B2- Cell Specialisation Flashcards
Why do multicellular organisms need specialized cells?
Because not all the cells in the organism will have the same access to all the required resources.
What would happen without specialization in multicellular organisms?
The organism would not act as one coordinated organism but as a collection of independent cells.
What is the primary function of animal stem cells?
Animal stem cells help specific tissue with regeneration and repair.
This emphasizes the role of stem cells in maintaining tissue health.
Do animal stem cells have the ability to differentiate into any type of animal cell?
No, animal stem cells tend to be specific to the tissue.
For example, blood stem cells can only differentiate into blood cells.
What type of cells can blood stem cells differentiate into?
Blood stem cells can only differentiate into blood cells.
This specificity highlights the limited differentiation potential of certain stem cells.
Fill in the blank: Animal stem cells tend to be specific to the _______.
tissue
True or False: Animal stem cells can regenerate any type of tissue.
False
Animal stem cells are typically limited to specific types of tissue.
Where are plant stem cells located?
In the meristems of the plant
What is the primary function of plant stem cells?
To differentiate into all types of different specialised plant cells
Name two types of specialised plant cells that stem cells can differentiate into.
- Root hair cells
- Palisade mesophyll cells
Can plant stem cells differentiate into any type of plant cell at any time?
Yes
What do plant stem cells enable for the plant?
Continuous growth throughout its life
What is the primary function of root hair cells?
Absorb water from the soil for use in photosynthesis and other metabolic reactions.
Root hair cells play a crucial role in plant hydration and nutrient uptake.
What types of minerals do root hair cells absorb?
- Magnesium
- Nitrogen
- Sulfur
- Phosphorus
- Potassium
These minerals are essential for various physiological functions in plants.
function of mitochondria on root hair cell
large numbers of mitochondria are needed to provide energy for active transport of solutes into the cell sap to lower the water potential.
thin cell wall in root hair cell
provides short diffusion path for water and mineral ions
long hair like extensions in root hair cell
increases surface area for absorption of mineral ions and water
no chloroplast in root hair cell
not needed, gives more room of water storage and the large amount of mitochondria needed
membrane permeability in root hair cell
membrane is selectively permeable to allow water mols and mineral ions in to the cell easily due to specific channels in membrane which allow for the diffusion of molecules form an area of high concentrations (soil) to an area of low concentrations (cell). this process is called facilitated diffusion due to the use of the protein channels in the membrane.
movement of water in root hair cell
Water enters the cell sap by
osmosis through the
tonoplast membrane.
Osmosis: definition
Osmosis is the movement of water through a partially
permeable membrane from an area of high
concentration of water to an area of low concentration
of water.
water potential in root hair cell
the measure of water’s potential to move from one area to another. pure water has the water potential of 0, so when solutes are added the water potential decreases into a negative values- more solutes added the lower the water potential. the lower the water potential the easier it is for the water to move into the solution through osmosis. so to draw water into the cell sap, the root hair cell actively lowers the water potential in the vacuole by actively pumping solutes into the vacuole against a concentration gradient. this process requires energy from mitochondria.
active transport of solutes in root hair cells
Solutes e.g. NaCl moved by active transport into cell sap
to lower its water potential and draw water in. Energy is
needed for this process which is why there are a lot of
mitochondria in root hair cells
arrangement of cells in palisade mesophyll cell
The cells are packed closely together
to provide a continuous layer for
photosynthesis and maximize light absorption
cell position in pallisade mesophll cells
Palisade mesophyll cells are close to the surface of
the leaf to allow a short diffusion pathway for
carbon dioxide.
cell wall - pallisade
Cell wall is clear to allow light in
more easily for photosynthesis. They
also keep the cell rigid, so the leaf is
kept at right angles to sun.
chloroplast - pallisade
Chloroplasts are needed to use
the energy from sunlight to react
carbon dioxide with water to
produce carbohydrates like
glucose. There are large number
of chloroplasts in palisade
mesophyll cells.
location of chloroplasts
Chloroplasts can move within
the cell using the cytoskeleton so
more will migrate towards the
surface of the leaf during dull
weather but move away to avoid
damage if the sun is bright.
large vacuole - pallisade
Chloroplasts can move within
the cell using the cytoskeleton so
more will migrate towards the
surface of the leaf during dull
weather but move away to avoid
damage if the sun is bright.
function of the sperm
A sperm is a male gamete (sex cell). Its main function is to carry genetic material to the ovum (female gamete) – fertilisation. In order to do this, it
needs to swim a long distance.
acrosome - sperm cell
found in the head of the sperm, specialised vesicle containing enzymes needed to break down the eggs membrane to allow for fertilisation by the sperm
mitochondria- sperm
found in the mid - section of the sperm in a spiral pattern bcs sperm needs lots of energy to be able to swim form the cervix to the fallopian tube to fertilise egg.
What is the primary function of palisade mesophyll cells?
Most photosynthesis takes place in these cells
Photosynthesis captures energy from sunlight to build molecules like glucose.
What is the purpose of photosynthesis?
To capture the energy from sunlight to build molecules such as glucose from carbon dioxide and water
Photosynthesis is essential for converting solar energy into chemical energy.
