Homeostasis and Systems Topic #2

What is the role of neurotransmitter signals in the nervous system?

• They are secreted by glands.

• They are taken up by receptors on the dendrite end of a nerve.

• They regulate blood glucose levels.

• They act as a barrier in the immune system.

Answer explanation

Neurotransmitter signals are crucial in the nervous system as they are taken up by receptors on the dendrite end of a nerve, facilitating communication between neurons and enabling various functions such as movement and sensation.

What is the function of hormones in the endocrine system?

• They act as a barrier against pathogens.

• They speed up chemical reactions.

• They are used to break down proteins.

• They are secreted from glands and taken up by cell membrane receptors.

Answer explanation

Hormones are chemical messengers secreted by glands in the endocrine system. They travel through the bloodstream and bind to specific receptors on cell membranes, triggering various physiological responses.

Tags

NGSS.HS-LS1-3

What is dynamic equilibrium also known as?

• Negative feedback

• Antibiotic resistance

• Homeostasis

• Immunity

Answer explanation

Dynamic equilibrium is often referred to as homeostasis, which describes the stable internal conditions maintained by living organisms despite external changes.

Tags

NGSS.HS-LS1-3

What happens during negative feedback?

• The body produces antibodies to fight bacteria.

• The immune system attacks foreign pathogens.

• The body secretes hormones to increase blood glucose levels.

• A stimulus triggers a response that returns the body to its steady (normal) state.

Answer explanation

Negative feedback occurs when a stimulus triggers a response that counteracts the initial change, helping to restore the body to its normal state. This is crucial for maintaining homeostasis.

Tags

NGSS.HS-LS1-3

What is the primary function of enzymes?

• To secrete hormones

• To act as a catalyst to speed up chemical reactions

• To transport materials around the cell

• To act as a barrier in the immune system

Answer explanation

The primary function of enzymes is to act as catalysts, which means they speed up chemical reactions in the body without being consumed in the process. This is essential for various biological functions.

What can affect enzyme reaction rates?

• Antibody production

• Blood glucose levels

• Temperature, pH, and salinity

• Hormone secretion

Answer explanation

Enzyme reaction rates are influenced by temperature, pH, and salinity, as these factors affect enzyme structure and activity. Antibody production, blood glucose levels, and hormone secretion do not directly impact enzyme kinetics.

What is the role of white blood cells in the immune system?

• To secrete insulin

• To attack pathogens

• To regulate body temperature

• To transport oxygen

Answer explanation

White blood cells play a crucial role in the immune system by attacking pathogens, such as bacteria and viruses, to protect the body from infections. This makes 'to attack pathogens' the correct answer.

What is an antigen?

• A type of enzyme

• A neurotransmitter signal

• A hormone secreted by glands

• A protein tag on pathogens recognized as foreign by the immune system

Answer explanation

An antigen is a protein tag found on pathogens that the immune system recognizes as foreign. This recognition triggers an immune response, distinguishing between self and non-self entities.

What is the function of antibodies?

• To transport materials around the cell

• To fit over antigens and block pathogen communication and reproduction

• To secrete hormones

• To break down proteins

Answer explanation

Antibodies function by binding to specific antigens on pathogens, effectively blocking their ability to communicate and reproduce, which helps the immune system neutralize infections.

What is immunity?

• The ability to fight off disease

• The process of breaking down food

• The secretion of hormones

• The movement of materials around the cell

Answer explanation

Immunity refers to the body's ability to fight off disease-causing pathogens. It involves various biological processes that protect against infections, making 'the ability to fight off disease' the correct choice.

Tags

NGSS.MS-LS1-3