Bio - Term 3 - non-infectious disease test

What is homeostasis?

The maintenance of a relatively stable internal environment despite changes in the external environment.

What things need to be maintained in humans for homeostasis?

Core body temperature, blood glucose levels, sodium and water balance in blood, pH of body fluids, blood pressure/volume.

What happens without homeostasis?

Cells cannot function at their optimum level, leading to disease and death.

In mammals, what is homeostasis controlled by?

The nervous and endocrine systems.

What do the nervous and endocrine systems do?

They detect changes in the environment and counteract the effects of those changes.

What is the nervous system made up of in mammals?

The central nervous system (brain and spinal cord) and the peripheral nervous system (branching nerves).

What do nerve fibres contain?

Many nerve cells (neurons) that transmit electrical impulses around the body.

What neurons detect changes (stimuli) in the environment?

Receptors such as thermoreceptors, photoreceptors, chemoreceptors, and osmoreceptors.

What happens after receptors detect a stimulus?

Electrical messages called neural pathways are sent to and from the CNS to initiate a response.

What are some common stimuli in the environment?

Bright light, heat/cold objects on skin, loud noise, odour, high-blood glucose.

What is the endocrine system?

A series of glands that secrete hormones acting as chemical messengers in homeostasis.

What is an example of a hormone involved in homeostasis?

Insulin, released by the pancreas to help maintain blood glucose levels.

What is a negative feedback loop?

A response that alters the effect of the original stimulus to maintain homeostasis.

What is an example of negative feedback in thermoregulation?

The nervous system maintains a constant core body temperature of 37°C despite external temperature changes.

What happens if core body temperature cannot be maintained?

Enzymes stop functioning, which may lead to death.

What are some responses in humans for warming external temperature?

Sweating, vasodilation, hair relaxing.

What are some responses in humans for cooling external temperature?

Shivering, vasoconstriction, hair erecting.

What is required by all cells for the process of cellular respiration?

Glucose.

What happens when blood sugar increases after eating?

The pancreas releases insulin.

What does insulin do?

It causes the liver to take up excess glucose and store it as glycogen.

What happens when blood sugar decreases after fasting?

The pancreas releases glucagon.

What does glucagon do?

It converts glycogen into glucose and releases it into the blood.

What does a person with diabetes deal with?

Their body does not produce insulin properly, impeding blood glucose control.

What happens in a positive feedback loop?

The response reinforces the effect of the stimulus.

What is an example of a positive feedback loop?

During childbirth, oxytocin is released to enhance contractions.

What are endotherms?

Animals that can maintain a constant internal temperature despite the ambient temperature.

How do endotherms maintain their temperature?

Through internal heat production.

What is a behavioral adaptation for temperature regulation?

Altering body position, such as huddling together for warmth.

What is an example of burrowing behavioral adaptation?

Species using burrows to escape extreme heat or cold.

What is nocturnal behavioral adaptation?

Active at night to conserve energy during high daytime temperatures.

What is migration behavioral adaptation?

Moving to areas that better suit temperature tolerance.

What is an example of insulation structural adaptation?

Thick fur or blubber in animals to retain body heat.

What do humpback whales migrate for?

To mate.

What is insulation in animals?

Fur, hair, and feathers trap air to reduce heat loss.

How does surface area to volume ratio affect heat loss?

Higher SA:Vol can lose heat more efficiently.

How are bilby ears adapted to their environment?

Large ears are suited for hot environments.

How are mountain pygmy possum ears adapted to their environment?

Small ears are suited for cold environments.

What is one way animals regulate blood flow?

By expanding or constricting capillaries.

What is evaporative cooling?

Sweating, panting, or licking body parts to remove heat.

What is hibernation?

An extended period of inactivity in response to cold.

What do plants need water for?

As a solvent for chemical processes like photosynthesis.

What can help cool plants in warm environments?

Increased water movement up the stem.

What happens to plants when it's warm?

They allow more water to move up the stem.

What are some mechanisms plants use to limit water loss?

Reduced leaf size- minimising SA and stomata exposed e.g. Hakea, Casurina. Leaf orientation - facing downwards to avoid direct exposure of sun to stomata e.g. Eucalyptus. Thick cuticles - outer layer that prevents excess water loss from outer leaf cells. Leaf rolling - roll leaves inwards so stomata face inwards away from sunlight e.g. Spinifex.

What are some other mechanisms?

Stomata control - only open stomata during cooler parts of the day to reduce water loss. Sunken stomata - creating small humid chamber that traps moisture and slows diffusion from leaf. Water storage - succulents can store water in stems or leaves to retain moisture e.g. pigface.

What is disease defined as?

Any condition that impairs the proper functioning of a living thing.

Who can experience disease?

Most species of organisms, even bacteria.

What has developed throughout history regarding diseases?

Our understanding of the causes and treatments.

What are the two types of diseases?

Infectious (caused by pathogens) and non-infectious (not caused by pathogens).

What are examples of non-infectious diseases?

Environmental exposure, nutritional diseases, genetic diseases, cancer.

What is Kwashiorkor?

A condition caused by a severe lack of protein in the diet.

When can anemia occur?

Due to a deficiency of iron in the diet.

What is a genetic disease?

A disease caused by the inheritance of mutated genes.

What is an example of a genetic disease?

Sickle cell anemia.

What happens when tumor suppressor genes are mutated?

Uncontrolled cell division can occur, leading to tumors.

What is cancer?

When abnormal cells divide uncontrollably.

What is the mortality rate?

The proportion of the whole population expected to die from a disease.

What is fatality rate?

The proportion of the people with the disease expected to die.

What are some risk factors associated with cancer?

Smoking, alcohol consumption, obesity, exposure to radiation.

What is the incidence of a disease?

The number of new cases of a disease.

What is prevalence?

The proportion of a population that has the disease at a specific time.

Why is knowledge of disease data important?

It helps determine treatment methods and pathways for future research.