3B4 Structure and Function of Animal Systems

Question 1

Define:

Homeostasis

Answer 1

The process of maintaining stable internal conditions.

It regulates factors like temperature, pH, and glucose to ensure proper functioning.

Question 2

Why is homeostasis important?

Answer 2

It ensures optimal conditions for cellular functions.

Maintaining stability allows processes like enzyme activity to occur efficiently.

Question 3

What is the body’s reaction to a stimulus called?

Answer 3

Response

Being able to respond to a stimulus helps organisms react to environmental changes, maintaining homeostasis or adapting to new conditions.

Question 4

True or False:

Negative feedback helps to restore balance in the body.

Answer 4

True

Negative feedback mechanisms are essential for maintaining homeostasis by reducing deviations from the set point.

Question 5

Fill in the blank:

The body maintains blood glucose levels through _________ feedback.

Answer 5

negative

The pancreas releases insulin to lower blood glucose and glucagon to raise it, maintaining a stable level in the blood.

Question 6

What is positive feedback?

Answer 6

A mechanism that amplifies a change.

It accelerates processes in the body. For example, childbirth involves a positive feedback loop of oxytocin and pressure that leads to more and more uterine contractions. This process continues until the baby is born.

Question 7

What is the primary difference between positive and negative feedback?

Answer 7

Negative feedback counteracts changes; positive feedback amplifies them.

Negative feedback maintains stability, while positive feedback accelerates processes.

Question 8

What is thermoregulation?

Answer 8

The regulation of body temperature.

It involves sweating, shivering, and adjusting blood flow to maintain stability.

Question 9

True or False:

Positive feedback maintains homeostasis.

Answer 9

False

Positive feedback amplifies changes, which doesn’t stabilize conditions.

Question 10

What do organs or cells that carry out responses called?

Answer 10

Effectors

Effectors perform actions like sweating or muscle contraction to restore homeostasis.

Question 11

What is the regulation of water and salt balance called?

Answer 11

Osmoregulation

It helps maintain fluid balance, which is essential for proper cell function.

Question 12

Fill in the blank:

Blood glucose levels are regulated by _________ feedback.

Answer 12

negative

Insulin and glucagon balance blood glucose levels through negative feedback.

Question 13

What happens when blood pressure drops?

Answer 13

Blood vessels constrict, and heart rate increases.

These responses help restore normal blood pressure.

Question 14

True or False:

Feedback mechanisms regulate blood pressure.

Answer 14

True

Negative feedback helps maintain stable blood pressure by adjusting heart rate and blood vessel diameter.

Question 15

What is the hypothalamus’ role in homeostasis?

Answer 15

It regulates temperature, hunger, and thirst.

The hypothalamus detects changes and activates appropriate responses to maintain stability.

Question 16

What happens if the body detects low blood oxygen?

Answer 16

Breathing rate increases.

This response helps bring in more oxygen to restore normal levels.

Question 17

True or False:

Negative feedback prevents drastic changes.

Answer 17

True

It reduces the impact of stimuli, helping maintain homeostasis.

Question 18

What is the function of the respiratory system?

Answer 18

To exchange oxygen and carbon dioxide between the body and environment.

The respiratory system includes organs like the lungs and the diaphragm, which facilitate gas exchange through breathing.

Question 19

What is the function of the alveoli in the lungs?

Answer 19

To exchange gases between the air and the blood.

The alveoli’s thin walls allow oxygen to diffuse into the blood and carbon dioxide to diffuse out.

Question 20

True or False:

The heart is part of the circulatory system.

Answer 20

True

The heart pumps blood through the circulatory system to distribute oxygen, nutrients, and waste.

Question 21

What is the role of red blood cells in the circulatory system?

Answer 21

To carry oxygen and carbon dioxide.

Red blood cells contain hemoglobin, which binds to oxygen and carbon dioxide, enabling efficient gas exchange.

Question 22

Fill in the blank:

The ________ system transports nutrients, gases, and waste products throughout the body.

