Physiological Responses and Feedback Mechanisms

The video tutorial by Mr. Anderson covers the concept of homeostasis at various levels, including individual organisms, populations, and ecosystems. It explains feedback loops, both negative and positive, and their roles in maintaining stability. The tutorial also discusses behavioral and physiological responses to environmental changes, regulation mechanisms like blood glucose and thermoregulation, and the impact of biotic and abiotic factors. Evolutionary aspects of homeostasis, plant and animal defenses, and cell differentiation are also explored, highlighting how organisms sense and respond to their environment.

What is the primary characteristic of a negative feedback loop?

• It only occurs in non-living systems.

• It amplifies changes away from a set point.

• It maintains stability by counteracting changes.

• It is less common than positive feedback loops.

Which of the following is an example of a positive feedback loop?

• Maintaining blood glucose levels.

• Childbirth contractions increasing pressure.

• Shivering to increase body temperature.

• Sweating to cool down the body.

How do organisms typically respond behaviorally to cold temperatures?

• By reducing body size.

• By migrating to warmer areas.

• By changing skin color.

• By increasing metabolic rate.

What physiological response helps a runner cool down during a race?

• Vasoconstriction

• Vasodilation

• Increased heart rate

• Decreased breathing rate

What hormone is released when blood glucose levels rise?

• Cortisol

• Insulin

• Adrenaline

• Glucagon

Which organ is primarily responsible for osmoregulation in the body?

• Liver

• Heart

• Kidney

• Lungs

What is an example of a biotic factor affecting an ecosystem?

• Temperature changes

• Introduction of a new predator

• Soil pH levels

• Water salinity

How do plants typically defend themselves against pathogens?

• By secreting insulin

• By hardening cell walls

• By increasing body temperature

• By producing antibodies

What process involves the programmed death of cells?

• Apoptosis

• Differentiation

• Mitosis

• Photosynthesis

What mechanism explains the evolution of traits like photoperiodism in plants?

• Artificial selection

• Random mutation

• Natural selection

• Genetic drift