bio homework lab

Assignment 1:Review1

These questions will cover material in Chapter 2. This is worth 20 points total.

1. What is the difference between a polar and non-polar molecule? (1 point)

2. Is catabolism an endergonic or exergonic reaction? (1 point)

3. Describe the pH scale. Be sure to indicate where acidic, basic and neutral fall on the scale. (3 points)

4. What are the definitions for a monomer and polymer? (2 points)

a. Monomer =

b. Polymer =

5. Complete the chart below. (10 points)

Organic Macromolecules	Monomer	Polymer	Function	Examples
Carbohydrates		polysaccharide
Lipids	Building blocks =glycerol + fatty acid chains	Not a polymer, but still an organic cmpd. like the others
Proteins	Amino Acids
Nucleic Acids		polynucleotide		DNA, RNA

6. What are the components of a nucleotide? (3 points)

Assignment 2:Review 2

1. Complete the following chart.

Organelle	Description	Function	Animal, Plant or Both
CELL WALL	Rigid, tough, made of cellulose
CELL MEMBRANE	Thin, covering, protects cells
CYTOPLASM	Jelly like substance that contains organelles
NUCLEUS	Dense, ball shaped structure, contains DNA
NUCLEAR MEMBRANE	Thin covering over the nucleus
ENDOPLASMIC RETICULUM	Clear, tubular system of tunnels throughout the cell
RIBOSOME	Small specks made of RNA. Found in cytoplasm or on the endoplasmic reticulum
MITOCHONDRIA	Location in the cytoplasm, bean shaped
VACUOLE	Large open storage area, smaller in animal cells
CHLOROPLAST	Green structures that contain chlorophyll
GOLGI BODY	Small bags with tubes connecting them
LYOSOME	Small, round structures, containing enzymes

2. What are the 4 components that every cell must have ?

a.

b.

c.

d.

3. What are the similarities/differences between a prokaryotic and eukaryotic cell?

4. Why is the term “fluid mosaic model” used to describe the plasma membrane?

5. Select the correct responses by putting an X in the box. Some may have more than one answer.

	Diffusion	Osmosis	Active Transport
A substance moves from an area of low concentration to an area of high concentration.
A substance moves and becomes more evenly spread out.
The movement does not use energy and is caused by the random movement of individual particles.
The movement requires energy from respiration.
Only water is involved in this type of movement.

Assignment3: Microscope Virtual Lab

Biologists use the light microscope to see objects that cannot be seen with the naked eye. The light microscope works by shining light from the bottom of the microscope through a specimen and then refracting (bending) the light rays with lenses. This will be discussed in more depth once the parts of the microscope have been covered. 

Most people are aware that microscopes are used to  magnify, which means to make something appear larger. Just making things larger is NOT sufficient, however.  When you make a photograph larger (magnify), eventually the picture will get fuzzy and you may not see the details in the picture any better. 

Observing the details of a specimen is called  resolution .  Resolution allows us to see the parts within a cell.  A fuzzy picture has lost resolution.  Thus, magnification and resolution are both important factors when viewing a specimen with a microscope. 

It is also important to be able to distinguish the specimen from the background; this is called contrast. Sometimes a specimen is treated with chemical stains in order enhance contrast.  Black letters against white background has a high degree of contrast and makes the letter easier to see.  White letters on a white background have no contrast and are difficult to see.   

Parts of the Light Microscope 

Base: This is the bottom portion of the microscope that is grasped when carrying the microscope. 

Arm: This is the handle of the microscope that is used when carrying. 

Eyepiece: This is the area where the eye is placed when viewing specimens.  

Body tube: This cylinder joins the eyepiece to the arm. It contains a lens that magnifies 10X. 

Stage: This is a flat area where slide is placed when viewing a specimen. There is an opening on the stage that allows light to pass through the specimen. 

Stage bracket: This is a contraption that holds the slide on the stage when viewing specimens.  

Stage movement knobs: Some microscopes have knobs that can move the slide around on the stage.    

Light source: This supplies light for viewing. It is turned on and off by the power switch located on the base. 

Condenser: This is a lens beneath the stage that bends light rays on to the specimen. 

Diaphragm: This part controls the amount of light passing through the specimen through the opening on the stage. It is adjusted by a lever that sticks out from beneath the stage. 

Revolving nosepiece: This is a textured knob that allows the user to switch objectives so that different magnifications can be obtained. 

Scanning objective: This is a cylinder that contains a lens that magnifies 4X; in fact, the number 4 is etched on the objective.   This is the shortest objective.   

