TExES Life Science 7-12 > Regulation & Homeostasis in Organisms > Flashcards

Regulation & Homeostasis in Organisms Flashcards

Understand how organisms regulate internal conditions using feedback mechanisms, hormones, and behaviors to maintain homeostasis. (60 cards)

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1
Q

How does the pancreas regulate blood glucose levels?

A

It secretes insulin when blood glucose levels are too high and glucagon when levels are too low.

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2
Q

What disease is attributed to a dysfunction of the pancreas resulting in a lack of insulin production and secretion?

A

Type 1 diabetes mellitus

Autoimmune destruction of pancreatic β cells leads to little or no insulin production.

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3
Q

What is chemical regulation?

A

Chemical regulation is control of body functions via chemical messengers (hormones/neurotransmitters).

E.g., insulin lowers blood glucose.

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4
Q

What is acidity and how is it measured?

A

Acidity is a measure of pH, ranging from 0 (highly acidic) to 14 (highly basic), with 7 being neutral.

The human body must maintain a pH range of 7.35 to 7.45 for proper function.

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5
Q

How does the body regulate pH?

A

By releasing chemicals to adjust pH and regulating breathing to control carbon dioxide levels.

Fast breathing can decrease acidity by expelling carbon dioxide, while slow breathing can increase acidity.

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6
Q

What are the consequences of the human body falling out of the pH range?

A

It can lead to severe health issues or death.

Maintaining the correct pH is vital for protein and enzyme function in the bloodstream.

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7
Q

Define:

phototropism

A

It is growth in response to directional light.

Shoots usually grow toward light = positive phototropism; roots may show negative phototropism.

This growth helps plants access necessary resources for energy.

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8
Q

Define:

halophyte

A

A plant that can grow in saline conditions, like Acrostichum aureum.

These plants maintain homeostasis in salty environments where other plants cannot survive.

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9
Q

What is a feedback loop in homeostasis?

A

A control process where receptors detect change, a control center compares to a set point, and effectors adjust the variable via negative or positive feedback.

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10
Q

What are the two main types of feedback loops?

A
  • Positive feedback loops
  • Negative feedback loops
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11
Q

What occurs in a positive feedback loop?

A

The product of the effector stimulates the effector and increases the product.

A change triggers responses that amplify that change (self-reinforcing), e.g., oxytocin increases uterine contractions during childbirth.

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12
Q

What occurs in a negative feedback loop?

A

The original state is restored due to a response that opposes the change.

Example: Your body will respond to cold temperatures by restricting blood flow to extremities as well as causing goosebumps and shivering. Once your body is back to a normal temperature the goosebumps go away, normal blood flow is restored and shivering stops.

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13
Q

What is homeostasis?

A

The steady state of internal conditions maintained by an organism despite a changing environment.

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14
Q

What are the three main systems of homeostasis in body systems?

A
  • Thermoregulation
  • Osmoregulation
  • Chemical regulation
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15
Q

What are the main body systems for maintaining homeostasis?

A

Endocrine and Nervous systems

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16
Q

What is the main organ system acting as a sensor in homeostasis?

A

nervous system

The nervous system includes cells called neurons containing receptors that sense changes in the environment.

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17
Q

What are the effectors in homeostasis?

A

Organs that carry out processes to maintain homeostasis, controlled by the endocrine and nervous systems.

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18
Q

How does antidiuretic hormone help maintain homeostasis?

A

It promotes the reabsorption of water from the kidneys.

By increasing the reabsorption of water, blood pressure as well as salt content in the body can stay in homeostasis.

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19
Q

How does a fever initiated by an immune response help your body reach homeostasis?

A

The fever will kill any pathogens causing the immune response. Once the pathogens have been eliminated the body will return to homeostasis.

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20
Q

What is the goal of homeostasis?

A

To maintain a steady internal environment.

This involves various methods and mechanisms in the body.

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21
Q

What can happen if homeostasis mechanisms fail?

A

Life-changing diseases may occur, such as type 1 diabetes.

Individuals with type 1 diabetes must inject insulin daily.

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22
Q

What are some key parameters humans maintain for homeostasis?

A
  • Salinity
  • Temperature
  • Blood glucose
  • Sex hormones
  • Hormones involved in sleep, mood, and motivation
  • Water excretion and retention
  • Blood volume

These parameters are critical for maintaining life.

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23
Q

How is the term ‘homeostasis’ applied outside of biology?

A

It describes processes in social sciences and economics that work towards an ideal level.

For example, emotional homeostasis in psychology and supply-demand balance in economics.

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24
Q

List the biological control mechanisms animals use to maintain homeostasis.

A
  • Metabolism
  • Temperature
  • Waste Presence
  • pH or Acidity
  • Water Levels
  • Salt
  • Electrolyte Levels

These mechanisms work together to keep the internal environment of the organism stable.

