Download MCA Review Part I - Learn District 196

Homeostasis
Homeostasis: the maintenance of constant internal conditions in an organism
Read about homeostasis on page 9 and answer the following questions:
1. Why is homeostasis important?
Cells function best within a certain range of conditions
2. List the limited range of conditions that cells function best within:
Temperature, pH, blood sugar
3. Are homeostatic responses voluntary, involuntary, or both? Explain.
Both.
Involuntary: nervous system regulation such as sweating, blood sugar maintenance
Voluntary: putting on a jacket, reptiles sitting on warm rock
3. What are some examples of behavioral responses and organism would do to maintain homeostasis?
Those listed above; eating food when hungry, staying indoors when it is cold out
Homeostasis
a. Plants also need to maintain homeostasis; ANY living thing needs to.
Read about gravitropism and phototropism (on pg 640) and how
plants use these processes to maintain homeostasis.
1. What is gravity? What is gravitropism and how do
plants use this to maintain
homeostasis?
Gravitropism: When a seed germinates underground,
-the root grows downward into the soil, (+)
-the shoot grows upward, (-)
2. What is phototropism and how do plants use this to
maintain homeostasis?
Phototropism: the tendency of a plant to grow towards s
unlight
4. A cell’s response to maintain homeostasis may include singlecelled organisms or individual cells of organisms
a. True
b. False
Homeostasis
Terms:
Determination: when a cell becomes committed to develop into
only one cell type
Differentiation: the process by which committed cells acquire
the structures and functions of highly specialized cells
Homeostasis: the maintenance of constant internal conditions in
an organism (temp, fluids, salts, pH, nutrients, gases)
Feedback: information from sensors that allows a control center
to compare current conditions to a set of ideal values.
Negative Feedback: a control system that counteracts any
change in the body
1. What are the five levels of organization in the human body?
Cells > Tissues > Organs > Organ Systems > Whole
Organism
Digestive System

Function:



Breaks down and absorbs
nutrients, salts, and water
Eliminates some wastes
Organs:








Mouth
Pharynx
Esophagus
Stomach
Small/Large Intestines
Pancreas
Gallbladder
Liver
Digestive System

http://www.youtube.com/watch?v=Z7xKYNz9AS0
Respiratory System

Function
 Brings
in Oxygen for
cells, expels Carbon
Dioxide and Water
Vapor

Organs
 Nose
 Sinuses
 Pharynx
 Larynx
 Trachea
 Lungs
Respiratory System

http://www.youtube.com/watch?v=HiT621PrrO0
Circulatory System

Function
Transports oxygen, nutrients,
wastes
 Helps regulate body
temperature
 Collects fluids lost from
blood vessels


Organs
Heart
 Blood Vessels
 Blood
 Lymph Nodes
 Lymphatic Vessels

Circulatory System

http://www.youtube.com/watch?v=PgI80Ue-AMo
Immune System

Function
 Protects
against disease
 Stores and generates
white blood cells (WBCs)

Organs
 White
Blood Cells
 Thymus
 Spleen
Immune System

http://www.youtube.com/watch?v=9uWaPtxTYvk
Nervous System

Function
 Regulates
body’s response to changes in internal and
external environment; processes information

