2101 - Cells Flashcards
Cell components
Cell Wall Cell Membrane Nucleus Vacuole Cytoplasm Chloroplast Mitochondrion
Cell Wall
Non- living.
Encloses the cell, gives it shape and support.
Cellulose fibres bonded with Pectin.
Fully permeable, allowing substances to pass through.
Cell Membrane
are Protective structures that help to isolate the cell contents from the environment outside them.
Selectively permeable, allowing some material to pass through but not others.
Cytoplasm
Largely water. Holds other organelles in place.
Enables dissolved substances to move around the cell.
Plasmodesmata
Interconnects adjacent cells, allows communication and transfer of substances between cells.
Nucleus
Control centre of the cells.
Contains DNA & RNA which control the process of cell division.
Mitochondrion
Releases energy through respiration. Large quantities found in meristem tissues.
Energy for growth and repair.
Chloroplasts
Contains Chlorophyll. The organelle in which photosynthesis occurs.
H20, CO2 and light energy into sugars and O2
Vacuole
Storage sac within the cell. Can take up or release excess sugars, water, nutrients and store waste products.
Generate tutor or wilting.
What is a plant Tissue
Group of Cells of similar shape and size which have the same function.
Tissues - Meristematic
Where new cells are produced by cell division. Are responsible for growth at the tips of roots and shoots (Apical - primary growth). Also in the Vascular Cambium (Lateral - secondary growth).
Simple, non-specialised cells.
Growth = cell division and enlargement
Lateral meristems important for propagation with cuttings.
Tissues - Epidermal
Surface protective tissues. (usually one cells thick)
Covers the entire plant and hold it together.
Protects from damage and water loss. Lack chloroplasts. Cell walls contain cutin to form Waxy cuticle, impermeable to water.
Tissues - Transport (Vascular) Xylem
Transport tissue, water and minerals. From roots to stems and leaves.
Passive physical process not active.
Open ended cells which contain lignin. Harden off and die. (transpiration) Only upwards travel.
Tissues - Transport (Vascular) Phloem
Transport tissue, sugars. Contain sieve tubes. Transport food from photosynthesis in the leaves to other parts of the plant. Both directions, active process. Cost the plant energy to use. (involves energy expenditure).
Tissues - Photosynthetic
Found in the leaves, contains Chloroplasts and Chlorophyll.
Tissues - Parenchyma
Packing tissue, unspecialised but can be adapted to specific tasks such as photosynthesis.
(Palisade mesophyll/Spongy Mesophyll)
Fill spaces between other cells and maintain the shape. Can function as a Starch storage tissue.
Cell Growth & Division
Division - Cells divide over and over to produce new, non specialised cells.
Growth - Beyond the growing point Meristem cells slow down rate of division and physically enlarge. Extending Stem or root.
Cell Differentiation
When cells lose their ability to divide they change from Meristem cells to permanent tissue.
Simple Tissues
Epidermis - skin
Parenchyma - packing/bulk
Complex Tissues
Vascular/Transport - Xylem & Phloem
