Growth and repair Flashcards
What is meant by growth?
growth= permanent increases in the number of cells or in the mass of size of an organism
what is the problem of measuring mass
water contents of the cells may vary greatly particaully in fungi and plants. In animals will have quantites of facecal material and urine held in the bodoes
what is the problem using linear dimensions
can be very decpetive
What is the best way of meausring growth
dry mass
What is dry mass
the mass of the body if an organism with all the water removed from it
When we have dry mass what does it tell us
it shows the biological materail present
What are growth curves
show growth throughout the life of an organism
why does growth stop in land animals
because size is limited by the weight of the animal and the ability of its musxle to move it against gravity
Where does mitosis occur in plants
meristems
what happens in the meristems
mitosis - after the cells have divided they absorb water into their vacuole and elongate rapidly before the cellouse cell wall becomes rigid
Where is meristem located
behind the tip of the stem or root where the cells continue to divide
Why is mitosis important in the repair and growth
When part of a tissue breaks, then there are cells lost. So, mitosis will create tons of new cells in periods of time to fill the gap and make the tissue bigger again
