effectors.

What is a reflex action?

A reflex action is an automatic response to a stimulus that does not require conscious thought, such as pulling your hand back from a hot surface.

What are the major parts of the Central Nervous System (CNS) and Peripheral Nervous System (PNS)?

The CNS consists of the brain and spinal cord, while the PNS includes somatic and autonomic divisions that connect the CNS to the body.

What are the major lobes of the brain?

The major lobes of the brain are the frontal lobe (decision-making), parietal lobe (sensory processing), temporal lobe (hearing and memory), and occipital lobe (vision).

Define the endocrine system.

The endocrine system is a network of glands that produce hormones to regulate various body functions.

What is the role of hormones in the body?

Hormones serve as chemical messengers that coordinate and regulate bodily functions.

What is the

How does the endocrine system respond during a 'Fight or Flight' situation?

During a 'Fight or Flight' situation, the endocrine system releases adrenaline and other hormones to prepare the body for quick action.

How do hormones maintain homeostasis?

Hormones maintain homeostasis through feedback mechanisms, such as insulin regulating blood sugar levels.

What is glucose's role in cellular respiration?

Glucose is the primary energy source for cells, providing fuel for cellular respiration.

How does the pancreas detect changes in blood sugar levels?

The pancreas detects changes through specialized cells called alpha and beta cells that monitor glucose concentrations.

How does insulin lower blood sugar levels?

Insulin facilitates the uptake of glucose by cells, lowering blood sugar levels.

Describe the negative feedback system in blood sugar regulation.

When blood sugar rises, insulin is released to lower it, and when it drops, glucagon is released to raise it.

What role does the liver play in glucose storage and release?

The liver stores glucose as glycogen and releases it into the bloodstream when blood sugar levels are low.

What are the symptoms of hyperglycemia and hypoglycemia?

Symptoms of hyperglycemia include increased thirst and urination, while hypoglycemia can cause shakiness, confusion, and sweating.

Define pathogen and disease.

A pathogen is a microorganism that can cause disease, while disease is a condition that results from the body's inability to function normally due to infection or other factors.

What is the role of the immune system?

The immune system protects the body against pathogens by identifying and attacking harmful microorganisms.

What are the three lines of defense in the immune system?

The three lines of defense are physical barriers (skin), innate immune responses, and adaptive immune responses.

What is the difference between natural and acquired immunity?

Natural immunity is immunity gained through exposure to pathogens, while acquired immunity is developed through vaccination or previous infection.

How do vaccinations provide immunity?

Vaccinations introduce a harmless form of a pathogen to stimulate the immune system to create a response and memory against future infections.

How can allergies stimulate an immune response?

Allergies occur when the immune system mistakenly identifies a harmless substance as a threat and mounts an inappropriate response.

Compare rheumatoid arthritis and type 1 diabetes as autoimmune diseases.

Rheumatoid arthritis causes joint inflammation and pain, while type 1 diabetes attacks insulin-producing cells in the pancreas.

Why is COVID-19 classified as a pandemic?

COVID-19 is classified as a pandemic due to its widespread transmission across multiple countries affecting a large number of people.

How is COVID-19 transmitted?

COVID-19 is transmitted through respiratory droplets and contact with contaminated surfaces (fomites) and can be mitigated by masks and hygiene practices.