Lab Exam Flashcards
Know what a red blood cell looks like within a hypotonic, hypertonic, and isotonic solution.
Hypertonic (shriveled), isotonic (normal), hypotonic (puffed up and bursting)
What are erythrocytes?
Erythrocytes are red blood cells without a nucleus.
How should red blood cells react to hyperosmotic, hypoosmotic, and isosmotic solutions?
- In hyperosmotic solutions, red blood cells crenate (shrink) due to salt.
- In hypoosmotic solutions, red blood cells lyse (explode), due to the excess water coming in.
- In isotonic solutions, the red blood cells are stable because the solution is balanced.
What occurs during the lysis or hemolysis of a cell?
During lysis or hemolysis, the cell is exploding since water is coming in and making the cell expand. Hemolysis can’t be reversed.
What happens to a cell when it is crenate?
When a cell is crenate it shrinks due to the salt in the solution.
Which is not a step to prepare a tap water Elodea slide?
Obtain a clean glass slide, hypertonic solution, and lab gloves. Put on lab gloves and retrieve Elodea sp. culture. Make a wet mount of Elodea leaf. Observe the condition of the leaf with the scanning, low, and high-dry objectives. The leaf should be turgid. Draw several fully hydrated leaf cells that are visible with a high-dry objective.
What is plasmolysis?
Plasmolysis is the cell losing water. All the organelles are dying, and the chloroplasts bundle to the middle b/c no central vacuoles in the cytoplasm.
Which statement describes turgor?
Turgor is pressing a lot of pressure on the cell wall.
Which statement describes turgor pressure?
Turgor pressure is pressing a lot of pressure on the cell wall.
Why does water leave a plant cell when it is placed in a hypertonic solution?
Water leaves the plant cell in a hypertonic solution because it wants to move towards areas with high solubility, or solution concentration.
What substances keep the plant cell turgid?
high solute concentration in the cell and water.
How does one clean and handle a microscope?
Grasp the microscope with one hand and support it at the base with the other, do not touch lenses with your fingers, do not use paper towels or cloth to wipe the lens (use lens paper), do not allow liquid near the microscope.
How do you find the magnification of our light microscopes we use within the lab (i.e.
how is it calculated)?
You read the objective lens and multiply it by 10.
What are the three most common magnifications to find on a light microscope?
X40, x100, x400
When does one make a wet mount?
You make a wet mount when you are focusing on a direct examination of living specimens/non-living materials for a short time; this can determine the size and shape relationship, motility, and reactions to various chemicals of an organism.
How does one make a wet mount?
Materials: glass slide, coverslip, elodea, bottle with water.
- Clean slide
- Take some water and place 2-3 drops on a glass slide
- Pick out a leaf from the elodea plant and CAREFULLY & GENTLY place it on the water drops.
- Place the coverslip carefully & slowly/gently
- Gently push down on the coverslip
When does one use oil immersion?
Oil Immersion - allows the highest magnification to be used due to the refractive index of the oil to be the same as the lenses.
- The oil acts as an additional lens in the system and prevents the loss of necessary light rays
- Can be used on dead materials and organisms
How does one use oil immersion? (watch the video on the PowerPoint for all of the
steps)?
You use oil by raising the stage until the oil immersion objective touches the slide but no further than the point where it just touches and this is going to be done using the coarse focus of the microscope and slowly turning it away from you which raises the stage and very slowly getting our eyes down where we can see what’s happening and watch between the interphase lense and the drop of oil so we slowly raise the stage seeing the drop of oil and when the lens hits the drop of oil you see the light scatter. Use fine focus to get the image where you can see it clearly. Adjust the eyepiece and slowly turn it away from you. Concentrating until you can see some color.
Know how to identify all parts of a living onion
Foliage leaves: Leaves on top
Scale Leaves: The Dead Leaves on the Side
Adventitious roots: The bottom roots
What is the function of the foliage leaves and scale leaves on the onion?
Foliage leaves - responsible for photosynthesis
Scale leaves - dead; used to protect onion from decomposition
What is taking place within a meristematic region of a plant root?
All mitosis takes place here - it is above the root tip
What is the function of a root cap on a plant root?
Protects root tip and secrets a lubricant that allows it to move through the soil
Know how to identify the interphase stage of mitosis.
Cell Growth Occurs, replicating its DNA
Know how to identify the prophase stage of mitosis.
Chromosomes first become visible
Know how to identify the metaphase stage of mitosis.
Chromosomes move to the middle of the spindle
Know how to identify the anaphase stage of mitosis.
Chromosomes break; sister chromatids move to opposite ends of the cell
Know how to identify the telophase stage of mitosis.
The Cells Finally Separate
What is the function of the spindle? What are the structural components of the spindle?
The Spindle separates the chromatids during mitosis to opposite sides of the cell. It is made up of spindle fibers and microtubules.
What is the function of the spindle? What are the structural components of the spindle?
The Spindle separates the chromatids during mitosis to opposite sides of the cell. It is made up of spindle fibers and microtubules.
