B2 cells Flashcards
Cytoplasm
A jelly like fluid inside the cell in which the organelles are suspended
DNA
Molecule that makes up the genetic material of cells which contains the instructions for making the cell and for all the cell’s functions
Enzymes
Biological catalysts: they speed up many of the reactions that happen in cells such as those involved in respiration
Cell membrane
A semi permeable structure, which controls what enters and leaves the cell
Animal cells contain…
- Cell membrane
- Nucleus
- Mitochondria
- Cytoplasm
Nucleus
Contains genetic material and controls the cells activities
Mitochondria
The ‘powerhouses’ of the cell
Plant cells contain…
- Permanent vacuole
- Chloroplasts
- Cell wall
- Cell membrane
- Nucleus
- Mitochondria
- Cytoplasm
Vacuole
Cell organelle that stores materials such as water, salts, proteins, and carbohydrates
Chloroplasts
Site of photosynthesis
Cell wall
A rigid structure that surrounds the cell membrane and provides support to the cell
Where are ciliated epithelia located
Lines the airways (trachea and bronchi)
Egg cell
Female gamete which is fertilised by a sperm cell to become a zygote (then embryo)
Function of ciliated epithelia
Moves mucus to the trachea and bronchi
Components within an egg cell
- Layer of jelly coat
- Cytoplasm containing yolk (food)
- Haploid nucleus
- Cell surface membrane
Where are egg cells/ova produced and made
They are first produced when the female is developing the uterus and are made in the ovaries
Adaptive feature of jelly coat on egg cells
Prevents more than one sperm from entering the egg cell
Adaptive feature of cytoplasm which contains food storage in egg cells
Helps develop the embryo when the egg is fertilised and it provides enough food until it becomes a placenta
Sperm cell
Male gamete
Components within a sperm cell
- Acrosome which contains digestive enzymes
- Haploid nucleus
- Collar which contains mitochondria
- Flagellum (tail)
Adaptive feature of a long tail/flagellum of the sperm cell
Helps sperm to swim and propel the nucleus towards the egg cell
Adaptive feature of mitochondria contained in the collar of a sperm cell
It produces a lot of energy (atp) which allows the sperm to ‘swim’
Adaptive feature of the enzymes contained in the acrosomes of sperm cells
Helps to penetrate the jelly coat and get to the nucleus of the egg cell
Haploid nucleus
Contains half the genetic information needed for the new zygote (23 chromosomes)
Function of red blood cells (erythrocytes)
Transport oxygen from the lungs to all body cells
Adaptive feature of iron haemoglobin in the RBC
Binds with oxygen in the lungs and carries the oxygen which is released to the body cells to be used for respiration
Adaptive feature of the small size of RBC
They can pass through tiny capillaries
Where are RBC produced
In the bone marrow
Adaptive feature of having no nucleus in RBC
Frees up more room for haemoglobin and maximises the amount of oxygen that they can carry
Adaptive feature of the biconcave/disc shaped of RBC
Gives them a large surface area to volume ratio which allows the cells to absorb oxygen easily
Function of root hair cells
To absorb water and mineral ions from the soil
Adaptive feature of long projections/extensions in the root hair cell
Increases the surface area that the plant can use to absorb water and minerals
Adaptive feature of having no chloroplasts in root hair cells
There is no sunlight underground where the root hair cells are so they do not produce chloroplasts
Function of palisade mesophyll cells
Layer of cells under the upper epidermal of a leaf, which carry out photosynthesis
Adaptive feature of the tall shape of palisade mesophyll cells
Allows them to be packed tightly together near the surface of leaves so that they can absorb as much sunlight as possible
Adaptive feature of many chloroplasts in palisade mesophyll cells
The most photosynthesis is carried out in these cells
Magnification
How much bigger the object under the microscope appears
1 millimetre =
1 x 10^-3m
Name of the lens with the lowest magnification
Objective lenses
Magnification equation
Magnification = image size/actual size
When using a light microscope, what is used to give contrast to the features of the cells to make them visible?
A stain/dye
Microscopes
Used to observe structures within cells (sub-cellular structures)
Function of sperm and egg cells
Used for sexual production in animals
Diffusion
The net movement of particles, from a region of their higher concentration to a region of their lower concentration down a concentration gradient as a result of their random movement
Factors that influence diffusion
- Surface area
- Temp.
- Concentration gradient
- Diffusion distance
Osmosis
The net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentration solution) through a partially permeable membrane
Where do substances move into and out of cells by diffusion and osmosis
Through the partially permeable cell membrane
Relationship between a solution and the concentration of water molecules
A concentrated solution will have a lower concentration of water molecules therefore, the solution has a low water potential (vice versa)
Plasmolysis
Water moving out of a leaf cell so the vacuole shrinks which causes the plant to wilt as the cell can no longer give support to the plant (cell is submerged in a hypertonic solution)
Turgid
Water moving into a leaf cell then the vacuole pushes out (plump) against the cell wall so that the plant is now supported and standing upright
What happens when water moves out of a red blood cell
The RBC becomes crenated
What happens when water moves into a red blood cell
The RBC bursts
Flaccid
Water moving out of a leaf cell so the cytoplasm reduces in volume therefore reducing the pressure on the cell wall (cell is submerged in a isotonic solution)
Isotonic solution
When the water potential and solute concentration are the same both inside and outside the cell
Hypertonic solution
When the environment outside the cell has a higher concentration of the solute than inside the cell (higher water potential inside the cell)
Hypotonic solution
When the solution contains a lower solute conc. and a higher water potential than compared to the cell
