Homeostasis

Which of the following is an example of positive feedback?

• Thermoregulation

• Blood Pressure

• Childbirth

• Blood Sugar Levels

Homeostasis

• allows for a wildly fluctuating internal environment
• is impossible in vertebrates
• is the maintenance of a relatively stable internal environment and often incorporates a form of feedback regulation
• is the maintenance of a relatively stable external environment and often incorporates a form of feedback regulation

When you get cut, your skin cells release hormones that signal platelets to come and stop the bleeding. Platelets then release more hormones that signal even more platelets to help stop bleeding. The hormone signals continue until the cut is closed.

• Positive Feedback Response
• Negative Feedback Loop 

Rapid growth during puberty causes your body to release more and more growth hormones. As you grow, more and more growth hormones are released until puberty is reached, and then the hormones stop.

• Positive Feedback Response
• Negative Feedback Loop 

Stomata are made of specialized cells called ______ which surround a tiny pore/opening

• stoma

• guard cells

• dermal cells

• diffusion channels

Stomata are made of specialized cells called ______ which surround a tiny pore/opening

• stoma

• guard cells

• dermal cells

• diffusion channels

The main function of stomata is to

• capture sunlight

• protect leaves from insects

• allow gases to move rapidly in/out of leaves

• release sugars into the atmosphere

During times of higher temperatures

• leaves will have more open stomata

• leaves will have fewer open stomata

• there will not be any changes in the number of stomata

• there will be no stomata at all

Leaves will have the highest number of open stomata when

• temperatures are unusually high and CO2 levels are also high

• temperatures are low and CO2 levels are also low

• temps are high and CO2 levels are low

• temps are low and CO2 levels are high

What pore-like feature on a plant's leaves prevent water from escaping?

• Phloem

• Stomata

• Roots

• Xylem