Unit 4 Lesson 1: Homeostasis Portfolio 1

Question 1

Why do dogs pant more on hot days

Answer 1

Panting increases evaporation of water from the dog’s mouth and upper respiratory tract, which releases heat from the dog’s body.

Question 2

What happens when a person sweats

Answer 2

A similar process happens when a person sweats. When sweat forms on the skin, some of the moisture evaporates into the atmosphere, cooling down the skin.

Question 3

What does sweating and panting do to the body

Answer 3

Sweating and panting allow the body to maintain internal balance, or homeostasis.

Question 4

What is homeostasis

Answer 4

a state of internal balance maintained by living organisms

Question 5

All living things have systems that allow their body to maintain homeostasis. These systems respond to environmental stimuli. What is a stimulus

Answer 5

A stimulus is an action or process that causes change.

Question 6

Give an example of a stimulus

Answer 6

For example, the human body has an internal temperature of approximately 37 degrees Celsius. This temperature is needed for the stability of enzymes, which catalyze many important chemical reactions in our body. When the temperature in the environment rises, the body temperature rises and our skin starts to sweat. As sweat evaporates, it releases excess heat, which helps the body maintain a stable internal temperature.

Question 7

Stimulus: why do humans shiver

Answer 7

When it is really cold outside, the skeletal muscles of the human body start to shiver. These muscles involuntarily make small, fast, and repeated contractions, which generate heat. This helps the body maintain optimal temperature in cold weather.

Question 8

What does Homeostatis depend on

Answer 8

feedback mechanisms

Question 9

What is a feedback mechanism

Answer 9

A feedback mechanism is a system that responds positively or negatively to a stimulus.

Question 10

What is a positive feedback mechansim

Answer 10

A positive feedback mechanism is a system that moves in the direction of the stimulus.

Question 11

What is an example of a postivie feedback

Answer 11

An example of a positive feedback mechanism is the clotting of blood after the skin is wounded. When the skin is cut, the body secretes chemicals that stimulate platelets to form a clot at the wound site. A positive feedback mechanism continues this clot formation until the wound is sealed.

Question 12

What is anothe rexample of a psotive feedback desceibe plant repieing process

Answer 12

Another example of a positive feedback mechanism is the ripening of most fruits. When stimuli from the environment trigger a single fruit to ripen, that fruit gives off ethylene gas which sets off a positive feedback mechanism within the plant that triggers nearby fruit to ripen.

Question 13

What is negative feedback mechanism

Answer 13

The negative feedback mechanisms mitigate or reverse the effect of the stimuli.

Question 14

What kind of mechanism is controlling body temperature

Answer 14

Controlling body temperature is a negative feedback mechanism.

Question 15

What does the negative feedback mechanism do when the internal body temperature gets too high

Answer 15

When internal body temperature gets too high, the body triggers a negative feedback mechanism to cool the body.

Question 16

What does the negative feedback mechanism do when the internal body temperature gets too cold

Answer 16

When internal body temperature gets too cold, the body uses a different negative feedback mechanism to warm up the body.

Question 17

The thyroid gland secretes hormones that are crucial for growth, development, and metabolism. Thyroid-stimulating hormone (TSH) increases the amount of thyroid hormones the body releases. The model below shows the feedback mechanism that controls TSH release. Use this information and what you’ve learned about homeostasis to answer the questions.
Is this a positive or a negative feedback mechanism? Why?

Answer 17

It’s a negative feedback mechanism. When thyroid hormone levels are high, TSH production is reduced. This helps to maintain hormone levels in the body.

Question 18

The thyroid gland secretes hormones that are crucial for growth, development, and metabolism. Thyroid-stimulating hormone (TSH) increases the amount of thyroid hormones the body releases. The model below shows the feedback mechanism that controls TSH release. Use this information and what you’ve learned about homeostasis to answer the questions.
A person has low levels of thyroid hormones in the blood. Use the model to explain how the body would use this feedback mechanism to maintain homeostasis.

Answer 18

If thyroid hormone levels are low, more TSH will be produced. This will increase the release of thyroid hormones so that homeostasis is achieved.

Question 19

What are the two approaches to achiveing homeostatis

Answer 19

Confirmation and REgulation

Question 20

What is Conformation

Answer 20

Constant Physiological state is maintained becasue it conforms to the surroundings

Question 21

What is an example of conformation

Answer 21

The body temperature of Antartic Rock cod closely matches that of the surrounding seawater, -1.9 degress Celsius. The rock cod does not actively regulate its body temperature to math the seawarer. Instead, its body temperature remains constant becasue it conforms to the tempertaure of its surroundings

Question 22

What is regulation

Answer 22

REgulatory homeostasis is based on mechanisms that adjust the internal state to keep it within limits that can be tolerated, no matter what the surrounding (external) conditions are

Question 23

What is an example of regulaiton

Answer 23

A dog maintains a body temperature of 38 degress Celsius whether its hot or cold outside. If its body temperature tises, it might pant to cool off and maintain homeostatis. If body temperature falls, it might shiver to being its temperature back up to the target value

Question 24

Why is Homeostais importnat?

Answer 24

To keep Enzymes, Protein and Membrame Permeabilty funcioning normally

Question 25

Why is Homeostais importnat, enzumes wise ?

Answer 25

Most enzymes function best under a fairly narrrow range of condtions

Question 26

Why is Homeostais importnat proteins wise?

Answer 26

High temperatures and denature proteins, casuing them to lose their structure and thus ablity to funcion

Question 27

Why is Homeostais importnat membrane permeablity wise ?

Answer 27

temperature influences how solutes diffuse, In exterme cases, the expansion of water as it freezes can rip cells apart if the tissues drop below zero degress celsius.

Question 28

What do most animal do to ahvie homeostais? what are regulatory systems?

Answer 28

To ahvieve homeostatis, most animals have regulatory systems that constantly mointor internal conditions such as temperature, blood pressure, blood ph, and blood glucose. If one of those variables changes, the homeostatic system acts quickly yo modify it. Each of these systems has a set point

Question 29

What is a set point

Answer 29

A normal or target value for the controlled value

Question 30

What is another exmple of a postive feedback system

Answer 30

Oxytocin is a hormone that stimulates uterine contractions during labor. When labor begins, the pituitary gland secretes oxytocin. Oxytoxin helps induce contrations, which relaeases prostaglandins, which in turn triggers the release of more oxytoxcin. This cycle continues untill childbrith