Download Systems and Balance in Organisms PAP Biology Test

Systems and Balance in Organisms
PAP Biology Test Review KEY
Cell Specialization and Levels of Organization
1. Beginning with a cell, describe how the body is organized.
Similar cells are organized into tissues; different tissue types make up organs; organs
with similar functions make up organ systems; organ systems work together to make
up a multi-celled organism.
2. Describe distinguishing characteristics of the following cell types that relate to their
function:
a. Neuron (nerve cell) – dendrites and axons extend from the cell body of a
neuron to receive and send electrical signals to other cells
b. Sperm – has a long, whip-like tail called a flagella to allow it to move through
fluids
c. Red blood cell – mature RBCs discard their nucleus which allow their round,
biconvex shape to move freely through blood vessels; they contain
hemoglobin which carries oxygen molecules to cells
d. Muscle cell – these cells form bundles and contain proteins (actin and
myosin) that overlap to allow for contraction of cell
e. Cells of small intestine – cells have structures called microvilli that increase the
surface area available for absorption of nutrients
Describe the structure and functions of all body systems (See chart on page 848 and list
each body system and its major functions.)
Nervous System (ch 41)
3. What is the main function of the nervous system? Receives and sends quick
electrical messages to neurons or other cell types to maintain homeostasis
4. Which structures make up the Central Nervous System? Brain and spinal cord
5. Which structures make up the Peripheral Nervous System? Sensory and motor
neurons that branch off of the brain and spinal cord
6. What does the autonomic nervous system control? Smooth and cardiac muscles in
heart, blood vessels, digestive, urinary, endocrine, respiratory, and reproductive
systems.
Is it under involuntary or voluntary control? involuntary
7. What does the somatic nervous system control? Skeletal muscle movement
Is it under involuntary or voluntary control? voluntary
8. Put the following functions in order to describe the activities of the nervous system:
_5__ Effector
_3__Integration
_2__Sensory Input
_4__Motor Output
_1__Sensory Receptor
9. What is a dendrite? Nerve cell extensions that receive incoming messages
10. What is an axon? Nerve cell extension that sends outgoing messages
11. What is a synapse? The junction between two neurons or a neuron and another cell
Endocrine System (ch 42)
12. What is the main function of the endocrine system? Maintains homeostasis by the
release of hormones into the bloodstream
13. What is a hormone? A chemical messenger molecule
14. What is a secretory cell? A specialized cell that secretes a hormone or hormones
15. What is a target cell? A cell that has a receptor for a particular hormone
16. Describe the difference between how a protein hormone and a lipid (steroid)
hormone regulates cell activities. Protein hormones are polar molecules and
cannot pass through the phospholipid bilayer; instead, they attach to a receptor
outside of the cell and signal second messengers to relay the message. A steroid
hormone is nonpolar and can activate or inactivate transcription and translation of
a gene by passing directly through the cell and nuclear membranes and binding
to DNA.
17. What is positive feedback? A mechanism that signals an endocrine gland to
continue to release more hormone (examples include milk letdown, uterine
contractions during labor, and blood clotting)
18. What is negative feedback? A mechanism that signals an endocrine gland to stop
releasing hormone once levels return to normal. (Examples include temperature
control, blood sugar control, calcium levels)
19. Which is most often used to maintain homeostasis in the body (positive or negative
feedback)? Negative feedback is almost always used.
20. Which endocrine gland produces and secretes insulin and glucagon? The
pancreas
21. Describe how insulin and glucagon control blood glucose levels in the body. When
blood glucose is high (after a meal), the pancreas releases insulin to carry the
glucose to the body cells and store excess in the liver and muscles as glycogen.
Insulin is released until blood glucose levels return to normal. When blood glucose
becomes too low (between meals), the pancreas releases glucagon to signal the
breakdown of glycogen in the liver into glucose, which is released back into the
blood and restores normal level.
Immune System (ch 40)
22. What is the main function of body defenses and the immune system? Prevent
invasion of foreign cells or particles
23. What is a pathogen? Anything that causes disease; an infectious agent
24. Give three examples of the body’s nonspecific first line of defense. Skin, mucous
membranes, hair, earwax, stomach acid
25. Give three examples of the body’s nonspecific second line of defense.
Phagocytes, fever, inflammation, natural killer cells, interferons
26. What is the purpose of the inflammatory response?
To increase blood supply to the injured area. This brings white blood cells and
nutrients and carries away waste material more quickly.
27. What is the purpose of a fever? A fever increases metabolic activity and inhibits
bacterial growth.
28. Name two white blood cells (lymphocytes) involved in the specific third line of
defense (immune system). T cells and B cells
29. What is an antigen? A foreign particle that elicits an immune response
30. Which WBCs are phagocytic and can present antigens on their surface?
macrophages
31. Which WBCs kill infected cells by causing them to lyse (burst open)? Cytotoxic T
cells
32. Which WBCs produce antibodies that block invader from entering a new cell? B
cells
33. What is a memory cell? A cloned B or T cell that remains behind after an infection
has passed to patrol the bloodstream in case of an invasion in the future.
34. Describe how a vaccine or exposure to an antigen through illness can lead to
immunity. When the body is exposed to an antigen, either through illness or
vaccine (dead or weakened pathogen), an immune response is triggered,
developing memory cells and antibodies that remain in the body to prevent future
infection.
Be able to identify the major structures from the worm and rat dissections in class.