B1- CELL BIOLOGY Flashcards
Nucleus
Controls the cell. Contains DNA as chromosomes usually in pairs.
Cytoplasm
Chemical reactions occur here.
Cell membrane
Guardian of the cell- controls what enters and leaves.
Ribosomes
Protein synthesis (making enzymes, hormones, etc)
Mitochondria
Respiration (energy release from glucose)
Chloroplasts
Photosynthesis (Glucose made from light)
Permanent Vacuole
Stores fluid and keeps the cell turgid.
Cell membrane
Strengthens cell, made of cellulose
What are only found in plant cells?
Chloroplasts, Vacuole and cell wall
What is a eukaryotic cell
A plant or animal cell that has a cell membrane, cytoplasm and its genetic material enclosed in a nucleus.
What is a prokaryotic cell
A cell in which the genetic material is not enclosed in a nucleus. Its DNA is found as a loop in the cell and there may be one or more plasmids.
What is a plasmid
A small ring of DNA
What type of cell is a bacterial cell
Prokaryotic cell
How does the size of a prokaryotic cell compare to a eukaryotic cell
much smaller
What is the function of the nucleus
controls the cell
What are the common parts of an animal cell
Nucleus, cell membrane, cytoplasm, mitochondria and ribosomes.
What are the common parts of the plant cell
Nucleus, cell membrane, cytoplasm, mitochondria, ribosomes, chloroplasts, cell wall and vacuole.
What is the function of a sperm cell
Carry father’s genetic information and fertilise the egg.
How is a sperm cell adapted
Streamlined shape, nucleus contains 1 set of chromosomes, lots of mitochondria for respiration, contains digestive enzymes.
What is the function of a sperm cell
Transmit electrical impulses around the body.
How is a nerve cell adapted
Long, and lots of dendrites to make connections with lots of other cells
What is the function of a muscle cell
Contract and relax to bring about movement
How is a muscle adapted
lots of mitochondria for respiration
What is the function of the root hair cells
Absorb mineral ions and water from soil
How is a root hair cell adapted
Large surface area and lots of mitochondria for respiration.
What is the function of the xylem
Transport water around the plant
How are the xylem adapted for their function
Few cell structures and so they are dead for more space and supported by lignin.
What are the function of phloem cells
Transport sugars around the plant
How are phloem cells adapted for their function
Few cell structures and supported by companion cells.
What have been the benefits of electron microscopes
Can be used to examine a cell in much finer detail and has led to a better understanding of sub cellular structures.
What are the advantages of electron microscopes
Higher magnification and higher resolution
What is the formula for magnification
Magnification = size of image / size of real object.
How is the cell wall strengthened
Cellulose
Function of the chloroplasts
Site for photosynthesis
Diffusion
- The spreading out of particles from an area of high to low concentration. Substances that move this way are oxygen, carbon dioxide and urea.
What affects diffusion
High concentrations, high temperature and a large surface area make this process faster. Small organisms tend to have large surface area to volume ratios.
Osmosis
Water moves from dilute (lots of water) through a semi-permeable membrane
Active Transport
Uses energy to move from low to high concentration. Used for sugar and minerals
Define magnification
How many times bigger an object is
Define resolution
Ability to see two points clearly
PHLOEM
Conveyor belts of cells that transport sugars, foods, and sap up and down the plant, bidirectional
XYLEM
Long, continuous tubes that water rises up, unidirectional
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