Cells ( transpiration ) Flashcards
Types of cell
Prokaryotic and eukaryotic
Prokaryotic cells
Bacteria
Has a cell wall and cell membrane and cytoplasm
No nucleus ( they are plasmids)
What do Eukaryotic cells contain
Plants - chloroplast ( contain chlorophyll), vacuole , cell membrane
Animal and plants - mitochondria for aerobic respiration, ribosomes for protein synthesis
Equation for magnification
= size of image / size of real object(given in q )
Mitosis process
- cell has to get bigger and make more organelles and the dna replicates
- chromosomes pulled to either end of cell
- cytoplasm divides to create daughter cells which are genetically identical
What is mitosis used in
Asexual reproduction and growth
Meiosis process
- dna replicates like In mitosis
- homologous chromosomes pair up
- divide twice to produce 4 daughter cells ( gametes, eggs/ sperm)
- not genetically identical
- in the daughter cells you get half the number of chromosomes as the original cell
What’s diffusion
Movement of a substance from a high to low concentration
How would you make the rate of diffusion faster ?
Increase Concentration and temp
Larger SA , eg small intestines( villi) , alveoli in lungs
Osmosis
Movement of water from a dilute to concentrated solution across a semi-permeable membrane
Active transport
Particles being moved from low to high concentration
Needs energy to be released via respiration
What’s a stem cell
Undifferented cell of an organism which is capable of giving rise to many more cells of the same types
Where are stem cells found
Embryos
Adult stem cells - bone marrow
Tips of shoots - meristems
Problems and advantages with getting stem cells from embryos
Ethical problems
Can be used in therapeutic cloning- treats paralysis/diabetes- has the same genes as patient
What does a root hair cell do
Its and extension of of the cytoplasm and increase the surface area
What’s the xylem
Water travels up this
How is the water taken up the xylem
When the water evaporates out the stomata a sucking force is applied this moves the water up
Transpiration practical
2 leaves , 1 with Vaseline on the top and one on the bottom of the leaf
Very little mass in lost in the leaf with Vaseline on the bottle. As the stomata is blocked ( also won’t wilt)
The leaf with Vaseline on the top will begin to wilt
How would you increase the rate of transpiration
- hot
- wind
- dry
How do you measure the rate of transpiration
With a potometer
