B1 - Cell Biology - Combined Flashcards
Cell types
What are the two main cell types?
Eukaryotic and prokaryotic
Cell types
Which is bigger - eukaryotic or prokaryotic?
Eukaryotic - 5 - 100 micrometers
Prokaryotic inky 0.2 - 2 micrometers
Cell types
What organelles do both eukaryotic and prokaryotic cells have in common?
Ribosomes
Cell membrane
Cytoplasm
Cell types
What are 3 examples of eukaryotic cells?
Animal, plant, fungi cells
Cell types
What organelles to eukaryotic cells only sometimes have?
Cell wall
Chloroplasts
Permanent vacuole
Cell types
In a eukaryotic cell - where is the DNA?
In the nucleus
Cell types
Eukaryotic cells have ___ bound organelles
Membrane
Cell types
What organelles to prokaryotic cells only sometimes have
Capsule and flagella
Cell types
Where is DNA stored in prokaryotic cell?
Single loop of loose DNA and plasmids
Cell types
True or false: prokaryotic cells have no membrane bound organelles
True
Cell types
What is an example of a prokaryotic cell
Bacterial cell
Organelles
What is the function of the nucleus
Contains the genetic material of the cell and controls its activities
Organelles
What is the function of the cytoplasm
It is the area where most chemical reactions occur
Organelles
What is the function of the cell membrane
It controls the substances that go in and out of the cell
Organelles
What are mitochondria?
Sit of (aerobic) respiration whereby energy is released (NOT PRODUCED)
Organelles
What are ribosomes
Site of protein synthesis
Organelles
What is the permanent vacuole?
Filled with cell sap to keep the cell turgid (hard and rigid)
Organelles
What does turgid mean?
Hard and rigid
Organelles
What does the cell wall do
Strengthens and supports the cell
Organelles
What is the cell wall made of in plant cells
Cellulose
Organelles
What are chloroplasts
Site of photosynthesis
Organelles
What do chloroplasts contain that allows them to absorb light energy for photosynthesis?
Chlorophyll
Organelles
What pigment does chlorophyll have?
A green pigment
Organelles
What are plasmids?
Small rings of DNA loose within the cytoplasm
Organelles
True or false: plasmids can be shared between cells, passing anti-biotic resistant genes to each other
True
Organelles
What is the capsule?
Sticky layer covering the cell wall
Organelles
What does the capsule help the cell to do
Stick to surface and avoid immune responses
Organelles
What is the flagella?
Long threadlike structure which enables the cell to move at speed
Organelles
What is the single loose ring of DNA
Single, circular loop of DNA loose within the cytoplasm
Diffusion
What is diffusion?
The net movement of molecules from an area of high concentration to an area of lower concentration, down a concentration gradient
Diffusion
True or false: diffusion is an active process?
False : it is passive
Diffusion
What is a passive process?
One which doesn’t require energy
Diffusion
What is the concentration gradient?
Difference in concentration between two areas
Larger difference = faster rate of diffusion
Diffusion
As molecules diffuse the concentration gradient increases/decreases?
Decreases
Diffusion
What are 4 adaptions to increase rate of diffusion?
Increase temperature
Increase concentration gradient
Increase surface area
Reduce diffusion pathway distance
Diffusion
What are the two adaptions of the red blood cell for diffusion?
Biconcave shape - large surface area
Thin membrane - short diffusion pathway
Diffusion
What are the three adaptions of the villi for diffusion
Curved - large surface area
Thin membrane and close blood vessels - short diffusion pathway
Efficient blood supply - maintains steep concentration gradient
Diffusion
True or false: the adaptions for diffusion are the same in the villi as the alveoli and gills of the fish
True
Diffusion
What are the three adaptions of the root hair cell for diffusion?
Long protrusion (large surface area)
Thin membrane (short diffusion pathway)
Well ventilated to maintain steep concentration gradient
Diffusion
What are the three adaptions of plant leaves for diffusion?
Well ventilated to maintain steep concentration gradient
Large surface area - curved
Short (non existent) diffusion pathway with stoma
Stem cells
True or false: sperm cells are produced by differentiation
False: they are not produced by differentiation
Stem cells
In animal/plant cells most differentiation occurs in the womb whereas in animal/plant cells differentiation occurs throughout the life
Animal then plant
Stem cells
What are 4 examples of plant cells which are specialised
Root hair cells
Xylem
Phloem
Palisade
Stem cells
What are 3 examples of specialised animal cells
Nerve cells
Red blood cells
Muscle cells
Stem cells
What is differentiation?
