LAB EXAM 1 - Biology Studying (stolen) by -Audie- elizabeth

lab exam 1 biol1110

98% of an organism's mass can be attributed to six elements. Which six?

CHONPS

Atoms of an element may have different numbers of neutrons in the nucleus. These atoms are called _______ of an element.

isotopes

In an atom, the first electron shell can hold ___ electrons, and the second can hold up to ___ electrons. Separate your answers with a comma!

2,8

The outermost electron shell is called the _______ shell, and contains electrons with the _______ amount of energy.

valence,greatest

In the case of atoms with more than one electron shell, atoms are most stable when they have eight electrons in their valence shell. (True/False)

true

An ionic bond, such as that between sodium and chlorine ions, is formed when

ions of opposite charge are attracted to one another

Carbon has an atomic number of 6, with 2 electrons in its innermost shell, and 4 electrons in its valence shell. How many covalent bonds will it need to form to complete its valence shell?

4

Which of the following atoms would you predict to be the most electronegative within a polar covalent bond? (Which is closest to filling its outer electron shell?)

A) Nitrogen

B) Oxygen

C) Carbon

D) Phosphorus

oxygen

Most of the unique properties of water result because water molecules form _______ bonds with each other.

hydrogen

In lab, the appropriate unit for measuring mass is ___.

grams

In lab, an appropriate unit for measuring volume is ___.

liters

Place the sequence of the scientific method in order:

1. Design an experiment and collect data

2. Make observations and ask questions

3. Form a hypothesis

4. Draw conclusions

Separate your answers with commas, no spaces!

2,3,1,4

If your hypothesis is accepted (your data supports your hypothesis), you can say that you "proved" something to be true. (True/False)

false

Even if your hypothesis is rejected, it still adds to scientific knowledge and may lead to new research questions. (True/False)

true

An experiment was designed to measure the growth of common houseplants in the presence of different kinds of music. Each plant had the same soil, moisture, and light. The height of each plant was measured at the end of the study.

In this scenario, what is the independent variable?

music

An experiment was designed to measure the growth of common houseplants in the presence of different kinds of music. Each plant had the same soil, moisture, and light. The plant height was measured at the end of the study.

In this scenario, what is the dependent variable?

plant height

An experiment was designed to measure the growth of common houseplants in the presence of different kinds of music. Each plant had the same soil, moisture, and light. The height of each plant was measured at the end of the study.

In this scenario, what are the examples of control variables? Separate answers with commas!

soil,moisture,light

In the pillbug activity, which statistical test will we use to account for variation due to chance?

chi-square test

Electrons in the outermost level, or shell, are called _______ electrons.

valence

What type of bond holds an oxygen atom and a hydrogen atom together within a water molecule?

polar covalent

Based on your knowledge of the polarity of water molecules, the solute molecule depicted here is most likely _____.

positively charged

The partial negative charge at one end of a water molecule is attracted to the partial positive charge of another water molecule. What is this attraction called?

hydrogen bond

In lab, water moved up a greater distance up into a glass tube with a smaller internal diameter. This was a representation of

capillary action

A hydrophobic molecule is nonpolar. (True/False)

true

Which of these is found in some but not all cells?

A) Nucleus

B) DNA

C) Cytosol

D) Plasma Membrane

nucleus

What does magnification mean?

the apparent increase in size of an image

The total magnification of a microscope with a 10X ocular and a 40X objective is ___.

400X

What does parfocal mean?

the ability of a microscope to switch from one objective lens to another with minimal focusing adjustment

Which concept will we explore when we view the "stack of colored threads" slide under the microscope?

depth of focus

What two microscopes are electron microscopes? Separate answers with a comma!

TEM,SEM

What organelle would you find in plant cells but NOT in animal cells?

chloroplasts

In this lab, you will view a slide with animal cells stained with methylene blue. What is the source of the live animal cells used in this lab?

human

Due to their bright color, some organelles in the plant cell will be easier to recognize. The green organelles found in some plant cells are called ___.

chloroplasts

What does the bacillus bacteria shape look like?

rod-shaped

What does the spirillum bacteria shape look like?

spiral-shaped

What does the coccus bacteria shape look like?

spherical

What degrees celsius does water boil? Don't type degrees symbol!

100

What degrees celsius does water freeze? Don't type degrees symbol!

0

What degrees celsius is a human being? Don't type degrees symbol!

37

What is the total magnification of a stereoscope with 15X oculars and a 2X objective setting?

30X

What accurately describes cell membranes?

a phospholipid bilayer with proteins

What kind of transport requires expended energy? (ATP)

active transport

What kind of transport does not require energy?

passive transport

Compound A (molecular weight = 350) diffuses 50 mm within a tube of gelatin.

Compound B (molecular weight = 750) diffuses 30 mm within a tube of gelatin.

Compound C diffuses 44 mm within a tube of gelatin.

Which of the following is most likely to be the molecular weight of Compound C? (Type the number, not the letter)

A) 234

B) 512

C) 814

D) 1032

512

If the solution in the dialysis bag has a higher solute concentration than the solution in the beaker, then solution in the dialysis bag is_____ to the solution in the beaker.

hypertonic

In lab this week you will test the effects of two factors on the rate of diffusion. What are these two factors? Separate them with a comma!

temperature, molecular weight

In the Structure and Function of Membranes lab, you will be using sucrose solutions. What is the solute and solvent? (Answer as "solute, solvent")

sucrose, water

Which two structures found in plant cells (but not in animal cells) are responsible for the different ways the cells respond to hypotonic environments? Separate answers with a comma!

cell wall, central vacuoles

How will you determine if the contents of the artificial cells (dialysis bags) have changed?

change in mass

Which factor determines whether it is possible for a substance to pass across the dialysis tubing membrane?

molecular size

What substance does biuret reagant indicate?

protein (albumin)

What substance does barium chloride (BaCl2) indicate?

sulfate ions

What substance does silver nitrate (AgNO3) indicate?

chloride ions

What substance does iodine (I2KI) indicate?

starch

Enzymes work on one or more reactants called _____.

substrates

What happens to the enzyme at the end of an enzyme-mediated reaction?

the enzyme is unchanged

Which of the following is NOT revealed in the name of the compound 'catechol oxidase'?

the name of product

Several factors can cause an enzyme to denature. What two factors are investigated in this lab exercise? Separate answers with a comma!

pH, temperature

What is changed when an enzyme is denatured?

the active site

What role did oxygen and catechol play in the enzymes lab?

substrates

What role did benzoquinone play in the enzymes lab?

product

What role did catechol oxidase play in the enzymes lab?

enzyme

What role did copper ion play in the enzymes lab?

cofactor

Is the energy of activation lower or higher in the presence of an appropriate enzyme?

lower

How did you recognize the formation of product in the reaction studied in the enzymes lab?

the intensity of color

As temperature increases, the rate of diffusion

increases

As the molecular weight of a solute increases, the rate of diffusion

decreases

If a semipermeable membrane separates a 10% sucrose solution and a 30% sucrose solution, which will show a net loss of water?

the 10% sucrose solution

If a semipermeable membrane separates a 10% sucrose solution and a 30% sucrose solution, which one is hypertonic?

the 30% sucrose solution

Normal saline, which is 0.9% NaCl, is isotonic with body cells and fluids, and can be safely used intravenously.