Unit 4 Test 2 Pt 1 Flashcards
What are feedback mechanisms?
Sensory pathways and responses that your body uses to maintain homeostasis.
Feedback mechanisms are essential for regulating various physiological processes.
What are the two types of feedback mechanisms?
- Negative Feedback
- Positive Feedback
These mechanisms play crucial roles in homeostatic regulation.
What does negative feedback do?
Slows down or stops a response.
Negative feedback is vital for maintaining stability in biological systems.
What does positive feedback do?
Amplifies or increases a response.
Positive feedback is often involved in processes that need a definitive outcome, such as childbirth.
What is an example of a stimulus in body temperature regulation?
Body temperature exceeds 37°C.
This triggers the feedback mechanism to restore normal temperature.
What type of sensors are involved in body temperature regulation?
Sensors like nerve cells with endings in the skin and brain.
These sensors detect changes in temperature and send signals to the control center.
What is the control center for body temperature regulation?
Temperature regulatory center in brain.
This center processes information from sensors and coordinates an appropriate response.
What is the effector in the negative feedback loop for body temperature regulation when the body becomes too hot?
Sweat glands throughout body.
Sweat glands help cool the body when temperature rises.
Fill in the blank: Negative feedback mechanisms tend to _______ a response.
[slow down or stop]
This action is crucial for maintaining homeostasis.
Fill in the blank: Positive feedback mechanisms tend to _______ a response.
[amplify or increase]
This is often seen in processes requiring a rapid change.
What is the function of negative feedback in physiological processes?
It regulates physiological processes by stopping a cellular response
This mechanism helps maintain homeostasis.
Give an example of negative feedback in the body.
Body temperature regulation through shivering and sweating
Shivering increases body temperature, while sweating decreases it.
What happens when body temperature increases in the context of negative feedback?
Stopping the response causes the body system to return to its normal state, a ‘set point’
This process helps to re-establish homeostasis.
True or False: Negative feedback mechanisms are responsible for initiating biological processes.
False
Positive feedback mechanisms are responsible for initiating and amplifying these processes.
Fill in the blank: Negative feedback mechanisms help to re-establish _______.
homeostasis
Homeostasis refers to the body’s ability to maintain a stable internal environment.
How can you describe negative feedback in simple terms?
Stopping something that makes homeostasis when it makes homeostasis/ you reach homeostasis
(You stop shivering when your body is warm enough again)
Positive feedback leads to another response but doesn’t lead to _____ while negative feedback does
Homeostasis
What is the role of insulin in blood glucose regulation?
Insulin stimulates the uptake of glucose by target cells, reducing blood glucose levels
Insulin is secreted by the pancreas in response to increased blood glucose.
What happens when blood glucose levels increase?
Stimulates secretion of insulin from the pancreas
This is part of the negative feedback mechanism that helps maintain homeostasis.
How does insulin affect target cells?
Causes them to increase uptake of glucose for use or storage
This process reduces the levels of glucose in the blood.
What occurs when insulin decreases blood glucose levels?
There is no longer a stimulus to release insulin
This illustrates the negative feedback loop in glucose regulation.
Fill in the blank: An increase in blood glucose typically stimulates secretion of _______.
[insulin]
True or False: Insulin increases blood glucose levels.
False
Insulin decreases blood glucose levels by facilitating glucose uptake.
What is the role of negative feedback in maintaining homeostasis?
Negative feedback helps to maintain homeostasis by counteracting changes in the body.
What stimulates the secretion of glucagon?
A decrease in blood glucose.
Where is glucagon secreted from?
Pancreatic cells.
What effect does glucagon have on target cells, especially in the liver?
It causes the release of glucose through glycogen breakdown.
What happens to blood glucose levels when glucagon acts on the liver?
Blood glucose levels increase.
What occurs when blood glucose levels increase?
There is no longer a stimulus to release glucagon.
What are insulin and glucagon classified as?
Counter-regulatory hormones
What is the primary effect of insulin on blood glucose levels?
Lowers glucose levels
What is the primary effect of glucagon on blood glucose levels?
Raises glucose levels
Insulin and glucagon have _______ effects on blood glucose levels.
Opposite
Which hormone is responsible for increasing blood glucose levels?
Glucagon
Which hormone is responsible for decreasing blood glucose levels?
Insulin
What is positive feedback?
A self-reinforcing process that amplifies responses
Positive feedback loops are mechanisms that enhance or amplify changes; this can lead to exponential growth or decline.
What gas do ripening fruits emit?
Ethylene gas
Ethylene is a plant hormone that regulates the ripening process in fruits.
What effect does ethylene gas have on nearby fruits?
Stimulates accelerated ripening
This phenomenon is an example of a positive feedback loop in plant biology.
True or False: Positive feedback mechanisms always lead to stability in biological systems.
False
Positive feedback can lead to instability and rapid changes in biological systems.
What is cell division in prokaryotes called?
Binary fission
What happens during binary fission in prokaryotic cells?
The prokaryotic cell elongates as the DNA replicates. A new cell membrane and cell wall are synthesized producing two daughter
This process is a form of asexual reproduction in prokaryotes.
True or False: Binary fission results in the creation of one daughter cell.
False
Binary fission produces two daughter cells.
What are the five steps of Binary fission?
What are the steps of mitosis?
What is the cell cycle simply?
Series of events an organisms cells grow and divide to form two genetically identical diploid daughter cells
What are the main phases of mitosis?
Interphase and M phase (mitosis) and cytokinesis
What are Quiescent cells?
Cells that are not divided but can enter the cell cycle when stimulated - these cells are also known as the G_0 phase (when cells aren’t in the cell cycle)
What is the G_0 phase in the cell cycle?
Non-dividing cells that can enter and leave the cell cycle based on environmental signals and cues.
Do all cells divide at the same rate?
No, not all cells divide at the same rate.
What determines how often cells divide?
How often they are ‘used’ or exposed to damaging conditions.
What is the total time of the cell cycle if it is 24 hours?
Interphase: 23/24 hrs and Mitosis (M Phase): 1/24 hrs.
Fill in the blank: Some cells don’t go through the _______.
cell cycle.
What do developing organisms require for growth?
Production of new cells that each possess a complete genome
This is essential for the organism to grow and develop properly.