Plant Diversity Flashcards
1
Q
Important plant characteristics used for broad classification
A
Presence/absence of:
- Vascular tissue
- True leaves and roots
- Seeds
- Fruit
- Dependence on water for fertilisation
2
Q
Major groups of land plants (Divisions)
A
- Bryophytes
- Pteridophytes
- Gymnosperms
- Angiosperms
3
Q
Bryophyte structure
A
Gametophyte:
- No true leaves and roots
- Very small since no vascular tissue
- Produce gametes
Sporophyte:
- Grows on gametophyte
- Has a capsule containing spores
4
Q
Thallus
A
- The name given to the gametophyte plant
- No true roots, stems or leaves
5
Q
Alternation of generations in plants
A
- Haploid Gametophytes (n)
- Produce male and female gametes (n)
- Fuse to form zygote (2n)
- Grows into diploid sporophyte (2n)
- Produces spores (n) by meiosis
- Grows into gametophyte (n)
6
Q
Reproduction in Bryophytes
A
- Gametophytes produce male and female gametes
- Male gametes swim through water to female gametes
- after fertilisation, zygote grows into sporophyte
- sporophyte makes spores which grow into gametophytes
7
Q
Bryophyte examples
A
- Mosses
- Liverworts
- Hornworts
8
Q
The leafy part of a bryophyte
A
Thallus
9
Q
Pteridophyte examples
A
- Ferns
- Horsetails
- Club mosses
10
Q
Fern structure
A
Sporophyte:
- True leaves called fronds
- Fronds often compound leaves
- Vascular tissue
- Often stems form horizontal underground rhizomes
Gametophyte:
- Tiny heart shaped thallus
- Rhizoids
11
Q
Reproduction in pteridophytes
A
- Dominant sporophyte (2n)
- Spores (n) produced in sporangia clusters called sori under fronds
- Spores grow into tiny gametophyte (n) which produce gametes
- Male gametes swim through water to female gametes
- after fertilisation, zygote (2n) grows into sporophyte
12
Q
Gymnosperm examples
A
- Conifers
- Cycads
- Ginkgo
- Welwitschia
13
Q
Another name for the gymnosperms
A
- Naked seeded plants
- Because seed not enclosed by an ovary
14
Q
Gymnosperm structure
A
Sporophyte:
- Dominant, often forming huge trees
- true roots and leaves
- vascular system
- specialised reproductive structures called cones
- seeds in cones
Gametophyte:
- Very reduced as pollen or ovules in cones
- Produce the gametes
15
Q
Reproduction in gymnosperms
A
- Dominant sporophyte (2n)
- produces cones containing pollen (n) and ovules (n)
- pollen carried by wind to female cone
- pollen grows a pollen tube so that male gamete (n) can fertilise the female gamete (n)
- fertilised ovule grows into a seed containing sporophyte embryo (2n)
- seed dispersed (e.g. by wind)
