study guide 9

Seed Plants Adaptations to Terrestrial Life

• Reduced gametophytes

• heterospory

• ovules

• pollen

• seeds

Heterosporous vs. Homosporous Plants

• Heterosporous Plants:

  • Produce two types of spores:

    • Microspores: Develop into male gametophytes.

    • Megaspores: Develop into female gametophytes.

• Homosporous:

• Produce one type of spore that develops into a bisexual gametophyte that makes both sperm and eggs.

  Ovule, contains, surrounded by?

• contain megasporangium and megaspores, transform into seeds after fertilization. megaspores turn into megasporangium, which in turn makes eggs

• Integument: from the sporophyte surround and protects the megasporagium

  Pollen

• contains gametophyte which makes sperm. surrounded by tough sporpollenim

  Seeds

• made up of an embryo and food supply, packed in a protective coat made of integument

• advantage on terresrial: can stay dormant for several years until conditions are favorable for germination

Key Features of Gymnosperms

Groups

cycads (cycadophyta)

Conifers (coniferophyta)

Ginko ( ginkgophyta)

Gnetophyta

Traits

1. have naked seeds

2. dominant sporophyte

3. mostly wind pollinated

Life Cycle of a Pine

• describe the steps

Diversity of Gymnosperms

• Main groups include:

  • Cycadophyta (cycads): have flagellated sperm, sago palm

  • Ginkgophyta (ginkgo)

  • Gnetophyta (gnetophytes)

  • Coniferophyta (conifers): often have woody cones and needle-like leaves

Distinguishing Features of Angiosperms

• 1. flowers

• seeds contained in fruits

• many rely on animals for pollination and seed dispersal

Parts of a Flower and Their Functions

label and explain the purpose of each parts

• Anther: Produces pollen (male gametophytes).

• Stigma: Receives pollen during pollination.

• Style: Connects the stigma to the ovary.

• Ovule: Contains the female gametophyte; develops into a seed post-fertilization.

• Sepal: Protects the developing flower bud.

• Petal: Attracts pollinators.

Fruits and Their Purpose for Angiosperms

• Fruits: thickened ovary wall that surrounds seeds ( mature ovules)

• Purpose: protect seed and help in dispersal and source of food for many species and animals

  Angiosperm Life Cycle Steps

• Describe the steps in the angiosperm life cycle below

Cross-Pollination in Angiosperms

• Mechanisms to ensure cross-pollination include:

  • Diverse flower structures, attract various pollinators.

  • Temporal separation of male and female flower parts.

  Double fertilization: one sperm nucleus fertilized egg ( produces 2n embryo) another sperm nucleus fertilized polar nuclei

• Monocot characteristics:

• 1. one cotyledon

• veins usually parrallel

• vascular tissue scattered

Eudicot characeritics

1. two cotyledons

2. veins usually netlike

3. pollen grain with three openings

Significance of Gymnosperms and Angiosperms in Human Society

• Gymnosperms: Lumber, paper, and medicines are derived from conifers.

• Angiosperms: Major source of food, textiles, and other economically important products, significantly influencing agriculture and horticulture.