Plant + Animal + Specialised cells Flashcards
(15 cards)
What makes up a plant cell?
- Nucleus=
BRAIN of the cell and controls cell processes. Contains the DNA. - Cell membrane=
Controls the MOVEMENT of substances in and out the cell. - Cytoplasm=
Where CHEMICAL REACTIONS happen and its maintains the cell SHAPE. - Mitochondria=
Produce ENERGY through cellular RESPIRATION. - Cell wall=
Contains CELLULOSE to provide strength and SUPPORT the cell. - Vacuole=
Contains CELL SAP and it keeps the cell FIRM. - Chloroplasts=
Found in LEAF + STEM and contains CHLOROPHYLL which is where PHOTOSYNTHESIS occurs. - Ribosomes=
Tiny structures responsible for PROTEIN SYNTHESIS.
What makes up an animal cell?
- Nucleus=
BRAIN of the cell and controls cell processes. Contains the DNA. - Cell Membrane=
Controls the MOVEMENT of substances in and out the cell. - Cytoplasm=
Where CHEMICAL REACTIONS happen and its maintains the cell SHAPE. - Mitochondria=
Produce ENERGY through cellular RESPIRATION. - Ribosomes=
Tiny structures responsible for PROTEIN SYNTHESIS.
How are plant + animal cells different?
- Plant cells contain a CELL WALL, LARGE CENTRE VACUOLE and CHLOROPLASTS but animal cells don’t.
- Animal cells have NO CELL WALL, NO CHLOROPLASTS and SMALLER VACUOLE (If present).
What are bacterial cells?
Like animal and plant cells, they have a cell membrane but don’t have a nucleus which makes them prokaryotic cells.
What does a bacterial cell contain?
- a loop of chromosomal DNA in the cytoplasm=
carries most of the bacterial genes. - ribosomes=
tiny structures that make proteins. - some have plasmid DNA=
contain additional genes that are not found in chromosomes. - cell wall=
for protection but its made of different substances to plant cells. - cell membrane
- some have a flagellum=
to help them move.
How is an egg cell adapted to its function?
- contains nutrients in the cytoplasm to supply the embryo.
- haploid nucleus so it can fuse with another haploid nucleus from the sperm to form a diploid zygote.
- after fertilisation, the cell membrane changes so no more sperm can enter.
How is a sperm cell adapted to its function?
- tail for swimming to the egg for fertilisation.
- lots of mitochondria around the base of the tail to release energy so the sperm can swim to the egg.
- haploid nucleus to fuse with the egg.
- acrosome contains enzymes to digest its way through the egg cell membrane.
How is the shape of a root hair cell adapted to its function?
It has a long thin hair which increases the surface area for diffusion
What is diffusion?
Molecules move from a high conc of dissolved molecules (concentrated solution) to a low conc of dissolved molecules (dilute solution) through a partially permeable membrane.
- it is used to move oxygen into cells and to remove CO2.
What is active transport?
Molecules move from a low conc of dissolved molecules to a high conc of dissolved molecules through a partially permeable membrane and it requires energy from respiration.
- there is a net movement against the gradient.
- it makes it possible for cells to absorb ions from very dilute solutions.
What are stem cells?
They are cells that can divide to produce many types of cell.
What are embryonic stem cells?
They are taken from embryos at a very early stage of division.
ADVANTAGES:
- they are easy to extract.
- produce any type of cell.
DISADVANTAGES:
- embryo is destroyed and some people think that embryos have a right to life.
USES:
- replacing or repairing brain cells to treat people with Parkinson’s.
- replacing damaged cells in the retina.
- growing new tissues in a lab to use for transplants or drug testing.
What are adult stem cells?
They are found in differentiated tissue, such as bone or skin and they divide to replace damaged cells.
ADVANTAGES:
- not an ethical issue.
- will not cause rejection from the body if taken from person who needs to be treated.
DISADVANTAGES:
- produce only a few type of cell.
USES:
- treatment for leukaemia
- potentially growing new tissues that are genetically matched to the patient.
What is the advantage + disadvantage of all stem cells?
ADVANTAGE:
- they replace faulty cell with healthy cell so person will be well again.
DISADVANTAGE:
- stem cells may not stop dividing and so cause cancer.
What are meristems?
They are what plants have in rapidly growing parts of the plant, e.g. tips of roots and shoots. These cells can divide to produce any kind of plant cell.