Answer 22

circulatory

The circulatory system includes the heart, blood vessels, and blood, enabling transport within the body.

Question 23

What do neurotransmitters do?

Answer 23

They transmit signals between neurons.

Neurotransmitters are chemicals released from neurons to cross synapses and pass information.

Question 24

True or False:

The nervous system uses electrical signals to communicate between cells.

Answer 24

True

Neurons transmit electrical impulses that carry information quickly throughout the body.

Question 25

# Fill in the blank: The endocrine system **regulates** body processes through the release of \_\_\_\_\_\_\_\_\_\_.

Answer 25

hormones ## Footnote **Hormones** are chemical messengers produced by glands, affecting various body functions.

Question 26

What does **insulin** do in the body?

Answer 26

It helps **lower blood glucose** levels. ## Footnote It is produced by the pancreas and helps cells absorb glucose for energy.

Question 27

What is the primary **function** of the excretory system?

Answer 27

To **remove waste products** and maintain water balance. ## Footnote This system includes the kidneys, bladder, and urethra, which filter blood and eliminate waste.

Question 28

What **organs** are involved in the excretory system?

Answer 28

* Kidneys * Ureters * Bladder * Urethra ## Footnote These organs work together to **filter** waste from blood and excrete it as urine.

Question 29

# True or False: The endocrine system **uses** the bloodstream to deliver signals to target organs.

Answer 29

True ## Footnote Hormones are secreted by glands and carried by the blood to organs and tissues to regulate processes.

Question 30

# Fill in the blank: \_\_\_\_\_\_\_\_\_ is the **process** of breaking down food into smaller molecules.

Answer 30

Digestion ## Footnote This process occurs in the mouth, stomach, and small intestine, using both mechanical and chemical processes.

Question 31

What is the **role** of enzymes in digestion?

Answer 31

They break down **complex** molecules into simpler ones. ## Footnote They speed up the chemical breakdown of food, facilitating nutrient absorption.

Question 32

What substance **emulsifies fats** for digestion?

Answer 32

Bile ## Footnote It is produced by the liver and stored in the gallbladder, aiding fat digestion in the small intestine.

Question 33

What is the role of the **diaphragm**?

Answer 33

It helps **control the expansion and contraction** of the lungs. ## Footnote It moves down to allow air in and up to force air out during respiration.

Question 34

# True or False: The stomach is responsible for **nutrient** absorption.

Answer 34

False ## Footnote The stomach primarily breaks down food, while nutrient absorption occurs in the *small intestine*.

Question 35

# Fill in the blank: The **exchange** of oxygen and carbon dioxide occurs in the \_\_\_\_\_\_\_\_\_.

Answer 35

alveoli ## Footnote Oxygen is absorbed into the blood, and carbon dioxide is expelled in the alveoli of the lungs.

Question 36

What is **reproduction**?

Answer 36

The **process** by which organisms produce offspring. ## Footnote It is essential for the continuation of species. Reproduction can be *sexual or asexual*, involving different methods of offspring production.

Question 37

# True or False: Sexual reproduction involves **only** one parent organism.

Answer 37

False ## Footnote Sexual reproduction requires **two** parents (male and female) to combine genetic material and produce offspring.

Question 38

# Fill in the blanks: In sexual reproduction, the **male** sex cell is called \_\_\_\_\_\_\_, and the **female** sex cell is called \_\_\_\_\_\_.

Answer 38

sperm; egg ## Footnote These **gametes** combine during fertilization to form a zygote.

Question 39

What is a **zygote**?

Answer 39

The fertilized egg **formed** after the sperm and egg unite. ## Footnote The zygote undergoes multiple divisions and differentiates to form tissues and organs.

Question 40

# True or False: Development **involves** changes from fertilization through to maturity.

Answer 40

True ## Footnote **Development** encompasses all stages of growth, including embryonic development, childhood, adolescence, and adulthood.

