1110 seed plants powerpoint notes Flashcards
evolution of seed plants
1
Q
microscope
A
retained within sporophyte
- develops into gametophyte (micro gametophyte or pollen grain)
produces 2 sperms
2
Q
megaspore
A
- retained within sporophyte
- develops into gametophyte ( aka mega gametophyte) or embryo sac produces 1 egg
3
Q
produce seeds
A
reproductive structures consisting of a seed coat, a food supply and an immature sporophyte embryo
4
Q
provide protection
A
seed coat provides greater protection against desiccation than spore walls
5
Q
promote dispersal
A
seed coat often modified to enhance dispersal by wind or animals
6
Q
allow for extended dormancy
A
enhances survival of sporophyte embryo
7
Q
gymnosperms (naked seed)
A
- nonflowering seed plants
- each pollen grain contains 2 sperm
8
Q
seat coat
A
derived from parent sporophyte (2n)
9
Q
food supply
A
derived from megagametophyte
10
Q
embryo
A
is new sporophyte of next generation
11
Q
cycads
A
- slow growing
- xylem consists of tracheids
- tissues highly toxic if ingested
12
Q
ginkgos
A
- native to china
- slow growing trees
- xylem consists of tracheids
- unique fan shaped leaves with dichotomous venation
13
Q
gnetophytes
A
- xylem consists of tracheids and vessel elements
- most are dicecious
- variable body forms
14
Q
conifers
A
- xylem consists of tracheids
- small , needle like leaves ( reduce water loss)
15
Q
ANGIOsperm
A
complex vascular tissue
- xylem composed of both tracheids and vessel elements