Organs
 Brain
 Spinal
Cord
 Peripheral Nerves

http://www.youtube.com/watch?v=xRkPNwqm0mM
e. Plant Systems.
1. Read about the movement of fluids through
plants in figure 2.2 on pg 604. Explain
how absorption and transpiration help
move fluids through plants.
Water and minerals in the soil are
pulled into roots, tension/pressure is
created the moves water upward, water
evaporates through transpiration
2. Read about the pressure-flow model of
plants in figure 2.4 on pg 606 and
explain how nutrients/sugars move
through plants:
1. Sugars move from their source to a
sink (leaves or roots to fruit)
2. Water moves from high to low
concentration, which helps move sugars
3. Extra sugars are moved to where
they are stored
1. Cells are primarily composed of what 6 elements? What are
their symbols?
CHNOPS: Carbon, Hydrogen, Nitrogen, Oxygen,
Phosphorus, Sulfur
2. What is the basic molecular structure and function of
carbohydrates? What are some examples?
Structure: C,H,O; Ring Structure
Function: energy, plant cell structure
Examples: glucose, starches, glycogen, cellulose
3. What is the basic molecular structure and function of Lipids?
Draw and label a phospholipid.
Structure: C,H,O; glycerol + 3 fatty acids
Function: Energy, Cell structure
Examples: Animals fats (meat and butter), Plant fats (olive
oil, peanut oil), Cholesterols (hormones, steroids)
a. Lipids make up what important part of cells? What is this
term?
Cell Membrane
Phospholipid Bilayer
-Polar Head
-Nonpolar Tails
4. What is the basic molecular structure and function of Proteins?
What are some examples?
Structure: 20 Amino Acids, C,H,O,N, sometimes S
-amine group, carboxyl group, side group or R-group
Function: movement, eyesight, digestion, etc
Examples: serine, lysine, leucine, proline, etc
a. How are proteins and amino acids related?
Proteins are made up of amino acids
5. What is the basic molecular structure and function of Nucleic Acids?
Structure: made up of nucleotides:
-sugar
-phosphate group
-nitrogen base (ATCG or AUCG)
Function: make proteins
a. What are the two main types of nucleic acids?
DNA & RNA
Example
Relative
Size
Where is
DNA?
Organelles
Prokaryote
Bacteria
Archaea
0.2-2.0 mm In
Cytoplasm
– no
nucleus
Absent
Eukaryote
Animals
Plants
Fungi
Protists
10-100 mm In nucleus
Yes –
ribosomes,
mitochondri
a,
Chloroplast
7. Viruses and bacteria are both pathogens but they
differ from each other in structure. What are viruses
made of? Use pg 510.
A strand of DNA or RNA surrounded by a protein
coat
Structure
Function
Nucleus
Contains nucleolus and
nuclear envelope
Storehouse for DNA
Ribosome
Some “studded” on the Link Amino Acids
endoplasmic reticulum, together to form
or free within
proteins
cytoplasm
Mitochondria
Bean-Shaped, 2
membranes, highly
folded
Cell Respiration:
Transforms energy into
a usable form
Cell Wall
Rigid Layer
Provides protection,
support, and shape
Chloroplast
Bean Shaped, 2
membranes, highly
folded
Photosynthesis:
converts solar energy
into energy-rich
molecules (food)
Picture
Cell Membrane
9. Cell Membrane (pg 77-80). What is the function
of the cell membrane?
Forms a boundary between the cell and the
outside environment, and controls the passage
of materials into or out of the cell.
a. The cell membrane has the property of
selective permeability, what does this mean?
It allows some, but not all materials to cross.
Allows, a cell to maintain homeostasis.
b. How are chemical signals transmitted across
the cell membrane?
Through receptors: a protein that detects a
signal molecule and performs an action in
response
Passive Transport
10. Use pg 81-87 for 10 and 11. Passive transport of materials
across the cell membrane. Why do materials move across cell
membranes? What is this term?
To get needed materials (ie: nutrients, O2) into the cell and
unneeded materials or waste out of the cell (CO2). Passive
transport is the movement of molecules across a cell
membrane without energy input from the cell.
List and describe the three main types of passive transport:
**All are due to a concentration gradient: the difference in
the concentration of a substance from one location to
another.
1. Diffusion: movement of molecules in a fluid or gas
from a region of higher concentration to a region of lower
concentration.
2. Osmosis: diffusion of water across a cell membrane.
3. Facilitated Diffusion: the diffusion of molecules across
a membrane through transport proteins.
Active Transport
11. Active transport of materials across the cell
membrane. What is active transport? How is
it different from passive transport?
Drives molecules across a membrane from
a region of lower concentration to a
region of higher concentration. Going
against the concentration gradient, thus
requires energy.
a. Describe Endocytosis: the process of
taking liquids or fairly large molecules by
engulfing them in a membrane.
b. Describe Exocytosis: the release of
substances out of a cell by fusion of a
vesicle with the membrane.
Asexual Reproduction/Mitosis
12. Draw out the cell cycle (figure
1.1) from pg 126 below:
13. Label each phase of
mitosis/asexual reproduction
below:
14. Which cells undergo
mitosis/asexual reproduction?
What is the final result of mitosis?
-Eukaryote Cells: Somatic/body
cells
-Two genetically IDENTICAL cells
(humans = 46 chromosomes)
Binary Fission

15. Prokaryote cells have a
much simpler way of
reproducing. Identify and
describe this process; pg
140.
 Binary
Fission: the asexual
reproduction of a singlecelled organism by division
into two roughly equal
parts.