Bio Lab Exam Flashcards
(38 cards)
Science
the orderly process of posing and answering questions about the natural world through repeated and unbiased experiments and observations
Steps of the scientific method:
Make observations
testable questions
Formulate hypothesis
gather data
Quantify the data
Test the hypothesis
Refine hypotheses and retest
Answer the questions and make conclusions
What is a hypothesis
A tentative explanation for a phenomena that can be tested
A statement that clearly states the relationship between biological variables
What is a null hypothesis
A hypothesis that says there is no statistical significance between the two variables
What is an alternative hypothesis
A hypothesis that states there is a statistically significant relationship between two variables
What is a standardized variable
The variables that are maintained as constant in all treatments
What is a dependent variable
The variable that depends on other factors
What is an independent variable
The variable that is manipulated in an experiment
Why is it important to include a control group in an experiment
Without a control group, it would be impossible to determine what is changing in the experiment, or what the outcome is
What is accuracy in measurements
A group of measurements refers to how closely the measured values agree with the true or correct values
What is precision in measurements
Refers to how closely the measurements agree with eachother, regardless of their accuracy
Condensor lens:
focuses light from the light source onto the specimen
Ocular
the two eye piece lenses (binocular) or one eye piece lens (monocular)
Stage
secures the glass slide one which the specimen is mounted
Coarse adjustment knob:
allows for quick focusing by moving the stage up and down (initial focusing)
Fine adjustment knob:
slow but precise control used to fine focus the image when viewing at higher
Parts of the stereoscope microscope used to what
view objects that are opaque or too large to see with a compound microscope
Larger working distance
Depth of Field:
The thickness of the object in sharp focus
Resolving power:
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
Working distance:
The distance between the objective lens and specimen
Features of prokaryote cells:
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
Features of eukaryote cells:
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
Plant Cells:
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
Animal Cells:
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