Regulation and Homeostasis in Organisms

Question 1

How does the pancreas regulate blood glucose levels?

Answer 1

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

Question 2

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

Answer 2

Diabetes

Question 3

What is chemical regulation?

Answer 3

The process of maintaining homeostasis of chemicals in the body.

Question 4

What is acidity and how is it measured?

Answer 4

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.

Question 5

How does the body regulate pH?

Answer 5

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.

Question 6

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

Answer 6

It can lead to severe health issues or death.

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

Question 7

Define:

phototropism

Answer 7

The growth of a plant toward better sunlight or away from harmful stimuli.

This growth helps plants access necessary resources for energy.

Question 8

Define:

halophyte

Answer 8

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

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

Question 9

What is a feedback loop in homeostasis?

Answer 9

A control loop where the product of the system regulates itself.

Question 10

What are the two main types of feedback loops?

Answer 10

• Positive feedback loops
• Negative feedback loops

Question 11

What occurs in a positive feedback loop?

Answer 11

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

Example: During childbirth when the baby’s head presses on the cervix, causing the release of oxytocin to promote further contractions. This continues until the baby is born.

Question 12

What occurs in a negative feedback loop?

Answer 12

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.

Question 13

What is homeostasis?

Answer 13

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

Question 14

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

Answer 14

• Thermoregulation
• Osmoregulation
• Chemical regulation

Question 15

What are the main body systems for maintaining homeostasis?

Answer 15

Endocrine and Nervous systems

Question 16

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

Answer 16

nervous system

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

Question 17

What are the effectors in homeostasis?

Answer 17

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

Question 18

How does antidiuretic hormone help maintain homeostasis?

Answer 18

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.

Question 19

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

Answer 19

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

Question 20

What is the goal of homeostasis?

Answer 20

To maintain a steady internal environment.

This involves various methods and mechanisms in the body.

Question 21

What can happen if homeostasis mechanisms fail?

Answer 21

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

Individuals with type 1 diabetes must inject insulin daily.

Question 22

What are some key parameters humans maintain for homeostasis?

Answer 22

• 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.

Question 23

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

Answer 23

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.

Question 24

List the biological control mechanisms animals use to maintain homeostasis.

Answer 24

• 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.

Question 25

Why is it important for organisms to **maintain homeostasis**?

Answer 25

**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.

Question 26

# Fill in the blank: Homeostasis is especially important for \_\_\_\_\_\_\_ living things because they cannot move to improve their circumstances.

Answer 26

sessile

Question 27

What are the five examples of **homeostasis in plants**?

Answer 27

* Water balance * Oxygen balance * Carbon dioxide balance * Temperature balance * Nutrient balance ## Footnote These factors are crucial for plant survival and growth.

Question 28

What is **metabolism**?

Answer 28

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.

Question 29

Explain the law of conservation of energy.

Answer 29

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.

Question 30

What happens to an organism's metabolism when it is **starving**?

Answer 30

The metabolism slows down to **conserve fat**. ## Footnote This adaptive mechanism helps the organism survive during periods of energy scarcity.

Question 31

What stimuli are **perceived** by your nervous system?

Answer 31

* Visual (sight) * Auditory (sound) * Tactile (touch) * Olfactory (smell) * Gustatory (taste)

Question 32

What is the role of the **control center** in homeostasis?

Answer 32

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.

Question 33

# Define: osmoregulation

Answer 33

The maintenance of the **body's salt and water balance** in homeostasis.

Question 34

How do **freshwater fish** maintain osmoregulation?

Answer 34

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.

Question 35

Provide an example of **homeostasis** related to **water levels**.

Answer 35

An animal consumes fresh water in its environment to **increase** its water levels. ## Footnote This is a direct mechanism for osmoregulation in various organisms.

Question 36

What organ secretes **antidiuretic hormone**?

Answer 36

Pituitary gland

Question 37

How does the body **cool** itself when it becomes too hot?

Answer 37

By sending signals to start **sweating**, which cools the body as sweat evaporates. ## Footnote This is an example of a negative feedback loop.

Question 38

# Define: heliotropism

Answer 38

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%.

Question 39

# Define: nastic movement

Answer 39

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.

Question 40

What is a Lazarus plant?

Answer 40

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.

Question 41

What are **stomata**?

Answer 41

Tiny **openings** in plant leaves that **regulate gas exchange** and transpiration. ## Footnote The plural for stoma is either stoma or stomata.

Question 42

What is **transpiration**?

Answer 42

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.

Question 43

What is **turgor pressure**?

Answer 43

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.

Question 44

What characterizes a **diurnal sleep pattern**?

Answer 44

Active and **awake during the day** and sleep at night. ## Footnote Organisms with diurnal sleep patterns: Humans, primates, and some birds.

Question 45

What characterizes a **nocturnal sleep pattern**?

Answer 45

Animals **sleep during the day** and are active at night. ## Footnote Organisms with nocturnal sleep patterns: Coyote, Leopard, Hippopotamus.

Question 46

What characterizes the **hibernation** sleep pattern?

Answer 46

**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.

Question 47

What characterizes a **basking sleep pattern**?

Answer 47

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.

Question 48

What is the **center in the brain** that takes cues from the environment about determining the optimal times for sleep?

Answer 48

Suprachiasmatic nucleus | (SCN)

Question 49

What are the **4 common types** of sleep patterns in organisms?

Answer 49

* Diurnal * Nocturnal * Hibernation * Basking

Question 50

How does sleep help the body to maintain homeostasis?

Answer 50

* 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.

Question 51

What are the **benefits** of a hibernation sleep pattern?

Answer 51

* Protection from harsh conditions * Energy conservation * Reduced risk of predation

Question 52

What is **thermoregulation**?

Answer 52

The process of **regulating body temperature** 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.

Question 53

How does the body **regulate temperature**?

Answer 53

Through a **negative feedback loop** controlled by the **hypothalamus** in the brain, causing changes like sweating and dilating blood vessels to release excess heat.

Question 54

What is the role of the **hypothalamus** in regulating body temperature?

Answer 54

It processes **sensory information** and causes changes in effector organs to decrease or increase temperature.

Question 55

What are **animals** called that **cannot regulate** their body temperature?

Answer 55

Ectotherms ## Footnote Also known as being cold-blooded. Examples: Lizard, snakes, turtles.

Question 56

What are **animals** called that **can regulate** their body temperature?

Answer 56

Endotherms ## Footnote Also known as being warm-blooded. Examples: Humans, dogs, birds.

Question 57

# Fill in the blank: The human body can only vary by \_\_\_ degrees Fahrenheit before reaching dangerous temperatures.

Answer 57

2 ## Footnote This narrow range is critical for preventing hypothermia and fever.

Question 58

What is thermoregulation in **plants**?

Answer 58

The maintenance of temperature homeostasis. ## Footnote This process is still being researched, as the biochemical mechanisms are not fully understood.

Question 59

What happens to plants in **extremely cold** temperatures?

Answer 59

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.

Question 60

What **distinguishes** endotherms from ectotherms?

Answer 60

**Endotherms** produce their own heat, while **ectotherms** depend on environmental factors. ## Footnote Endotherms are also referred to as homeotherms.