Lab 4 Flashcards
anatomy of a leaf
waxy cuticle
epidermis
mesophyll (vascular bundle, xylem, phloem)
stoma (guard cells and pores)
waxy cuticle function
covers the surface of the leaves, minimizing water loss
stoma function
present in leaves and in stems, allows gas exchange
vascular tissue function
transport materials throughout the plant
4 major plant groups
bryophytes
ferns
gymnosperms
angiosperms
plant challenges to living on land, and solutions
water loss, waxy cuticle
gas exchange, stomata
structural support, lignin in vascular tissue
reproduction, fertilization, pollinators
which plant group needs water for reproduction
moss
ferns
sperms need to swim
which plant group has seeds
gymnosperms (seeds not protected) and angiosperms(seeds protected)
what is a seed (3 parts) and its advantages
embryo, seed coat, food supply.
Seed coat protects embryo from desiccation & from getting crushed.
Seeds contain an abundant food supply for the embryo: embryo can develop
Embryonic development is very advanced before the seed germinates & the plant is exposed to the environment. Compare with moss & ferns: embryos never protected
Mechanisms for seed dispersal ensure that the embryo will grow away from parent plant to reduce competition with the parent
What is a fruit?
ovaries of flowers
gravitropism in plants
growth by a plant in response to gravity pulling on it
toward gravity: positive
away from it: negative
phototropism
the orientation of a plant or other organism in response to light, either toward the source of light ( positive phototropism ) or away from it ( negative phototropism ).
Ecological Importance of Plants
Base of terrestrial food chain Produce oxygen (& CO2) Carbon store (fix CO2) Moderate climate (shade & fix CO2, a greenhouse gas) Provide cover/habitat for wildlife Stabilize soil (roots)
Economic importance
All our major food crops
Paper, wood for homes/furniture
Medicines
