Plant cells Flashcards
Plant cell wall
- Maintains cell shape
- Controls rate and direction of growth
- Protects against pathogens and environment
- Controls cell to cell interactions
- 3 layers: hemicellulose, cellulose, pectin
How do plant cells expand?
New material is deposited in cell wall, enzymes break connections in cell wall and expand
What is a secondary cell wall?
Deposited between primary wall and plasma membrane to support, strengthen and protect
What is secondary thickening?
Cutin, lingin, cellulose, suberin
Why is secondary thickening needed?
For xylem and phloem, pod shattering, anther dehiscience and abscission
What is anther dehiscience?
Secondary thickening in the endodermis layer in the anther
What is abscission?
Process to remove plant organs (leaves and petals) to form a protective layer
Root hairs
- Comprised of a single cell and is from the epidermis
- Increases surface area and thin cell wall for uptake of water and nutrients
- Root cap to protect and guide the root
Xylem
Conducts water passively
Phloem
Actively transports sugars and amino acids
What are companion cells?
Like plant cells but contains more plasmodesmata, ribosomes and mitochondria
What is trichome?
Small hair growing from the epidermis
Name all plastids
- Chromoplasts (pigments)
- Leucoplasts (energy)
- Elaioplasts (lipids)
- Proteinoplasts (protein)
- Amyloplasts (starch)
- Chloroplasts (genetic material)
- Grana (photosynthesis)
- Stroma (carbon dioxide fixation)
What is the vacuole?
Membrane bound organelles filled with sap which take up most room in a plant cell and is acidic
Function of vacuole
- Cell homeostasis
- Detoxification
- Storage of tissues
- Pigmentation
