Bio Lab Exam

Question 1

Science

Answer 1

the orderly process of posing and answering questions about the natural world through repeated and unbiased experiments and observations

Question 2

Steps of the scientific method:

Answer 2

Make observations
testable questions
Formulate hypothesis
gather data
Quantify the data
Test the hypothesis
Refine hypotheses and retest
Answer the questions and make conclusions

Question 3

What is a hypothesis

Answer 3

A tentative explanation for a phenomena that can be tested
A statement that clearly states the relationship between biological variables

Question 4

What is a null hypothesis

Answer 4

A hypothesis that says there is no statistical significance between the two variables

Question 5

What is an alternative hypothesis

Answer 5

A hypothesis that states there is a statistically significant relationship between two variables

Question 6

What is a standardized variable

Answer 6

The variables that are maintained as constant in all treatments

Question 7

What is a dependent variable

Answer 7

The variable that depends on other factors

Question 8

What is an independent variable

Answer 8

The variable that is manipulated in an experiment

Question 9

Why is it important to include a control group in an experiment

Answer 9

Without a control group, it would be impossible to determine what is changing in the experiment, or what the outcome is

Question 10

What is accuracy in measurements

Answer 10

A group of measurements refers to how closely the measured values agree with the true or correct values

Question 11

What is precision in measurements

Answer 11

Refers to how closely the measurements agree with eachother, regardless of their accuracy

Question 12

Condensor lens:

Answer 12

focuses light from the light source onto the specimen

Question 13

Ocular

Answer 13

the two eye piece lenses (binocular) or one eye piece lens (monocular)

Question 14

Stage

Answer 14

secures the glass slide one which the specimen is mounted

Question 15

Coarse adjustment knob:

Answer 15

allows for quick focusing by moving the stage up and down (initial focusing)

Question 16

Fine adjustment knob:

Answer 16

slow but precise control used to fine focus the image when viewing at higher

Question 17

Parts of the stereoscope microscope used to what

Answer 17

view objects that are opaque or too large to see with a compound microscope
Larger working distance

Question 18

Depth of Field:

Answer 18

The thickness of the object in sharp focus

Question 19

Resolving power:

Answer 19

Measured by its ability to differentiate two lines or points in an object
greater the resolving power, the smaller the minimum distance between two lines or points that can still be distinguished

Question 20

Working distance:

Answer 20

The distance between the objective lens and specimen

Question 21

Features of prokaryote cells:

Answer 21

Bacteria and cyanobacteria are prokaryotes
Do not contain a membrane bound nucleus or any other membrane bound organelles
The cytoplasm of prokaryotes is enclosed in a plasma membrane covered by a gelly like capsule
Flagella and pili are common in prokaryotes
Flagella: used for movement
Pilli: used to attach some types of bacteria to surfaces or to exchange genetic material with other bacteria
Within the cytoplasm are ribosomes and nueceloid regions

Question 22

Features of eukaryote cells:

Answer 22

Structurally more complex than prokaryotic cells
Robsomes, cell membrane are two similar features between the two
They contain membrane bound nuclei and other organelles
Cytoplasms forms the matrix of the cell and is contained by the plasma membrane
Chloroplasts are organelles in plant cells
The site of photosynthesis in plant cells are green because they contain chlorophyll
Mitochondria are organelles found in plant and animal cells
Where aerobic respiration occurs
All material and organelles contained by the plasma membrane are collectively called the protoplast

Question 23

Plant Cells:

Answer 23

Most mature plants contain large central vacuoles, which occupy most of the volume of the cell
Cytoplasm is often thin layer between the vacuole and the plasma membrane
The cytoplasm contains the cells organelles
They have chloroplasts which is where photosynthesis takes place

Question 24

Animal Cells:

Answer 24

Cells are surrounded by a bilayered plasma membrane containing phospholipids and proteins
The nucleus houses chromosomal DNA and is surrounded by a double membraned nuclear envelope
Central vacuole is the site that provides storage; regulation of cell volume
Chromatin is a complex protein and DNA

Question 25

Primary functions of organelles:

Answer 25

Organelles are subcellular structures that have one or more specific jobs to perform in the cell Energy production Building proteins and secretions Destroying toxins Reponds to external signals Membranous organelles possess their own plasma membrane Nonmembranous organelles are not surrounded by a plasma membrane, and most non membranous are part of the cytoskeleton Filaments, mictrotubules, and centrioles

Question 26

Cyanobacteria:

Answer 26

these are prokaryotes They lack a membrane bound nucleus, mitochondria, golgi apparatus, chloroplasts, and endoplasmic reticulum

Question 27

Gloeocapsa:

Answer 27

Ribosomes

Question 28

What are the properties of an acid:

Answer 28

Molecules that release hydrogen ions (H+) when dissolved in water Acids increase the concentration of H+ in a solution Acids neutralize bases

Question 29

What are the properties of bases:

Answer 29

Molecules that remove H+ from solution Bases decrease the cocnetration of H+ in a solution Bases neutralize acids

Question 30

pH Buffers:

Answer 30

kept relatively constant by buffers, which are mixtures of a weak acid and a weak base that can combine with a strong acid or base to limit changes in pH Buffers absorb excess H+ as the pH decreases or release H+ as the pH increases Buffers minimize changes in pH

Question 31

The building blocks of macromolecules:

Answer 31

Monomers are the building blocks of the four basic macromolecules Monosaccharides are the monomers of carbohydrates Amino acids are the monomers of proteins Fatty acids/glycerol are the monomers of lipids Nucleotides are the monomers of DNA

Question 32

What is a brownian movement?

Answer 32

This movement is the random motion of particles that are suspended in a fluid

Question 33

What is the relationship between molecular weight and diffusion?

Answer 33

A lower molecular weight allows for the faster diffusion A higher molecular weight takes longer for diffusion to finish

Question 34

What factors influence/control the rate of diffusion?

Answer 34

Temperature, pressure, size, solubility, concentration gradient

Question 35

What does tonicity mean

Answer 35

The capability of a solution to modify the volume of cells by altering the water content The movement of water into a cell can lead to a hypotonic solution The movement of water out of a cell can lead to a hypertonic solution

Question 36

How does tonicity affect the volume and integrity of cells

Answer 36

It swells and shrinks when placed in hypertonic solution Water will leave the cell

Question 37

Why is osmosis a type of facilitated transport

Answer 37

It has facilitated transport solution and moves in and out through solution(osmosis) without energy

Question 38

How do the effects of tonicity possibly change the appearance of animal and plant cells

Answer 38

The appearance of the animal and plant when placed in hypertonic solution can lose volume and water leaves the cell It will shrink and die