3.1 Exploring Plant Diversity Flashcards
importance of plants
-Form the base of almost all food chains
-Provide food, fuel and fibre
-Found within medicines (e.g. Aspirin)
-Release O2
-Cycle nutrients
-Clean air, purify water, absorb carbon and detoxify soil
-Some can clean up pollution that seeps into the environment
what are 3 characteristics that all plants share?
-eukaryotic
-cell walls contain cellulose
-carry out photosynthesis
evolution of plants
Transformed from aquatic, algae-like plants by evolving:
-Formation of an embryo
-Ability to stand upright and grow
-Vascular tissues to transport nutrients, water, and waste
-Strategies to reduce water loss
-Strategies to disperse reproductive structures without water current
Fossil and biochemical evidence indicate;
______________ are the oldest group of plants
__________ the youngest
green algae; flowering plants
oldest evolved plants to newest evolved plants
green algae
mosses & relatives
ferns & relatives
cone-bearing plants
flowering plants
vascular plants - sexual reproduction
-spores
-seeds not enclosed in fruit (gymnosperms)
-seeds enclosed in fruit (angiosperms)
alternation of generations
-most plants have a life cycle that alternates
between diploid and haploid forms
Diploid = 2 sets of chromosomes
Haploid = 1 set of chromosomes
____________________________ produces egg and sperm cells called gametes
Haploid generation (gametophyte)
______________________ produces spores
Diploid generation (sporophyte)
Conifers
-Conifers also go through alternation of generations
-They have two separate cones, male and female, that are the gametophytes
-Zygote produces a seed
-Sporophyte is dominant
spores
-haploid but they can develop into a new organism
-can develop tough coats that enable them to persist in unfavourable conditions
gametes
are haploid so they must fuse with another gamete to form a zygote (that is now diploid)
true or false: Sporophytes are usually the dominant generation (*except for mosses)
true
major groups of plants
5 groups:
Green algae
Mosses
Ferns
Seed plants
Flowering plants
green algae is found in _________ around edges of __________
shallow freshwater; ponds and lakes
green algae have
cell walls and photosynthetic pigments
green algae are modern relatives of ______
plant ancestors
true or false: algae undergo alternation of generations
false
mosses
seedless non-vascular plants
mosses are the first to branch off from ___________
aquatic ancestors
true or false: mosses don’t have seeds, stems, or rigid support structures
true
because mosses are non-vascular, they are ____
short
in mosses, _______ are the dominant generation, called ________
gametophytes; bryophytes
true or false: in mosses, sperm and eggs are produced in the same structure
false… separate structures
in mosses, how do sperm get to eggs?
they’re flagellated and must swim through water to meet eggs
ferns
seedless vascular plants
ferns have vascular tissue, therefore they are _____
taller
what is the dominant generation in ferns?
sporophyte
what is the gametophyte called in ferns?
prothallus
gametophyte in ferns has ________________ structures
sperm and egg producing structures
true or false: in ferns, sperm are flagellated
true
where are spores found in ferns?
on the underside of the sporophyte leaf