Specialised Structures Flashcards
What is the order of cells to multicellular organisms?
cells –> tissues –> organs –> organ systems –> multicellular organism
Compare and contrast Heterotrophs and Autotrophs
Autotroph: automatically gains nutrient
- plants, some algaes
- produce own food through chloroplasts
- turns simple substances –> complex substances
Heterotroph: feeds on others to gain nutrients
- consumes other things for energy
- needs complex substances
- depends on Autotrophs
- tigers, humans, fungi
Outline the cells, tissues, organs, organ systems
cells: group of similar cells create tissue
tissue: group of similar tissues that have particular function make an organ
organ: groups of organs working together with similar function
organ system: many organ systems functioning create a multicellular organism.
Materials required for photosynthesis and role in ecosystems
- carbon dioxide, water and chlorophyll
- produces sugars (glucose) and oxygen
- dependent on this continual flow of energy
- sustain ecosystems
photosynthesis word equation (only a summary! )
Carbon dioxide + water –> Glucose + oxygen
structures in plants used to obtain water and minerals, how surface area to volume ratio affect this: Roots
ROOTS:
- low concentration, receives water through omosis
- water uptake must equal water loss
- roots have hairs on hairs (fractal) increase SA:V, uptake of water increase, branching of roots increase SA
- doesn’t increase V too much
structures in plants used to obtain water and minerals, how surface area to volume ratio affect this: leaves
LEAF:
- structure of leaf compromises these things:
- exposure to maximum photosynthesis surface
- conserve water
- provide exchange of gases for photosynthesis
Shape of leaf:
- eg. pine needles (lots of sunlight, don’t need big leaves)
- eg. large leaf (very little sunlight, maximum sunlight spread out)
Anatomy of a leaf: Cuticule
- cuticle: waxy layer minimise water loss
Anatomy of a leaf: epidermis
- epidermis: skin-like layer under cuticle
Anatomy of a leaf: guard cell
- guard cell: 2 kidney shaped cells around stoma
Anatomy of a leaf: Stomata
- Stomata: hole between guard cells, allow gases in and out of leaf
Anatomy of a leaf: Palisade
- palisade: cell containing chlorophyll, found underneath cuticle and epidermis
Anatomy of a leaf: Xylem and Phloem
- found in vascular bundle in leaf
- xylem: water tube
- phloem: tube for nutrients and glucose
Anatomy of a leaf: spongy mesophyll/parenchyma
- irregular shaped cells
- bulk of soft parts
- communicates with guard cells
Anatomy of a leaf: intercellular space
- spaces between mesophyll
- allows gases in between
