Cells Flashcards
What are eukaryotes?
Organisms with complex cells containing a nucleus.
What are prokaryotes?
Simple, smaller cells without a nucleus.
What is the cell membrane function>
Controls entry and exit of substances in cells.
What is cytoplasm?
Liquid where cellular reactions occur and organelles reside. Jelly ike substance
What does the nucleus contain?
Contains DNA for protein coding and cell function.
What is the function of the cell wall?
Provides structure and rigidity, made of cellulose.
What are chloroplasts?
Site of photosynthesis, contains chlorophyll pigment.
What occurs in mitochondria?
Where aerobic respiration occurs, producing energy.
What are ribosomes?
Sites of protein synthesis within cells.
What are plasmids?
Small rings of DNA in bacterial cells.
What is cell differentiation?
Process where cells gain specific functions.
What are stem cells?
Cells capable of differentiating throughout life.
What is the function of sperm cells?
Specialized for delivering male DNA to egg.
What do nerve cells do?
Transmit electrical signals quickly across distances.
What are muscle cells specialized for?
Specialized for contraction and movement.
What are root hair cells specialized for?
Specialized for water and mineral uptake.
What do xylem cells transport?
Transport water and minerals from roots to shoots.
What do phloem cells transport?
Transport products of photosynthesis throughout plants.
What is lignin?
Chemical that strengthens xylem cells and withstands pressure.
What is the acrosome?
Contains enzymes to penetrate egg cell membrane.
What are dendrites?
Extensions that connect nerve cells for signal transmission.
What is glycogen?
Stored energy source for muscle cell respiration.
How is surface area increased in root hairs?
Increased by root hairs for efficient water absorption.
What are sieve plates?
Structures in phloem allowing substance movement.
What are orders of magnitude?
Comparative sizes expressed as powers of ten.
What is cell sap?
Liquid in vacuoles, maintains cell turgidity.
What are specialized cells?
Cells adapted for specific functions in organisms.
What is mitosis?
Process of cell division producing two identical cells.
What are red blood cells?
Cells that transport oxygen around the body. Also they are, Cells that lose their nucleus and cannot divide.
What are adult stem cells?
Cells that can differentiate and divide. Thye come from Bone marrow. Thye can only differentaite into blood cells like red blood cells, white blood cells and platelets.n
What is cell differentiation?
Process where cells develop specialized functions.
What is microscopy?
Use of microscopes to view small structures.
What is a light microscope?
Uses light to magnify images up to x2000.
What is resolving power?
Ability to distinguish between two points.
What is an electron microscope?
Uses electrons for higher resolution imaging.
What does a scanning electron microscope do?
Creates 3D images of surfaces.
What does a transmission electron microscope do?
Creates 2D images of internal structures.
What is the magnification formula?
Eyepiece magnification x objective magnification.
What is the size calculation formula?
Size of object = size of image/magnification.
What is standard form?
Representation of numbers as a x10^n format.
What is a culture medium?
Nutrient solution for growing microorganisms.
What is nutrient broth?
Liquid medium for bacterial growth.
What is an agar gel plate?
Solid medium for growing bacterial colonies.
What is an inoculating loop?
Tool for spreading microorganisms on agar.
What is sterilization?
Process to eliminate unwanted microorganisms.
What is the optimal incubation temperature for bacteria?
Optimal growth temperature for bacteria is 25°C.
What is binary fission?
Asexual reproduction in bacteria, dividing every 20 minutes.
How do you calculate bacterial division?
Initial bacteria x 2^number of divisions.
What is an inhibition zone?
Clear area around antibiotic disc on agar.
What is antibiotic resistance?
Ability of bacteria to survive antibiotic exposure.
What is a control disc?
Disc soaked in sterile water for comparison.
What is contamination prevention?
Steps taken to avoid unwanted microorganisms.
What is a petri dish?
Container used for culturing microorganisms.
What is an autoclave?
Device for sterilizing equipment using high pressure.
What is UV light sterilization?
Using ultraviolet light to kill microorganisms.
What is condensation prevention?
Sealing lids partially to avoid moisture.
What does a larger zone of inhibition indicate?
Larger zone indicates more effective antibiotic.
What is the cross-sectional area formula?
Area calculated using formula πr².
What are chromosomes?
Structures containing DNA, found in cell nucleus.
What is a gene?
DNA segment coding for a specific protein.
What is the diploid number in humans?
46 chromosomes in human body cells.
What are gametes?
Sex cells with 23 chromosomes each.
What is the cell cycle?
Series of stages for cell division.
What is interphase?
Cell growth and DNA replication stage.
What is cytokinesis?
Final stage where two daughter cells form.
What is asexual reproduction?
Reproduction involving one organism via mitosis.
What is a stem cell?
Undifferentiated cell capable of division.
What are embryonic stem cells?
These stem cells are made when two Gametes make a zygote. This zygote divides by Mitosis, and the group of cells that is formed are embryonic stem cells. They can form any type of cell
What is therapeutic cloning?
Embryo created to match patient’s genes.
What is diffusion?
Movement of particles from high to low concentration.
