Lecture 2 DA Flashcards
What are streptophytes?
Collective group that are closest relatives to land plants.
What are embryophytes, and what are they a subgroup of?
Group that has a protected embryo. Subgroup of streptophytes.
Why are embryophytes important?
They have a significant evolutionary advantage over aquatic plants.
What are tracheophytes?
Vascular plants with a plumbing system.
What dominates plant life?
Flowering plants, gymnosperms.
What can reproduction in plants be considered?
Dihaplontic.
What is a dihaplontic cycle?
Multicellular haploid phase, and multicellular diploid phase.
What cell organisation do plant gametophytes have?
Multicellular.
How do plants produce gametes?
By mitosis, via gametophytes.
What are sporophytes, and how do they develop?
Gametes produced by gametophytes fertilise and develop into sporophytes.
What do sporophytes do?
Produce spores by meiosis.
What cell organisation do spores have?
Single-celled.
What is a male gametophyte?
Pollen grain.
What happens when a spore germinates?
Develops into a gametophyte, multicellular.
Over time, what happened to the usage of gametophytes and sporophytes in plant lifecycles?
Progressive reduction in gametophyte production, and an increase in sporophytes.
Are moss embryophytes?
Yes
Where is the zygote of moss found?
In the gametophyte.
Is a moss zygote released to form a spore?
No, it develops into a spore within the gametophyte.
When are moss spores released, and what structure do they have to aid them?
Released when dry, and have a waxy coating to prevent maceration.
What happens when moss spores mature?
Germinate into a gametophyte by meiosis, either male or female.
What is a male moss gametophyte called? What about female?
Male - antheridia
Female - Archegonia
Are mosses mono or diecious? What does this mean in terms of gametophyte production?
Monoecious, both gametophyte genders can be on the same plant.
What does sperm need to reach the egg?
Water.
Do bryophytes have true roots and leaves?
No, they have false ones.
What are bryophyte roots and leaves called?
Leaves - microfils
Roots - rhizoids
Why are bryophyte roots false?
They anchor but do not absorb.
Can bryophytes reproduce asexually?
Yes.
What are gemmae and thalluses?
Involved in asexual reproduction in bryophytes.
Gemmae cups are produced, and water splashes in, ejecting structures that germinate into thalluses.
Are bryophytes vascular?
No vascular tissue.
Do bryophytes have cuticles? Can they survive dehydration?
They have no cuticle, and can survive 80% dessication.
How do bryophytes disperse?
Spores.
Do bryophytes have lignin?
No.
What structure do moss, liverwort and hornwort have?
Moss - leafy
Liverwort - leafy or thallus
Hornwort - thallus
What cell organisation do rhizoids have in modd, liverwort and hornwort?
Moss - multicellular
Liver+hornwort - unicellular
What position are microfils in moss, liverwort and hornwort?
Moss - prostrate or upright
Liver+hornwort - prostrate
What are stele cells? What has them?
Vascular like cells, but not true vascular cells, arranged in rows. Leafy liverwort can have them.
What is the seta/stalk of sporophytes in moss, liverwort and hornwort like?
Moss - wiry
Liver+hornwort - soft
What is the growth rate of sporophyte seta/stalk in moss, liverwort and hornwort like?
Moss - gradual
Liver+hornwort - rapid
