Bio1 - Cell Biology Flashcards
Are Plant Cells and Animal Cells prokaryotic or eukaryotic?
Eukaryotic
Are Bacterial Cells prokaryotic or eukaryotic?
Prokaryotic
Which cells are smallest out of Plant cells, Animal cells, and Bacteria cells?
Bacteria cells.
What is plasmid? What kind of cells is it found in?
Plasmid are rings of DNA. They are found in bacteria cells.
Give the functions of the following
cell parts:
a) Ribosomes
b) Mitochondria
c) Cell membrane
d) Nucleus
a) Ribosomes: Protein synthesis
b) Mitochondria: Where
respiration happens
c) Cell membrane: Controls what
goes in and out of the cell
d) Nucleus: Controls cells activity
(where DNA is kept)
Q. Give the functions of the
following cell parts:
a) Cell wall
b) Vacuole
c) Chloroplasts
d) Cytoplasm
a) Cell wall: Strengthens the cell
b) Vacuole: Contains cell sap
(water, salts and sugars)
c) Chloroplasts: Where
photosynthesis happens
d) Cytoplasm: Where chemical
reactions occur
What is the main molecule that makes up cell walls?
Cellulose
Name 3 cell parts that are found in Plant cells but not in Animal cells.
a) Cell Wall
b) Chloroplasts
c) Vacuole
What is differentiation
The process where a cell become specialised
Many animal cells differentiate an any early stage. How is this different to plant cells?
Many types of plant cell retain the ability to differentiate throughout their life.
In mature animals, what is the main purpose of cell division?
For repair and replacement of cells.
Why is an electron microscope
better than a light microscope?
Better magnification, better
resolution.
Why have electron microscopes
been useful for understanding cell
structure?
Cells can be seen in much finer
detail, therefore scientists now
know more about sub-cellular
structures.
Equation for magnification?
Magnification = (image size) ÷ (real life size)
Describe the stages of mitosis.
• Cell grows and increases
number of sub-cellular
structures (e.g. ribosomes and
mitochondria)
• DNA replicates to form two
copies of each chromosome
• One set of chromosome is
pulled to each end of the cell
and the nucleus divides
• The cytoplasm and cell
membranes divide to form two
identical cells.
Why is cell division by mitosis important?
For growth and development.
How is DNA arranged in a nucleus?
Within chromosomes
What is a stem cell?
An undifferentiated cell capable of becoming a variety of different types of cell.
What are the 2 main places that human stem cells are found?
• Embryos
• Adult bone marrow
Why are embryonic stem cells more useful then stem cells from adult bone marrow?
Embryonic stem cells are capable of changing into a wider variety of cells.
What type of stem cells are used to make blood cells and many other types of human cells?
Cells from bone marrow.
Where are stem cells found in plants?
In the meristem tissue.
Name 2 conditions that stem cells can be used to treat.
• Diabetes
• Paralysis
Give two reasons why someone
might want to use plant stem cells
to produce clones of plants
• Rare species can be cloned to
protect from extinction.
• Crop plants with special
features (e.g. disease
resistance) can be cloned to
produce large numbers of
identical plants for farmers.
By what process do substances move in and out of cells along a concentration gradient?
Diffusion
What is diffusion?
The spreading out of
particles from an area of high
concentration to an area of low
concentration.
Give 2 examples of diffusion occurring in the body.
• Diffusion of oxygen from the lungs into the blood.
• Diffusion of nutrients from the villi (in the small intestine) into the blood.
Give 3 factors that can affect the rate of diffusion.
• Concentration gradient (different concentrations)
• Temperature
• Cell membrane
What 2 things increase the effectiveness of an exchange surface in plants?
• Large surface area
• Thin Membrane
Do single-cell organisms have a fairly large or small surface area to volume ratio?
Large
Explain how the alveoli are adapted for gas exchange.
• Large surface area
• Thin membrane
• Close to efficient blood supply
• Moist lining
• Ventilated (air moves in and
out)
Why do multicellular organisms need exchange surfaces?
They have a relatively small
surface area to volume ratio
so need exchange surfaces to
increase the surface area for
diffusion of substances.
Describe how the small intestine is adapted for exchanging materials.
• Covered in millions of villi
• Villi provide a large surface
area
• Villi have a single layer of
surface cells
• Close network of capillaries
Describe how a plant root is adapted for exchanging materials.
• Root covered in millions of tiny
hairs
• Root hair cells have a large
surface area
• Root hair cells have a thin
surface
Describe how the leaf is adapted for exchanging materials.
• Leaves are flat to increase the
surface area
• Tiny holes (stomata) allows
gases to diffuse in and out.
• Air spaces in leaf expose more
surface of the cells
By what process does water move across cell membranes?
Osmosis
What is osmosis?
The diffusion of water from a
dilute solution (where there
are more water particles) to a
concentrated solution (where
there are less water particles)
through a partially permeable
membrane.
What is active transport?
The movement of substances across cell membrane from regions of lower concentration to regions of higher concentration by the use of energy.
Where does the energy for active transport come from?
Respiration
Give an example of active transport in plant roots.
Mineral ions move from the soil to plant root hairs through active transport.
Describe how molecules can move by active transport in the blood.
Digested food molecules (e.g
sugar) can move from lower
concentrations in the gut to higher
concentrations in the blood.
