Bryophytes and Seedless Vascular Plants Comparison, Pollination and Seed Dispersal Mechanisms, Angiosperms: Flowers, Fruits, and Their Importance, Overview of Gymnosperms and Seed Plant Features, Water and Sugar Transport in Plants, Seedless Vascular…

Dominant generation in bryophytes

The dominant generation in bryophytes is the gametophyte.

Dominant generation in seedless vascular plants

In seedless vascular plants, it is the sporophyte.

Megaspore

A spore that develops into a female gametophyte.

Microspore

A spore that develops into a male gametophyte.

Homosporous

Producing one type of spore.

Heterosporous

Producing two types of spores (microspores and megaspores).

Phylum Lycophyta

Includes club mosses, spike mosses, and quillworts.

Phylum Monilophyta

Includes ferns, horsetails, and whisk ferns.

Common features of seed plants

Seeds with a protective coat, embryo with a nutrient supply, ovules and pollen grains, vascular tissues, heterospory (production of both microspores and megaspores).

Gymnosperms

Gymnosperms are 'naked seed' plants that appeared around 305 million years ago and were dominant during the Mesozoic era.

Angiosperms

Angiosperms are flowering plants classified under Phylum Anthophyta, characterized by flowers and fruits that aid in reproduction and seed dispersal.

Sepals

Protect the developing reproductive structures.

Petals

Attract pollinators.

Stamens

Male reproductive organ consisting of an anther (produces pollen) and filament (supports the anther).

Carpel (Pistil)

Female reproductive organ consisting of stigma (catches pollen), style (connects to ovary), and ovary (contains ovules).

Water pollination (Hydrophily)

Rare, occurring in aquatic plants.

Wind pollination

Common in conifers and grasses.

Animal pollination

Involves pollinators like bees, butterflies, and birds.

Endozoochory

Seeds dispersed through animal ingestion and defecation.

Epizoochory

Seeds attach to animal fur or feathers.

Ballistic dispersal

Seeds are forcefully ejected from the fruit.

Wind dispersal

Seeds are carried by air currents.

Water dispersal

Seeds float and travel via water.

Roots

Anchor the plant and absorb water and nutrients.

Stems

Support the plant and transport nutrients.

Leaves

Conduct photosynthesis.

Xylem

Transports water and minerals from roots to shoots.

Phloem

Transports sugars throughout the plant.

Meristems

Regions of actively dividing cells for plant growth.

Stomata

Pores for gas exchange, controlled by guard cells.

Transpiration

The evaporation of water from plant surfaces, primarily through stomata, driving the movement of water in xylem.

Translocation

The transport of sugars from source to sink via phloem.

Coevolution

Mutual influence between angiosperms and animals.

Animal Herbivory

Plant defenses evolve due to animal feeding.

Pollen Tube Formation

Pollen grain elongates to form a tube.

Sperm Cell Transport

Generative cell divides to create two sperm cells.

Double Fertilization

Two fertilization events in angiosperms; zygote and endosperm.

Gymnosperms

Plants with single fertilization event forming zygote.

Water Pollination

Rare pollination method using water for transport.

Wind Pollination

Common method; relies on air currents for pollen.

Characteristics of Wind Pollination

No bright colors; pollen is small and abundant.

Animal Pollination

80% of flowering plants depend on animal pollinators.

Pollinators

Animals like bees, birds, and bats that aid pollination.

Characteristics of Animal Pollination

Bright petals and nectar to attract pollinators.

Seed Dispersal

Movement of seeds away from parent plants.

Gravity Dispersal

Seeds fall beneath parent plant due to gravity.

Wind Dispersal

Seeds carried away by wind; often lightweight.

Water Dispersal

Seeds travel via rain or submerged in water.

Ballistic Dispersal

Seeds ejected forcefully from fruit by pressure.

Endozoochory

Seed dispersal through animal ingestion and defecation.

Synzoochory

Dispersal by seed-caching animals; often predation.

Epizoochory

Accidental seed dispersal on animal exteriors.

Pollen Grain Germination

Pollen grain grows on stigma to initiate fertilization.

Diploid Zygote

Result of fertilization; develops into an embryo.

Triploid Endosperm

Nutrient supply formed during double fertilization.

