Cell biology Flashcards
What are eukaryotic cells
plant and animal cells
what are prokaryotic cells
bacterial cells
a nucleus containing genetic material is apart of which cell?
animal and plant
a cell wall is a property of what cells?
bacterial and plant
the green pigment in a plant cell is called?
a chloroplast
what does a root hair cell do?
A root hair cell is specialized to absorb water and mineral ions from the soil, essential for the plant’s growth and survival. It also provides structural support.
what does a xylem do?
The xylem is specialized tissue in plants responsible for transporting water and dissolved mineral ions from the roots to the stems and leaves. It also provides structural support.
what does a phloem cell do?
A phloem cell in plants is specialized to transport sugars (mainly in the form of sucrose) and other nutrients made in the leaves during photosynthesis to other parts of the plant.
what properties does a root hair cell have to help it carry out its function?
Long, thin projections: These increase the surface area, allowing more water and minerals to be absorbed.
Thin cell walls: Reduces the distance for water and ion diffusion.
Large vacuole: Helps to store absorbed water and mineral ions.
Mitochondria: Provides energy for active transport of minerals.
what properties does a xylem have to help carry out its function?
Hollow tubes: Made up of dead cells joined end-to-end with no cytoplasm, forming a continuous tube for water flow.
Lignin in cell walls: The walls are thickened with lignin, a substance that strengthens the xylem and makes it waterproof.
No end walls: Continuous column of water can flow easily.
Pits: Small holes in the walls allow water and minerals to move sideways to nearby cells when necessary.
what properties does a phloem cell have to help it carry out these functions?
Flexible and Adaptable Walls
Companion Cells
Sieve Tubes
what is cell differentation
Cell differentiation is the process by which a cell becomes specialized to perform a specific function. This happens as the cell develops and changes its structure and functions, making it suitable for its particular role in the organism.
Why is differentiation important?
It allows the organism to develop a wide variety of specialized cells, which together form tissues, organs, and systems to perform complex biological functions.
what are the pros of an electron microscope?
Uses a beam of electrons instead of light.
Higher magnification than a light microscope (can magnify up to 2,000,000 times).
Higher resolution than a light microscope (can distinguish smaller details, around 0.2 nm).
Can produce detailed images of cell structures (organelles).
Two main types: Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM).
TEM provides 2D images, SEM provides 3D images.
what are the pros of a light microscope?
Can observe living specimens.
Produces color images.
Relatively inexpensive and widely available.
Portable and easy to use.
Magnification of up to x1500.
what are the cons of an electron microscope?
Specimens must be dead due to vacuum and preparation requirements.
Expensive and requires specialized training to operate.
produces black and white images
what are the cons of a light microscope?
Limited magnification compared to electron microscopes.
Lower resolution, limiting detail (up to 200 nm).
Cannot view very small organelles like ribosomes or the internal structure of mitochondria.
what is the magnification formula?
mag=size of image/size of real object
how many chromosomes do humans have?
46
when do chromosomes replicate, before or after mitosis and meiosis?
before
how many parents does asexual reproduction involve?
1
in asexual reproduction are the offspring genetically identical?
yes
in which cells is asexual reproduction common?
bacterial
in which type of reproduction are gametes made?
sexual
in which type of cell reproduction are daughter cells genetically identical, meiosis or mitosis
mitosis
how many daughter cells are made from one in meiosis
4
meiosis has 2 sets of cell division. true or false?
true
in mitosis how does a cell replicate?
In mitosis one set of chromosomes is pulled to each end of the cell and the nucleus divides.
Finally the cytoplasm and cell membranes divide to form two identical cells.
what is a stem cell?
A stem cell is an undifferentiated cell of an organism which is capable of giving rise to many more cells of the same type
what is the function of stem cells in humans
Human stem cells have the ability to differentiate into various types of specialized cells, aiding in growth, repair, and replacement of damaged tissues.
what is the function of stem cells in embryos
Embryo stem cells have the ability to differentiate into any type of cell, enabling them to contribute to the development of different tissues and organs in the body.
what is the function of stem cells in meristems in plants.
Meristem stem cells in plants are responsible for growth and development by continuously dividing to produce new cells for root, stem, and leaf formation.
treatment using stem cells may be used to combat what diseases
diabetes and paralysis.
what is osmosis
Osmosis is the diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
what are the practical risks of the use of stem cells in medical research and treatments.
Risk of infection during procedures.
Possibility of immune rejection by the patient’s body.
Uncontrolled cell division, leading to tumors or cancer.
Ethical concerns related to the use of embryonic stem cells.
Difficulty in directing stem cells to differentiate into the desired cell type.
