photosynthesis Flashcards
describe the structure of a leaf
top layer - waxy cuticle - upper epidermis - palisade mesophyll spongy mesophyll lower epidermis Stoma and guard cells
how is the waxy cuticle adapted for photosynthesis
WAXY CUTICLE is waterproof to reduce water loss and clear to allow light through
how are the upper and lower epidermis layers adapted for photosynthesis
UPPER EPIDERMIS has no chloroplasts so that it is clear and colourless so that light can get through
how is the spongy mesophyll adapted for photosynthesis
SPONGY MESOPHYLL have large gaps between cell which increases surface area, allowing for a more rapid diffusion rate
how is the spongy mesophyll adapted for photosynthesis
SPONGY MESOPHYLL have large gaps between cell which increases surface area, allowing for a more rapid diffusion rate
how are the stomata adapted for photosynthesis
they allow gases to diffuse into the air spaces of the leaf which provides a short diffusion distance for carbon dioxide
what do plants require mineral ions for
growth
what do plants need nitrates for
making amino acids (then proteins) and DNA
what do plants need magnesium for
making chlorophyll
what do plants need phosphates for
making nucleic acids (then DNA) and part of cell membrane
what is ATP a source of
energy to be able to carry out life processes
how is ATP released
through cell respiration
how to test for starch in a leaf
iodine solution turning from brown to blue-black
what do plants require mineral ions for
growth
what do plants require magnesium for
chlorophyll
where is bile produced and stored
produced in liver and stored in gall bladder
what does the xylem transport
water and mineral ions
what is homeostasis
the maintenance of a constant internal environment
what are some examples of homeostasis
body water content
body temperature
what is the genome
the entire DNA of an organism
what is a gene
a short section of a molecule of DNA that codes for a protein
where are genes located
in the chromosomes which are contained in the nucleus of the cell
what is one adaptation of the ileum
long and covered with villi for surface area to volume ratio for maximum absorption
what is the role of the pancreas in digestion
produces all three types of digestive enzyme; amylase, protease and lipase
and secretes them in an alkaline fluid into the duodenum
why is the pH of the duodenum slightly alkaline
to neutralise the acidic pH coming out of the stomach
how is food moved through the gut
through peristalsis
how is peristalsis controlled
by circular and longitudinal muscles
what two substances aid the movement of food through the large intestine
mucus - lubrication to reduce friction
dietary fibre - provides the roughage required for the muscles to push against during peristalsis
what muscle contractions occur during peristalsis
