february 2019 unit R2101 past paper Flashcards
what is meant by the leaf petiole?
attaches leaf to stem
contains vascular bundles of xylem and phloem
supports leaf in high wind/rain
allows leaf to track sun throughout day for maximum photosynthesis
what is meant by the leaf lamina?
leaf blade, or flattened surface of leaf
what is meant by the leaf vein?
contains xylem and phloem in leaf vascular bundles
what is meant by the leaf midrib?
main central vein of leaf
smaller veins run off it
runs from leaf base to tip
where are the epidermis and phloem tissues found in a dicot leaf?
epidermis is: layer beneath the cuticle, it is the outer layer of the leaf
phloem: located in the vascular bundles (in spongy mesophyll)
what are two characteristics of the epidermis in a dicot leaf?
guard cells, stomata present, transparent, single layer of cells or hairs
what are the functions of some of the characteristics in a dicot leaf?
reduce/control water loss, enable gas exchange, produce a waxy cuticle, protection from pest/disease/damage.
describe a tap root
derives from radicle, is primary root
describe adventitious roots
roots originate from other plant parts eg; stem or leaves.
can also come from organs eg bulbs/tubers and are usually fibrous
what is the purpose of the root cap?
protects the root from damage as it grows through the soil
produces a lubricant to aid this process
what is the function of the apical meristem?
it is the site of cell division (meristematic)
longitudinal root growth takes place here
what is the function of the cortex in a root tip?
a packing tissue or,
starch storage tissue
what is the function of the root hair?
main area for water and mineral uptake-they also increase the surface area for water uptake.
the hairs are small enough to get in between soil particles
state in words the basic equation for aerobic respiration
oxygen and sugar ——-> carbon dioxide + water+ energy
identify two differences between aerobic and anaerobic respiration
anaerobic respiration takes place without oxygen
“ “ “ “ produces ethanol
“ “ “ “ generates less energy
it takes place in the cytoplasm