Angiosperm Evolution Flashcards
What do Angiosperms have to make them inhabit diverse habitats?
Vascular Tissue, Sporophyte dominant, seeds, flowers and fruits.
What is Xylem?
Vascular tissue enabling the conduction of water and minerals.
What is Phloem?
Vascular tissue enabling the conduction of sugar(sucrose)
What is Lignin?
Tissues is tough and gives support they enable the plant to get bigger and taller.
How many cycles do plants have?
Two parts of the life cycle Sporophyte and Gametophyte.
What is a Gametophyte?
Only has one set of chromosomes - haploid(one copy of genes) and is dominant - takes up most of the life cycle
What is a Sporophyte?And advantages?
Has two sets of chromosomes - diploid 2 copies of chromosomes (genes) so any deleterious mutations are masked
What connects the two together in the life cycle?
Meiosis and Fertilisation
What plants produce spores?What do the spores germinate to be?
Land plants up to ferns (pteridophytes) Spores germinate to produce gametophytes that have male and female organs.
Sperm swims from the male to the female and fertilise the eggs there..
What do gymnosperms and angiosperms produce?
Seeds
What do flowers do?
Insect pollination cross pollination from different members of the same species increases genetic variation
What is the role of fruits?
Dispersal of seeds and eaten by animals
What do seed plants have?
They have vascular tissue, divided into two groups, Gymnosperms(naked seeds) Angiosperms(covered seeds flowering plants)
What describes a seed producing plant?
Gametophyte is not free living and is small totally dependent upon the enclosed sporophyte. Female gamete = egg - produced by female gamete = germinated megaspore. Male gamete = sperm -produced by male gametophyte = germinated pollen.
What trends are there between Gametophyte and Sporophyte plants?
Gametophyte dominates (mosses), sporophyte dominates (Ferns and above) All most non seed plants have swimming sperm and require moist conditions. Seed plants have dry (dormant) dispersal of sperm(pollen) and greater diversity of environments. Smaller plants have no vascular tissue compared to higher plants which are therefore larger.