Mutualism

Interaction benefiting both plants and pollinators.

Plant Adaptations

Traits evolved for effective pollination and dispersal.

Angiosperms

Angiosperms are flowering plants classified under the phylum Anthophyta. They are the dominant plant group on Earth, with over 250,000 species.

Phylum Anthophyta

All angiosperms are classified in a single group: Phylum Anthophyta.

Key adaptations of angiosperms

Key adaptations include flowers and fruits to benefit wind dispersal and reproduction.

Parasitic angiosperms

While most are free-living and photosynthetic - some are parasitic.

Flower

A flower is the reproductive structure of angiosperms specialized for sexual reproduction.

Pollination

The flower facilitates pollination, often with the help of insects, animals, or wind.

Sepals

The outermost whorl, collectively the calyx, protects the developing reproductive structures.

Petals

The next whorl inside the sepals, collectively called the corolla, often colorful to attract pollinators.

Stamens

The male reproductive organ consisting of an anther (produces pollen) and filament (supports the anther).

Carpels (Pistil)

The female reproductive organ consisting of the sticky stigma, the style, and the ovary.

Receptacle

The swollen end of the peduncle or pedicel, where the other flower parts attach.

Complete flower

A complete flower contains all four parts of a flower: sepals, petals, stamens, and carpals.

Incomplete flower

An incomplete flower lacks one or more of these structures.

Fruits

Fruits develop from the ovary after fertilization and contain seeds. They help protect and disperse seeds.

Cotyledons

Cotyledons are seed leaves found within the embryo of angiosperm seeds. They provide nutrients to the growing plant.

Monocots

Monocots are roughly 25% of angiosperms, about 70,000 species.

Eudicots

Eudicots are more than two thirds of angiosperm species (170,000 species).

Basal angiosperms

Ancient angiosperms, with three small lineages contributing to them, including Amborella trichopoda, water lilies, and star anise.

Magnoliids

Magnoliids consist of about 8,000 species, including both woody and herbaceous plants.

Orchids

One of the largest families of flowering plants, characterized by their one highly modified petal or lip.

Palm Trees

Generally restricted to tropical and subtropical climates, evergreen with large, compound leaves.

Grasses

About 12,000 species and is the 5th largest plant family.

Ecosystem Importance

Bamboo and water are important economically and ecologically, found in almost every ecosystem.

Adaptations to Prevent Predation

Plants can have various adaptations such as drought or fire resistance or produce chemicals.

Examples of Grasses

Includes bamboo, maize, wheat, rice, and barley.

Eudicots

A major group of flowering plants that includes various examples.

Cacti

Most live in dry environments, some extremely dry, and have thick fleshy parts for water storage.

Cacti Characteristics

Many lack true leaves and instead have spines, which are modified leaves for protection.

Cacti Species Count

There are around 1,700 species of cacti.

CAM Photosynthesis

Cacti perform CAM photosynthesis.

Rafflesia

Genus includes the largest flower in the world and consists of 28 species of parasitic plants.

Rafflesia Characteristics

All species are native to Asia, lack stems, leaves, and roots, and smell like a rotting carcass to attract flies.

Rafflesia Pollination

Recent studies suggest that elephants are pollinators of Rafflesia.

Pitcher Plants

Carnivorous plants that evolved in nutrient-poor habitats.

Pitcher Plant Traps

Have modified leaves into pitfall traps with slippery or hairy walls to drown prey.

Photosynthesis Types in Pitcher Plants

Most exhibit C3 photosynthesis, but a few exhibit C4 photosynthesis.

Pollen Grain Cells

Male gametophytes that begin as microsporangia and then form into microgametophytes.

Double Fertilization

Occurs when the pollen tube discharges two sperm into the female gametophyte within an ovule.

Endosperm

Special nourishment and food source within a seed; the integuments become the seed coats.

Cotyledons

The embryo within a seed consists of a root and two seed leaves called cotyledons.

Simple Fruit

A type of fruit that develops from a single ovary.

Pepo

A simple fruit with soft tissue covered by a hard, thick rind, e.g., pumpkins.

Hesperidium

A simple fruit covered in a leathery rind with carpal partitions, e.g., oranges.