Lecture 15 Gymnosperms and Angiosperms

When did Earth Dry and Warm?How old are oldest gymnosperms?

Devonian Period

251-200 mya

Types of gymnosperms?

coniferophyta, gingkophyta, cycadophyta, gnetophyta

Synapomorphies of Cycads? When did they arise?

Simple aerial trunk lacking lateral branching, dioecous

Arose in 320 mya

Cycad flagella details?

They are biflagellate and asymmetrical roots

Gingkophyta synapomorphies? Arose?

Possess bi-lobed leaves and dichotomous leaf venation, dioceous, flagellated sperm

280 mya

Coniferophyta synapomorphies?Arose? 

Possess nonmotile sperm cells and possess highly lignified leaves

290 mya

Name the Genera in pinaceae, cupressaceae, and auricariaceae

Pinus, Picea, Tsuga

Thuja, Juniperus

Auricaria

What are 4 flower whorls

calyx(sepals), corolla(petals), androecium(stamen), gynoecium(carpels)

Synapomorphies of gnetophyta? Know genera?

Striate pollen, have vessel elements (xylem) with porose perforation plates

Welwitschia, gnetum, ephedra

Anthophyta synapomorphies

Possess flowers and fruits

Ovules with double integument

Double fertilization with 2N zygote and 3N endosperm

Sieve tube members (phloem)

Reduced male and female gametophytes

Complete/incomplete flower? Perfect/imperfect flower? Superior/inferior ovaries?

Complete- all 4 whorls

Perfect- both sexes

Ovary superior- ovary above attachment point of everything else.

Plesiomorphic vs Apomorphic

Plesio: parts spirally arranged, many carpels, unfused

Apomorphic: parts in whorl, fusion of flower parts, complex heads

Liliopsida synapomorphies

Embryos with a single cotyledon

Parallel leaf venation

Atactostele

Fibrous root system that lacks tap roots

Pollen grain with single opening

Flower multiples of 3

Hamamelidopsida synapomorphies

Embryos with two cotyledons

Netlike venation

Steles in rings

Taproots

Pollen grain with 3 openings

Flowers in multiples of 4/5

Parts of seed development for anthopyta

1 egg- female gamete, takes 1 sperm

2 synergids- support egg

2 polar nuclei- receive 2nd sperm, make endosperm

3 antipodal- no function, just die

Mother sporophyte used for nutrition, daughter gametophyte holds 8 cells

endosperm used for rapid growth