What is a concentration gradient?
Difference in concentration affecting diffusion rate.
What is gas exchange?
Oxygen and carbon dioxide movement in lungs.
What factors affect diffusion?
Concentration, temperature, and surface area influence rate.
What is passive transport?
Movement of substances without energy usage.
What is cell membrane permeability?
Rate that small molecules can diffuse across cell membranes.
What is urea transport?
Urea moves from liver to blood for excretion.
What are the issues in stem cell research?
Ethical concerns and differentiation control challenges.
What are meristems in plants?
Stem cells in plants found in growth tips.
What is cloning plants?
Using meristems to replicate desirable plant traits.
What is the surface area to volume ratio?
Comparison of organism’s surface area to its volume.
What are alveoli?
Air sacs in lungs for gas exchange.
What are villi?
Projections in small intestine for nutrient absorption.
What are gill filaments?
Structures in fish gills for oxygen absorption.
What are stomata?
Pores in leaves for gas exchange.
What are guard cells?
Cells that regulate stomata size.
What is osmosis?
Water movement through a partially permeable membrane.
What is water potential?
Tendency of water to move, influenced by concentration.
What is an isotonic solution?
Equal concentration inside and outside the cell.
What is a hypertonic solution?
Lower concentration of water outside the cell, causes cell to shrink.
What is a hypotonic solution?
Lower concentration of water outside, causes cell to swell as water moves into the cell by diffusion
What is turgor pressure?
Pressure from water in plant vacuoles.
What is plasmolysis?
Cell membrane pulls away from cell wall or Plant cells lose water
What is active transport?
Movement against concentration gradient, requires energy.
What is a concentration gradient?
Difference in concentration across a space.
What is respiration?
Process of converting glucose into energy.
What are mineral ions?
Essential nutrients absorbed by plant roots.
What is gas exchange?
Process of swapping oxygen and carbon dioxide.
What are capillaries?
Small blood vessels for nutrient and gas exchange.
What is the diffusion pathway?
Distance molecules travel during diffusion.
What is a steep concentration gradient?
Large difference in concentration enhancing diffusion rate.
What do animal and plant cells have in common?
Both have a nucleus, cytoplasm, mitochondria, ribosomes, and a cell membrane.
What additional structures do plant cells have?
Plant cells also have a vacuole, a cell wall, and chloroplasts.
What is the function of the nucleus?
Stores DNA of the cells and controls the cell’s activities.
What is the function of the cell wall?
Supports the cell and gives it a rigid structure.
What is the function of the cell membrane?
Controls what goes in and out of cells.
What is the function of mitochondria?
Site of anaerobic respiration.
What is the function of chloroplasts?
Contain chlorophyll so it is the site of photosynthesis.
What is the function of ribosomes?
Site of protein synthesis.
What is the function of vacuoles?
Stores cell sap.
What is the function of cytoplasm?
Jelly-like substance where all chemical reactions take place.
What distinguishes prokaryotic cells from eukaryotic cells?
Prokaryotic cells have no nucleus and no membrane-bound organelles.
What structures do prokaryotic cells have?
They have cytoplasm, plasmids, a cell wall, a cell membrane, ribosomes, DNA strands, and a flagellum.
What type of DNA do eukaryotic cells have?
They have linear DNA organized as chromosomes found in the nucleus.
What type of DNA do prokaryotic cells have?
They have a circular loop of DNA found in the cytoplasm called plasmids.
What is the first step to use a microscope?
Place slide on the stage.
What should you do after placing the slide on the stage?
Use clips to hold the slide in place.
Which objective lens should you start with when using a microscope?
Use the lowest objective lens.
What should you do while looking from the side when using a microscope?
Apply coarse focus slowly.
What should you do when the objective lens is almost touching the slide?
Stop turning the coarse focus.
What should you do after looking through the eyepiece?
Turn the coarse dial slowly until cells come into focus.
What is the next step after focusing the cells?
Turn the fine focus to get a cleaner image.
What should you do after achieving a clear image?
Repeat steps 3-8.
How do you calculate total magnification?
Total magnification = Eyepiece lens x Objective lens.
What is the magnification equation?
Magnification = Image size / Actual size.
What are the steps for the Culturing Bacteria Practical?
Get an Inoculating loop and sterilise it by placing it in a Bunsen burner until it’s red hot.
Get the bacterial culture bottle and remove the lid, then sterilise it by holding the neck near the flame. This moves air out of the bottle and prevents other microorganisms from entering the bottle and containing the bacterial solution.
Place the sterilised Inoculating loop in the flask containing the bacterial culture.
Flame the neck of the bottle and replace the cap.
(Petri Dish) Lift the dish slightly( so that microorganisms from the air cannot enter the petri dish), make zig zag streaks with the loop and close the lid quickly. Store it upside down in a incubator, with the max temperature at 25 degrees.
Sterilise the Loop again and disinfect all work surfaces
Why do we set incubators at school no higher than 25 degrees?
To stop harmful bacteria from growing
Why do heat the inoculating loop with a bunsen burner?
To sterilise it.
Is binary fission asexual reproduction?
Yes
