maintaining life ch4 Flashcards
why do plants need nitrate ions and magnesium ions ?
Plants require nitrogen in the form of nitrate ions absorbed by the roots to make amino acids, chlorophyll and nucleotides. Magnesium ions are also absorbed by the roots of a plant and are required by the plant as a component of chlorophyll.
describe how water and mineral salts are absorbed from the soil into root hair cells. ?
ust behind the growing tips of roots are thousands of tiny root hairs. These tiny root hairs increase the surface area of the root epidermis and are the main area of osmosis. Each root hair is a single, specialised cell.
Describe how water and mineral salts cross the root to reach the xylem vessels ?
Water can reach the cortex of the xylem vessels via two pathways: Symplast, where water moves between the cytoplasm of neighbouring cells. Apoplast, where water can moves directly through the permeable cell walls and intercellular spaces of neighbouring cells.
How does water move from xylem vessels to the outside of a leaf.
as water moves through the xylem vessels, it carries dissolved minerals salts. This is how these mineral salts are transported from the roots to other parts of the plant.
how do plants use water for cooling ?
when water evapourates it takes heat with it , so when water evapourates from the cell wall of a cell in a leaf it cools the cell.
what is excreation ?
Excretion is defined as the elimination of waste products from the body. It is the process by which waste is removed from the body. Example Urine is excreted from the body through the kidneys.
why do pregnant woman need to eat a balanced diet ?
they need to eat protein to produce new cells for the fetus
they need to eat carbohydrate for a supply of energy
and they should have vitamins and minerals these provide iron and calcuim
why should you not smoke when pregnant
carbon monoxide reduces the amount of oxogen which means the fetus gets less oxogen and cannot respire.
why should pregnant woman check with docters before taking drugs
sometimes drugs you take can affect the way your body works therfore affecting your fetus