Low power objective: This is a cylinder that contains a lens that magnifies 10X; in fact, the number 10 is etched on the objective. 

High power objective: This is a cylinder that contains a lens that magnifies 40X; in fact, the number 40 is etched on the objective. 

Oil immersion objective: This is a cylinder that contains a lens that magnifies 100X; in fact, the number 100 is etched on the objective. We have no need to use this lens for our activities.  This is the longest of the objectives.   

Coarse adjustment knob: This is a knob on the arm of the microscope that is used to focus an image when the scanning or low power objective is being used. 

Fine adjustment knob: This is a knob on the arm of the microscope that is used to focus an image when the high power or oil immersion lens objective is being used. 

How a microscope works 

Now that you are somewhat familiar the parts, let’s examine how the light microscope works. Light from the base of the microscope is projected upward. The condenser lens refracts (bends) the light on to the specimen. As light travels upward through the objectives and body tube to the eyepiece, it is bent by additional lenses (a lens in the objective and a lens in the eyepiece), until an image forms on the retina of the eye. This causes images to look flipped when you look at them under the microscope.

 

Magnification 

The magnification power (how many times an object is magnified) is determined by the specific magnification of the objective lens, as written on the objective, and by the magnification of the eyepiece found in the body tube. Total magnification is the mathematical product of magnification of the eyepiece (10X) multiplied by the magnification of the objective that is being used.  

 

1. Fill in the following table: 

The first row has been completed for you. Complete the remaining portions. Remember the magnification of an objective appears on the side of the objective. You will find the lens magnification and adjustment knob use in the “Parts of the Light Microscope” section.

 

Lens	Eyepiece Magnification	Lens Magnification	Calculate Total Magnification	Which adjustment knob is used with this lens?
Scanning	10X	4X	10X * 4X= 40X	Coarse adjustment knob
Low power	10X
High power	10X
Oil immersion	10X

Watch the following video walking though the basics of using a microscope and answer the following questions.

https://www.youtube.com/watch?v=-b3Eejf4rDQ

2. When you first start to look at an image what objective lens should you start with?

3. When starting to observe an image is the stage all the way up or down when you start?

4. What happens to your field of view as he increases magnification of the letter “e”?

Watch the following video featuring the Nikon Small World Competition. It is really cool.

https://www.youtube.com/watch?v=ZyXrtODhJEA

5. What type of organism is shown in the 4th place image? Give the name.

Watch the following video about preparing an Elodea wet mount and images seen under a microscope and answer the following questions.

https://www.youtube.com/watch?v=UWbGZMO4o_U

6. What 4 organelles/cell parts are you able to observe on the Elodea wet mount?

7. What is the term used to describe the chloroplasts moving around in the cell?

Watch the following video about preparing a wet mount of cheek cells and images seen under a microscope and answer the following questions.

https://www.youtube.com/watch?v=i2x3MKSJez4&t=56s

8. What is the name of the stain used in this video?

9. What is the blue dot in the cells?

10. Identify each image below as either an image of bacterial cells, plant cells or animal cells. Type out the answer next to the image.

Assignment 4: Cell Transport Virtual Lab

Part 1: Complete the following virtual lab.

Cell Homeostasis Virtual Lab - Activity

video.esc4.net › video › assets › Science › Biology › ce...

You cannot go back once you start, so be sure to record the numbers in the table before you move onto the next part. If not you have to start over. Be sure to record the answers to the 4 questions at the end of the lab (ex. A, B or C).

1. Complete the table as you go. I started the first one for you.

Beaker	Amt of water (mL)	Amt of sugar added (g)	Beaker Concentration (%)	Dialysis Tubing Concentration (%)	Dialysis Tubing First Weight (g)	Dialysis Tubing Final Weight (g)	Change over 24 hours (g)
A	1000	0	0	0	17.59	17.66	-0.07
B
C
D
E

2. What letter was the answer to the first question about which bags had little to no change in mass?

3. What letter was the answer to the second question about why water was used as the control group?

4. What letter was the answer for the third question asking why the weights did not change for bags A and D?

5. What is the letter for the fourth question that asks how the cell responds to the external environment?

Part 2: Watch the following video and answer the following questions.

https://www.youtube.com/watch?v=SrON0nEEWmo

6. What was the purpose of the vinegar in the experiment?

7. When the egg was placed into the corn syrup what happened to the size of the egg? What is this due to?

8. When the egg was placed int the glass with blue water what happened to the size of the egg? What is this due to?