Question 41

# Fill in the blank: Growth is primarily **achieved** through \_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ and cell differentiation.

Answer 41

cell division ## Footnote *Cell division* increases the number of cells, while differentiation ensures those cells perform specialized functions.

Question 42

# Define: The Immune system

Answer 42

The body’s **defense** system against harmful pathogens. ## Footnote It includes various cells, proteins, and organs that work together to detect and destroy pathogens like bacteria, viruses, and fungi.

Question 43

What **proteins** help neutralize foreign invaders?

Answer 43

Antibodies ## Footnote Each **antibody** is specific to a particular pathogen, and they play a key role in the immune response.

Question 44

What is the role of **white blood cells**?

Answer 44

To **detect** and fight infections. ## Footnote *White blood cells*, including lymphocytes, are key players in recognizing and attacking pathogens.

Question 45

# True or False: Antibodies are **produced** by T cells.

Answer 45

False ## Footnote **Antibodies** are produced by B cells, not T cells. T cells help recognize and destroy infected cells.

Question 46

What is an **antigen**?

Answer 46

A substance that **triggers** an immune response. ## Footnote Antigens are usually found on the surface of *pathogens*, and the immune system reacts to them as foreign invaders.

Question 47

What is an **allergy**?

Answer 47

An **overreaction** of the immune system to harmless substances. ## Footnote Allergies occur when the immune system mistakenly treats harmless substances, like pollen, as threats.

Question 48

# Fill in the blanks: \_\_\_\_\_\_\_\_ immunity occurs when the body produces its **own** antibodies, while \_\_\_\_\_\_\_\_ immunity occurs when antibodies are received from an **external** source.

Answer 48

Active, passive ## Footnote Active immunity develops after infection or vaccination, whereas passive immunity can be transferred through breast milk or antibodies from another person.

Question 49

# True or False: Vaccines provide **passive** immunity.

Answer 49

False ## Footnote Vaccines stimulate the body to produce its own antibodies, providing **active** immunity.

Question 50

What is **herd immunity**?

Answer 50

**Protection** from disease in a population when a large portion is immune. ## Footnote Herd immunity helps protect those who cannot be vaccinated, such as infants or immunocompromised individuals.

Question 51

# Fill in the blank: An autoimmune disorder **occurs** when the immune system \_\_\_\_\_\_\_\_ the body's own cells .

Answer 51

attacks ## Footnote In *autoimmune disorders*, the immune system mistakenly targets normal, healthy cells.

Question 52

What is **rheumatoid arthritis**?

Answer 52

An autoimmune disease where the immune system attacks **joints**. ## Footnote This *leads* to inflammation, pain, and potential joint damage.

Question 53

What is **lupus**?

Answer 53

An autoimmune disease that **affects** multiple organs. ## Footnote Lupus causes the immune system to *attack* organs like the skin, kidneys, and heart.

Question 54

What does **HIV** stand for?

Answer 54

**H**uman **I**mmunodeficiency **V**irus ## Footnote HIV attacks the immune system, specifically targeting **T-cells**, which are crucial for immune function.

Question 55

# True or False: Antibiotics **treat** viral infections.

Answer 55

False ## Footnote Antibiotics only work against **bacterial** infections, not viral infections.

Question 56

What is the **difference** between a bacterial infection and a viral infection?

Answer 56

* Bacterial infections are caused by **bacteria**. * Viral infections by **viruses**. ## Footnote Antibiotics can treat bacterial infections, but viruses require different treatments, such as antiviral medications or vaccines.

Question 57

# Fill in the blank: The immune system’s **response** to an infection is known as the \_\_\_\_\_\_\_\_\_ response.

Answer 57

immune ## Footnote The *immune response* involves detecting pathogens, activating immune cells, and producing antibodies to fight the infection.

Question 58

# True or False: The bone marrow **produces** blood cells, including white blood cells, which play a key role in the immune system.

Answer 58

True ## Footnote *Bone marrow* is a primary site for the production of immune cells, crucial for fighting infections.