CH 1 Flashcards
Characteristics and function of Parenchyma tissue
Thinnest cell walls
Stores food; starch glucose water
always in turgid state to provide support and maintain shape to herbaceous plants
Characteristics and function of collenchyma tissue
flexible
cell wall not uniformly thickened with pectin and hemicellulose
provide mechanical support and elasticity to plants
Characteristics and function of sclerenchyma tissue
consists of dead cells
cell wall uniformly thickened with lignin
Provide mechanical support to parts of matured plant
Explain Zone of cell division of plant
occur at apical meristem of actively dividing apical meristem cells through mitosis
cells with small vacuoles
when new cells are forming, previously formed cells are pushed to zone of cell elongation
Explain zone of cell elongation of plant
consist of cells that are increasing in size
size of cells increase as water diffuses in through osmosis and nutrients are absorbed
Vacuolation; smaller vacuoles fuses to form one larger vacuole
Explain Zone of cell differentiation of plant
consists of differentiating cells that have reached maximum size
cells differentiate to form permanent cells
cells change shape and structure
Explain process of Primary growth of plants
occur after germination
elongate stems and roots
takes place at apical meristem at shoot and root tips
at shoot tips, leaf primordia and shoot primordia grow forming new leaves and shoots
at root tips, root caps becomes exhausted as it penetrate soils. Meristem cells replace cells of root cap
Explain process of secondary growth of plant
occurs mainly in eudicots
does not occur to non woody plants
occur due to division of lateral meristem cells that consist of vascular cambium and cork cambium
Explain secondary growth at stem
Vascular cambium divides actively through mitosis
cells in cambium ring divide inward to produce new xylem that form secondary xylem and divide outwards to form new phloem that form secondary phloem
walls of xylem are thickened with lignin too provide mechanical support to plants
primary xylem tissue compressed to form stronger wood layer
secondary xylem layer is compressed causes addition on circumference of stem
epidermis of stem stretch and cracks
cork cambium actively divide to form cork cells on outer side and cortex on inner side
Explain secondary growth at root
increase circumference of roots
cambium ring divide inward to form secondary xylem and outwards to form secondary phloem
cork cambium actively divides to form cork cells
Necessity of primary growth
Primary phloem transport product of photosynthesis to other part of plants
Primary xylem provide mechanical support to herbaceous and young plants
Primary xylem transport water and mineral salts from soil to the leaf
Maximum elongation of plant to absorb sunlight for photosynthesis
Necessity of secondary growth
Provide mechanical support to plant through thickening of lignin
Produces more xylem and phloem tissue
Provide stronger and thicker bark to provide protection to the plant
Replace old and damage xylem and phloem tissue
4 Stages of growth curves of annual plants
Decreasing in dry mass ; food stored in cotyledon is used for germination
Increasing dry mass; rate of growth increase rapidly as plant carries out photosynthesis
Constant dry mass; Plant is matured
Decreasing dry mass; aging, lower rate of photosynthesis
2 season of growth curves of biennial plants
First: Photosynthesis takes place, food is stored in tubers
Second: Food stored is used to produce flower and seeds
