b2 Flashcards
(44 cards)
Definition of diffusion
Net movement of particles from region of high to low concentration
factors that affect diffusion
concentration gradient -a higher difference in particles moving means that there’s more particles being diffused
temperature - particles have more energy meaning they diffuse faster
surface area
whats osmosis
net movement of water particles across a partial permeable membrane, from a region of higher to lower water concentration
Diffusion examples in living organisms
Diffusion of toxic particles such as co2 in blood out of blood into lungs to out of body. Diffusion of oxygen out of lungs into blood to distribute out of body
whats active transport
movement of particles, against their concentration gradient, moves from area of low to high concentration. It requires energy from the cell (an active process). It always takes place across a membrane and requires special proteins which transfer particles from one side to another
whats the energy required for active transport and where does it come from
energy comes from cellular respiration, breakdown of glucose in the mitochondria. This energy is stored in ATP, like a battery, takes energy from the cellular respiration to where it is needed.
where is active transport used
it can be used in plants which need to absorb minerals from the soil to survive. root hair cells are adapted and allow the plant to do this, root hair cells use active transport to absorb mineral ions and are adapted to the role by having a large surface area and lots of mitochondria for energy.
what are organelles
the subcellular structures such as the nucleus and ribosomes
what are cells
different combinations of organelles make different cells
e.g. epithelial cell
what’s tissue
a group of similar cells which work together to carry out a common function
e.g. many epithelial cells work together to form epithelial tissue which covers body’s surfaces, e.g. skin
what are organs
groups of different body tissues which work together to form a common function
what’s an organ system
a group of organs which work together to perform a particular function
e.g. organs make up the digestive system
whats an organism
multiple organ systems which work together to form an organism (human)
whats mitosis
the production of new cells
whats the cell cycle
where the cell grows and replicates its information, ready for mitosis to occur
why are new cells required in an organism
growth, repair, development
whats differentiation
a cell changes to become specialised
whats a specialised cell
a cell which has a specific shape or structure to enable the cell to perform the specific role
how is a sperm cell specialised to do its role due to it’s adaptations
flagellum allows the cell to swim
cell is streamlined to make swimming easier
packed with mitochondria for lots of energy to keep swimming
contains half the genetic material, the other half is from the egg cell
what are the two types of stem cells in animals
embryonic stem cells
adult stem cells
what are the key features of stem cells
they can be divided through mitosis
they can be differentiated
whats a zygote and what happens to it
a zygote is a fused sperm + egg cell. It divides for the following few days until it becomes an embryo, after 9 months of development a baby forms.
whats an embryonic stem cell
a cell which can differentiate into any type of cell
whats an adult stem cell
a stem cell which is when a child is now an adult. Adult stem cells can not be differentiated into any type of cell