High cost and technical challenges in stem cell therapies.
what are the practical benefits of the use of stem cells in medical research and treatments.
Can replace damaged or diseased cells, offering potential cures for conditions like Parkinson’s disease or diabetes.
Enable the regeneration of tissues for organ repair, such as in heart disease.
Aid in developing treatments for spinal cord injuries and paralysis.
Allow testing of new drugs on human cells without using animals or humans.
Provide insights into how diseases develop through studying cell differentiation.
Could reduce the need for organ transplants by growing organs in labs.
Offer potential treatments for genetic disorders through gene editing in stem cells.
what are the social issues of the use of stem cells in medical research and treatments.
Ethical concerns about the destruction of embryos to obtain stem cells.
Debate over when life begins and the moral status of embryos.
Unequal access to stem cell treatments due to high costs.
Potential exploitation of donors for embryonic stem cells.
Public misunderstanding and mistrust of stem cell technologies.
Concerns over long-term safety and unforeseen consequences of treatments.
what are the ethical issues of the use of stem cells in medical research and treatments.
Destruction of embryos, which some consider as the destruction of potential human life.
Religious objections to interfering with natural processes.
Concerns over consent when obtaining embryos.
Risk of stem cells being used for unethical purposes (e.g., cloning).
High cost and inequality in access to treatments.
Potential for misuse or unintended consequences in research.
what is diffusion
Diffusion is the spreading out of the particles of any substance in solution, or particles of a gas, resulting in a net movement from an area of higher concentration to an area of lower concentration.
what factors can affect the rate of diffusion?
the difference in concentrations (concentration gradient)
the temperature
the surface area of the membrane.
what adaptation does a single celled organism have to allow sufficient transport of molecules into and out of the cell to meet the needs of the organism.
a relatively large surface area to volume ratio
how are the lungs adapted for gas exchnage?
Large surface area provided by millions of alveoli.
Thin walls (one-cell thick) for a short diffusion distance.
Rich blood supply with many capillaries for efficient gas exchange.
Moist lining in alveoli to allow gases to dissolve for diffusion.
Ventilation maintains a steep concentration gradient for oxygen and carbon dioxide.
how is the small intestine adapted for exchange of materials?
Large surface area due to the presence of villi and microvilli.
Thin walls (one cell thick) for short diffusion distance.
Rich blood supply to maintain a steep concentration gradient.
Lacteals to absorb fatty acids and glycerol.
Muscular walls to mix contents and maintain a flow of nutrients.
how are gills in fish adapted for exchange of materials?
Large surface area provided by gill filaments and lamellae.
Thin membranes to minimize diffusion distance.
Rich blood supply to maintain a steep concentration gradient.
Counter-current flow of blood and water for efficient oxygen absorption.
Constant flow of water over the gills to ensure fresh oxygen is available.
how are leaves in a plant adapted for exchange of materials?(5)
Large surface area to maximize gas exchange.
Thin structure to minimize diffusion distance.
Stomata to allow gases (CO₂, O₂) to diffuse in and out.
Guard cells control the opening and closing of stomata.
Air spaces in the spongy mesophyll for efficient gas diffusion.
how can you increase the effectiveness of an exchange surface
having a large surface area
a membrane that is thin, to provide a short diffusion path
(in animals) having an efficient blood supply
(in animals, for gaseous exchange) being ventilated.
how are roots in a plant adapted for exchange of materials?(4)
Root hair cells with a large surface area for water and mineral absorption.
Thin walls of root hair cells to reduce diffusion distance.
Mitochondria in root hair cells for active transport of minerals.
Extensive branching network for increased absorption efficiency.
what is active transport
Active transport moves substances from a more dilute solution to a more concentrated solution (against a concentration gradient).
what is required for active transport?
energy from respiration
what does a plant require for healthy growth
ions
in active transport where are mineral ions absorbed
root hair cells
active transport allows what molecules to be absorbed from lower concentrations in the gut into the blood which has a higher concentration
sugar
what are sugar molecules used for?
cell respiration
what are the differences between active transport, diffusion and osmosis
Diffusion:
Movement of particles from high to low concentration.
No energy required (passive process).
Occurs in gases and liquids.
Osmosis:
Movement of water molecules from high to low concentration.
Through a selectively permeable membrane.
No energy required (passive process).
Active Transport:
Movement of particles from low to high concentration.
Requires energy (ATP) for the process.
Can occur against a concentration gradient.
what is translocation
Translocation is the process by which food (mainly sugars), primarily in the form of sucrose, is transported through the plant from the leaves (where it is produced by photosynthesis) to other parts of the plant (such as the roots, stems, and growing regions). This process occurs in the phloem vessels.
