transport in plants Flashcards
what is the vascular bundle?
the vessels that transport materials in plantswhat are
the 2 main transport tissues?
xylem and phloem
describe the structure of a xylem vessel
a long, hollow tube made up of dead cells
the inner walls are strengthened by lignin(a form of cellulose)
what is the function of the xylem vessel?
transport water and mineral salts from the roots to the leaves
provide mechanical support
what is the function of the phloem vessel?
translocate sucrose and amino acids from the leaves to other parts of the plant
what elements make up the phloem vessel?
- sieve tube
- companion cell
what is the sieve tube?
a thin wall of living cells separated by sieve plates
(thin lining of cytoplasm and cell organelles plus nucleus are disintegrated)
what is the function of the sieve tube?
carries sucrose and amino acids to parts of the plant
what is the companion cell responsible for?
provides nutrients and helps the sieve tube transport food
what is the structure of the companion cell?
narrow and thin walled
contains many mitochondria (for respiration) and has cytoplasm + nucleus
what allows water transportation?
osmosis, capillary action, root pressure, transpiration pull
what allows the translocation of sucrose and amino acids?
diffusion and active transport
what are the vascular tissues?
the stem and root
what forms the vascular bundle?
xylem and phloem
describe the structure of the stem from the inside
- phloem lies outside of the xylem
- separated by the cambium
- the bundles arranged in the form of rings which surrounds the center (pith)
- cortex out of the pith and both store food (starch)
- coating of cuticle around epidermis layer
describe the structure of the root
- xylem and phloem alternate
- pericycle around the vascular tissues
- endodermis around peri
- cortex lies out
- surrounded by piliferous layer
define translocation
the movement of substances from one place to another
name any translocation study
- aphid studies
- use of radioactive isotopes
