Plants Flashcards
Moss- biggest buffer of carbon on earth.
Peat moss= carbon sink
Has to be kept in damp/wet conditions so sperm can swim to fertilise
Mosses and plants have the same process
SPOROPHYTE(2n) —>(meiosis)—> SPORES(1n)—>(germinates)—> GAMETOPHYTE(1n)—>(mitosis)—>OVUM AND SPERM(1n)—>(fertilisation)—>SPOROPHYTE
FLOWERING PLANTS: •very important for water n carbon cycles •plants are sporophytes •megaspores in ovule(f) •microspores in pollen grains(m)
•chemical recognition when pollen of same species of plant lands on stigma (prevents cross pollination)
AFTER FERTILISATION:
•male gamete fertilises egg cell= embryo
- embryo in ovule —> ovule becomes a seed
- ovule in ovary —> ovary becomes a fruit
TRANSPIRATION:
•plant cells are rigid =made of cellulose
•if a plant cell is short of water it becomes plasmolysed, the contents of the cell shrink away from cell wall
WATER POTENTIAL:
- ¥= ¥s + ¥p + ¥m
- ¥s= solute potential (water moves by osmosis in response to solutes)
- ¥p= pressure potential (water moves because of hydrostatic pressure)
- ¥m= matric potential (presence of matrix means high SA)
- pure water= 0 (total ¥)
- closer to 0 the ¥ (more positive), the more water there is (more diluted)
- e.g. -15 is more positive than -67
- drought= ¥s is very negative as water drawn out of the cell so plasmolysis occours
- OSMOSIS= water from low ¥s to a high ¥s
ORGANELLES:
•mitochondria= aerobic respiration, ATP
•Golgi body= protein and lipid modification
•RER= protein synthesis
•SER= lipid synthesis and transportation
•peroxisome= vesicles containing enzymes + chemicals involved in oxidising molecules
•vesicles= transport molecules
•nuclear envelope= pores which allows molecules to move in and out
•nucleus= storage and replication of DNA
•nucleolus= where RNA synthesis happens
•Lysosome= vesicle containing enzymes which digest molecules
- organelles only in plant cells= chloroplasts, cell wall, large central vacuole
- only in animal cells= centrioles