The process by which cells become specialised
Stem cells
What is the potency of the stem cell
How much stuff the cell can become
Stem cells
What is a pluripotent stem cell
A stem cell that can differentiate into any specialised cell type
Stem cells
What is a Multipotent stem cell?
Stem cell that can differentiate into restricted numbers of specialised cell types
Stem cells
What is an example of a Multipotent stem cell?
Skin stem cells
Stem cells
What is enucleation?
When a nucleus is removed and discarded
Stem cell
What are specialised cells?
Cells which are adapted to perform a specific function
Stem cells
Why are the two key stem cells for animals?
Embryonic and bone marrow stem cells
Stem cells
The embryonic/bone marrow stem cell is pluripotent whereas the embryonic/bone marrow stem cell is Multipotent
Embryonic then bone marrow
Stem cells
Which type of stem cell is found in the embryo and umbilical cord
Embryonic
Stem cells
Which type of stem cell is found in bone marrow
Bone marrow stem cell
Stem cells
Which type of stem cell is found in adults
Bone marrow stem cell
Stem cells
Which type of stem cell is not found in adults
Embryonic
Stem cells
What type of specialised cells can bone marrow stem cells differentiate into
Blood cells such as White and red blood cells
Stem cells
Why are embryonic stem cells useful
They differentiate into different specialised cells for the development of the foetus
Stem cells
What is the main stem cell found in plants
Meristem
Stem cells
Is meristem pluripotent or Multipotent
Pluripotent
Stem cells
True or false: the meristem cells do not exist throughout the plants life
False
Stem cells
Where are meristem cells found
Tips of roots and shoots
Stem cells
How do you cut a plant to reproduce it (3 steps)
Cut plant
Dip in rooting powder (regrowth hormone)
Plant it
Stem cells
What is the method for the use of embryonic stem cells in medical treatment called?
Therapeutic cloning
Stem cells
What is the first stage of therapeutic cloning
Fertilised human egg is enucleated
Stem cells
What is the second step in the method for therapeutic cloning
Cell is taken from patient and nucleus is removed (not enucleated as nucleus is not discarded)
Stem cells
What is the third stage of therapeutic cloning
Patients nucleus is implanted into enucleated cell
Stem cells
What are the 4th and 5th stages of therapeutic cloning
Cell is stimulated to divide and forms an embryo
Cells are separated to be cultured and developed into different tissues
Stem cells
Give 2 ethical concerns with the use of embryonic stem cells in medical treatment
Destroys a potential human life
Embryo could have rights not to be medically tampered with
Stem cells
What are 2 scientific concerns with the use of embryonic stem cells in medical treatment?
Process could transfer infection
Process could cause cancer in patient
Stem cells
What are three arguments for the use of embryonic stem cells in medical treatment
Can cure disease
Better not to waste (readily available)
Painless
Stem cells
What are two diseases which can be cured using embryonic stem cell treatment (therapeutic cloning)
Diabetes and paralysis
Stem cells
How is bone marrow extracted from donors
Needle sucks bone marrow from pelvic bone
Stem cells
What is one problem with the donation of bone marrow stem cells
Patient must have exact tissue match to donor and there is currently a shortage
Stem cells
What are the three risks of bone marrow stem cell treatment
Could be rejected
Patient may depend on immunosuppressants for the rest of their lives
Infection could be transferred
Stem cells
What is one disease which can be treated with bone marrow stem cells
Leukaemia (survival rate 70%)
Stem cells
What are orders of magnitude
A logarithmic scale of measurement base 10 (that isn’t gcse definition)
Eg 300mm is 10 to the power 2 times bigger than 3 mm so is 2 orders of magnitude larger
Osmosis
What is osmosis
The net movement of water from an area of higher water concentration to an area of lower water concentration, through a partially permeable membrane
Osmosis
Is osmosis a passive or active process
Passive
Osmosis
Is higher water concentration a dilute solution or a concentrated solution?
Dilute
Osmosis
Pure (distilled) water has the highest/lowest water concentration
Highest
Osmosis
The cytoplasm has a low/high water concentration because it has low/high amount of solutes
Low then high
Osmosis
If osmosis causes water to enter and animal cell that cell will….
Burst
Osmosis
If osmosis causes water to leave an animal cell it will
Shrink
Osmosis
If osmosis causes a plant cell to gain water it will become….
Turgid
Osmosis
If osmosis causes water to leave an animal cell it will…
Be flaccid
Osmosis
What does an isotonic solution mean?
The concentration of the cell and solution surrounding are equal (there will be no net osmosis)
Microscopy
What is microscopy
Investigation using a microscope
Microscopy
What is magnification
How many times bigger the image is compared to the real object
Microscopy
What is resolution?
The ability to distinguish between two points