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25
Why is it important for organisms to **maintain homeostasis**?
**To keep internal mechanisms and functions alive**; falling out of homeostasis can lead to illness or death. ## Footnote For example, humans regulate temperature through sweating to prevent overheating.
26
# Fill in the blank: Homeostasis is especially important for \_\_\_\_\_\_\_ living things because they cannot move to improve their circumstances.
sessile
27
What are the five examples of **homeostasis in plants**?
* Water balance * Oxygen balance * Carbon dioxide balance * Temperature balance * Nutrient balance ## Footnote These factors are crucial for plant survival and growth.
28
What is **metabolism**?
The biomechanism that comprises **all chemical reactions** within the cells of a living organism. ## Footnote Metabolism provides energy and contributes to the synthesis of necessary biochemicals.
29
Explain the law of conservation of energy.
Energy can **neither be created nor destroyed**; it can only change forms, move, or escape systems. ## Footnote This principle applies to how organisms utilize and store energy from food.
30
What happens to an organism's metabolism when it is **starving**?
The metabolism slows down to **conserve fat**. ## Footnote This adaptive mechanism helps the organism survive during periods of energy scarcity.
31
What stimuli are **perceived** by your nervous system?
* Visual (sight) * Auditory (sound) * Tactile (touch) * Olfactory (smell) * Gustatory (taste)
32
What is the role of the **control center** in homeostasis?
It **compares a receptor's message** to a set point and signals effectors to make changes. ## Footnote The control center is part of the central nervous system.
33
# Define: osmoregulation
The maintenance of the **body's salt and water balance** in homeostasis. ## Footnote Freshwater fish gain water osmotically, excrete large amounts of dilute urine, and actively absorb ions via gill ion pumps (chloride cells).
34
How do **freshwater fish** maintain osmoregulation?
They **passively consume water** from their environment and **capture salts** through their **gills**. ## Footnote This process contrasts with marine fish and land animals, which must actively seek water.
35
Provide an example of **homeostasis** related to **water levels**.
An animal consumes fresh water in its environment to **increase** its water levels. ## Footnote This is a direct mechanism for osmoregulation in various organisms.
36
What organ secretes **antidiuretic hormone**?
Pituitary gland
37
How does the body **cool** itself when it becomes too hot?
By sending signals to start **sweating**, which cools the body as sweat evaporates. ## Footnote This is an example of a negative feedback loop.
38
# Define: heliotropism
The ability of a plant to **follow the sun's movement** across the sky. ## Footnote An example is the sunflower, which increases light absorption by about 10%.
39
# Define: nastic movement
Movements made by plants that are **not directional**, like the closing of a Venus flytrap's lobes. ## Footnote These movements are typically temporary and not related to growth direction.
40
What is a **Lazarus** plant?
A plant that can **survive extreme droughts** and appears dead but revives with water, such as X. viscosa. ## Footnote Research is ongoing to understand the mechanisms behind these resurrection capabilities.
41
What are **stomata**?
Tiny **openings** in plant leaves that **regulate gas exchange** and transpiration. ## Footnote The plural for stoma is either stoma or stomata.
42
What is **transpiration**?
The process of water **evaporating** from the plant, resulting in **water loss**. ## Footnote It is essential for regulating H2O, CO2, and O2 levels within the plant.
43
What is **turgor pressure**?
The **pressure** within plant cells caused by the correct amount of water in vacuoles. ## Footnote Limp plants experience low turgor pressure, often due to water deficiency.
44
What characterizes a **diurnal sleep pattern**?
Active and **awake during the day** and sleep at night. ## Footnote Organisms with diurnal sleep patterns: Humans, primates, and some birds.
45
What characterizes a **nocturnal sleep pattern**?
Animals **sleep during the day** and are active at night. ## Footnote Organisms with nocturnal sleep patterns: Coyote, Leopard, Hippopotamus.
46
What characterizes the **hibernation** sleep pattern?
**A state of suspended animation**, often used as an alternative to migration during seasons of difficult weather, like a cold winter. ## Footnote Organisms that exhibit hibernation include bears, bees, groundhogs.
47
What characterizes a **basking sleep pattern**?
Cold-blooded animals **can't regulate their body temperatures**, so they seek heat from an outside source, like the sun. ## Footnote Examples of organisms that will bask to control their body temperature include lizards, turtles, and snakes.
48
What is the **center in the brain** that takes cues from the environment about determining the optimal times for sleep?
Suprachiasmatic nucleus | (SCN)
49
What are the **4 common types** of sleep patterns in organisms?
* Diurnal * Nocturnal * Hibernation * Basking
50
How does **sleep** help the body to maintain homeostasis?
* Allowing the body time to regulate hormones. * Allow time to regulate blood pressure and reduce inflammation. * Allow time for the production of white blood cells that aid in immunity.
51
What are the **benefits** of a hibernation sleep pattern?
* Protection from harsh conditions * Energy conservation * Reduced risk of predation
52
What is **thermoregulation**?
The process of **regulating body temperature** (in humans) to maintain a core temperature of ~37 degrees Celsius. ## Footnote The role of temperature regulation in homeostasis maintains a stable body temperature, preventing conditions like hypothermia or fever.
53
How does the body **regulate temperature**?
Through a **negative feedback loop** controlled by the **hypothalamus** in the brain, causing changes like sweating and dilating blood vessels to release excess heat.
54
What is the role of the **hypothalamus** in regulating body temperature?
It processes **sensory information** and causes changes in effector organs to decrease or increase temperature.
55
What are **animals** called that **cannot regulate** their body temperature?
Ectotherms ## Footnote Also known as being cold-blooded. Examples: Lizard, snakes, turtles.
56
What are **animals** called that **can regulate** their body temperature?
Endotherms ## Footnote Also known as being warm-blooded. Examples: Humans, dogs, birds.
57
# Fill in the blank: The human body can only vary by \_\_\_ degrees Fahrenheit before reaching dangerous temperatures.
2 ## Footnote This narrow range is critical for preventing hypothermia and fever.
58
What is thermoregulation in **plants**?
Via **transpiration**, **leaf orientation**, and **heat-shock** responses to prevent overheating or freezing. ## Footnote This process is still being researched, as the biochemical mechanisms are not fully understood.
59
What happens to plants in **extremely cold** temperatures?
They can go **dormant**, stopping active growth to survive long winters. ## Footnote Some plants prepare by killing off leaves and storing nutrients in their core.
60
What **distinguishes** endotherms from ectotherms?
**Endotherms** produce their own heat, while **ectotherms** depend on environmental factors. ## Footnote Many endotherms (e.g., mammals, birds) are homeothermic, but endothermy and homeothermy are distinct concepts.
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