Fill in the blank: The palisade mesophyll cells are primarily responsible for _______.
photosynthesis
undulopodium
tail/falgellum of sperm and required for mobility
haploid nucleus
located at the head of the sperm and contains only half the number of chromosomes (23 for humans) and no pairs of chromosones.so when it fertilises the resulting zygote will have the correct amt of chromosomes(46 in humans)
haploid nucleas- egg
A sperm is a male gamete (sex cell). Its main function is to carry genetic material to the ovum (female gamete) – fertilisation. In order to do this, it
needs to swim a long distance.
cytoplasm and organelles - egg
Eggs cells have a large amount of
cytoplasm and associated organelles. It
contains nutrients that support the
development of the developing zygote
after fertilisation.
Large numbers of mitochondria are
needed to provide the energy required
after fertilisation.
zona pellucida - egg
The zona pellucida is a special coat outside
of the egg cell membrane. It is made up of
glycoprotein filaments. After one sperm
has entered the egg, it becomes
impermeable preventing other sperm from
entering (polyspermy). After fertilisation,
the zona pellucida protects the developing
embryo until it is about to implant into the
endometrium – this is called hatching.
corona radiata
The corona radiata consists of two or three
layers of cells from the follicle. They are
attached to the zona pellucida. Its main
function is to supply vital proteins to the
egg cell.
fucntion of red blood cells
Red blood cells carry oxygen from the lungs to wherever it is needed in the body. The oxygen is needed for cellular respiration to provide the energy for
the cells’ needs. This reaction takes place in the mitochondria of the cells
haemoglobin - red blood cell
Red blood cells carry oxygen from the lungs to wherever it is needed in the body. The oxygen is needed for cellular respiration to provide the energy for
the cells’ needs. This reaction takes place in the mitochondria of the cells
bone marrow
The stem cells for all blood cells, including red blood cells, are in the bone marrow in many
bones including hip bones, vertebrae and skull bones
cell respiration
Glucose + Oxygen —>Water + Carbon dioxide
number of red blood cells
Red blood cells are the most numerous blood
cells and make up 45% of the blood by volume.
There is estimated to be about 5 million red
blood cells per ml of blood. The large numbers
of red blood cells means that the blood can
carry more oxygen.
Membrane: red blood cell
The cell membrane of the red blood cell is very
thin to allow a short diffusion pathway for
oxygen (or carbon dioxide) to enter the cell. It
also gives the cell flexibility to allow it to
squeeze through narrow capillaries.
It has an underlying cytoskeleton that allows
the cell to withstand forces.
Cell flexibility: red blood cell
The shape of the cell and the thin membrane
give the red blood cell flexibility so it can
squeeze through narrow capillaries. This also
ensures the cell membrane is close to the wall
of the capillary to ensure as short a diffusion
pathway as possible.
Organelles: red blood cell
Red blood cells do not contain a nucleus,
mitochondria, rough or smooth ER and
mitochondria. This allows a lot more room in
the cell. This extra space is used to pack in as
many haemoglobin molecules as possible so
each red blood cell can carry as much oxygen as
possible.
biconcave shape- red blood cell
The shape allows a large surface area to volume
ratio so that more oxygen can be absorbed into
the red blood cell.
white blood cell
There are many different types of white blood cell. Together they make up about 1% of the total volume of the blood. They are also made in the bone
marrow. Their main function is to protect the body against infection or cancer. Different types of white blood cell do this in different ways.
neutrophil function
Neutrophils are the most common type of white blood cell. They are involved in non-specific response against infection. They
destroy invading microorganisms but do not give long-term immunity.
lobed nuclease -neutrophil, white blood cell
The lobed nucleus takes up
less room and is flexible
allowing the neutrophil to be
able to squeeze through
small spaces such as through
the capillary walls.
Attraction to
microorganisms: neutrophil, white blood cell
Neutrophils migrate towards
pathogens by chemotaxis –
due to the chemicals they
give out. They can squeeze
out of the blood capillaries
and enter the tissues.
lysosomones - neutrophiles , white blood cells
Neutrophils contain a lot of lysosomes – an organelle containing
destructive enzymes. These are used to destroy the pathogens that have
been engulfed during phagocytosis.
phagocytosis, neutrophil, WBC
Neutrophils can engulf pathogens using the process of phagocytosis. The
pathogens will end up inside the neutrophil inside a vacuole where it
can be destroyed by the neutrophil.
t lymphocytes - WBC
T lymphocytes are made in the bone marrow but mature in the thymus
gland. They are involved in specific immunity.
b lymphocytes- WBC
B lymphocytes are made and mature in the bone marrow. They are also
involved in specific immunity. They produce antibodies.
how t lymphocytes work
T lymphocytes detect cancerous cells or pathogens with the antigen
receptor which is why tissue typing is needed for organ transplants or
blood donations.
Helper T cells release cytokines which regulate other white blood cells.
Cytotoxic T cells release toxins which kill cells that are cancerous.
T cells can produce memory cells which can respond more quickly to a
particular pathogen if it encounters it again.
How B lymphocytes work:
B lymphocytes work by producing antibodies which are specific to
particular pathogens. Antibodies do not directly kill pathogens. They can
cause pathogens to clump together because each antigen can combine
with more than one pathogen. This makes them easier for T cells and
other white blood cells to find and destroy. Antigens also bind to viruses
and prevent them from entering the cells.
When a specific infection is encountered, the specific B cell will divide
rapidly into plasma cells which produce the antibodies and memory cells
which speed the response to future infections by the same pathogen.
both lymphocyte types have
Less cytoplasm
Antigen receptor