Chromosomes move to the middle of the spindle during what phase?
Metaphase
During which phase do the cells separate?
Telophase
During which phase do chromosomes first become visible?
Prophase
Does cell growth occur during interphase or mitosis?
Interphase
Does the nuclear membrane dissolve during interphase or mitosis?
Mitosis
Do chromosomes distribute equally to daughter cells during interphase or mitosis?
Mitosis
Does DNA synthesis (replication) occur during interphase or mitosis?
Interphase
Does the cytoplasm divide during interphase or mitosis?
Mitosis
What is the end product of mitosis?
Cytokinesis - Two identical daughter cells are made
When can a flower be called “complete?”
Both female and male parts
What are the male parts of a flower?
Stamen (made up of filament and anther)
What are the female parts of a flower?
Pistil (stigma, style, ovary, and ovule)
Regarding flower anatomy, what is the definition of a (a) whorl, (b) receptacle, (c)
peduncle, (d) inflorescence, and (e) pedicel?
- Floral organs’ formation in a circle
- The tip of a modified stem
- The modified stem itself
- A cluster of flowers
- The modified stem where the receptacle is found if a cluster/inflorescence is found
What is a sporangia? What is the difference between microsporangia and megasporangia?
Sporangia- diploid part of the plant that is the reproductive area that produces gametes
- Microsporangia - male reproductive organs that make sperm
- Megasporangia - Female reproductive organs that make sperm
What are meiospores?
The cells that go through meiosis and eventually turn into gametes
What are the number and type of cells that result from meiosis vs. mitosis.
Mitosis has 2 identical diploid cells. Meiosis produces 4 haploid cells
How do the genetic contents of cells resulting from mitosis and meiosis differ?
Meiosis has 4 cells at the end while mitosis has 2
If a diploid cell containing 28 chromosomes undergoes meiosis, how
many chromosomes will each daughter cell have?
14
How are mitosis and meiosis similar or different?
- Similar - 2 new cells are produced at the end of mitosis and meiosis 2.
- Differences - meiosis has 4 cells at the end while mitosis has 2
What is the difference between a viroid, prion, and virus?
- Viroid - small circular naked RNA molecule capable of infecting the host
- Prion - INfectious proteins that misfold your proteins
- Virus - small, noncircular infectious DNA or RNA cored(?), non-living.
What can be the components of a virus and what are their functions?
- Capsids - protein-based covering of nucleic acid core
- Core of virus - replicates in a similar manner to us in our cells; RNA
- Envelope - Lipid bilayer; absorbs outside layer of host’s cells
- Spikes - proteins that allow the virus to attach itself to a host cell
What does it mean if a virus is “naked?”
Ability to attach themselves to the host cell with spikes not present in an envelope
What occurs during the lytic cycle of a virus (in detail as discussed in the lab)?
In the lytic cycle, the whole cycle will be complete within an hour.
What occurs during the lysogenic cycle of a virus (in detail as discussed in lab)?
The virus will lay dormant and only replicate when the host cell replicates
What is the definition of a virus?
A submicroscopic pathogen
What are viruses doing before they infect a host? What is their only goal?
They wait in a crystalline form somewhere between life and death. Their only goal is to reproduce by waiting for a living host
What does a virus have to do to “live” or reproduce? Why (explain)?
To live, it enters and utilizes another cell because it doesn’t have the machiner to live on its own
What type of microscope, in the 1930s, had to be invented in order to observe viruses? What
was its magnification?
Electron microscope at 7000 times magnification
The AIDS virus has a core that contains ________, it’s a package of ________ enveloped in a set of ______ that allow the virus to utilize the cell for its own replication because it cannot function independently (cannot multiple independently).
Genetic Information, nucleic acid, proteins
How are the genes of a virus protected?
Thin shell studded with molecules that enable it to dock with a target cell and work its way inside.
The red plague that affected humans during the Peloponnesian war in the 5th century BC was probably due to which virus(es)? What virus was the scourge of the Middle Ages? What virus was mentioned in the Egyptian tombs when they were opened?
The red plague was likely typhus, scarlet fever, or measles. The scourge of the Middle Ages was smallpox. Polio was inside Egyptian tombs
One of the worst natural disaster in recorded history was caused by a virus. Which virus and what year? How many people were killed world-wide? How did this virus spread so easily?
The Influenza pandemic of 1918 killed at least 20 million people world-wide. The strain spread a lot because of the war. When allied forces met in northern France, the exchanged a lethal strain of the flu. This then went from France to the US.
What is the definition of a vaccine? What was the first vaccine created to kill?
A virus stimulating an immune response. The first vaccine was small pox.d
How does your body kill a virus or bacteria? Understand the recognize, destroy, and memory prompts given in the video.
- Your body kills virusis or bacteria with your immune system.
- Recognize: Antibodies flag them for destruction
- Destroy: white blood cells destroy viruses or infected cells.
- Memory: once destroyed, the memory recognize that virus if it enters your body again and protects you, which is how vaccines work.
Influenza viruses are usually grown in the lab in what organism?
Chicken embryos