plant Diversity

Define plants and distinguish them from multicellular protists (algae)

Plants are eukaryotic, multicellular, photoautotrophic organisms with cellulose cell walls. Although multicellular algae share these traits, algae are aquatic protists, while most plants live on land. Plants are also distinguished by derived traits such as alternation of generations, walled spores, multicellular gametangia, and apical meristems.

Identify the basic resources required by plants and explain why they are necessary

Plants require sunlight, water, carbon dioxide, oxygen, and mineral nutrients. Sunlight, water, and carbon dioxide are needed for photosynthesis, oxygen is needed for cellular respiration, and mineral nutrients are needed for plant growth and cell function.

Compare water and land habitats for plants in terms of: a.) availability of nutrients and light b.) support c.) reproduction and dispersal

In water, plants and algae are supported by water, take up dissolved nutrients directly, and receive light mainly near the surface. Gametes can also be released directly into the water. On land, light is more available, but plants must obtain water and nutrients from the soil and support themselves. Reproduction and dispersal are more difficult without surrounding water, so land plants use adaptations such as spores and pollen for dispersal.

Describe the evolutionary history of plants to include: a.) origin from plant-like protist ancestors b.) expansion into land c.) vascular tissue d.) seeds and pollen e.) flowers and fruit

Plants evolved from green algal ancestors and began colonizing land about 470 million years ago. Adaptations to dry conditions allowed them to survive on land. Vascular tissue later allowed efficient transport of water and nutrients. The evolution of pollen removed the need for water during reproduction, while seeds protected and helped disperse offspring. Flowers improved pollen transfer, and fruits protected seeds and increased their dispersal.

Distinguish between vascular and non-vascular plants

Vascular plants have vascular tissue for efficient transport of water and nutrients and have roots, stems, and leaves that help them access resources and grow larger. Non-vascular plants lack vascular tissue, true roots, stems, and leaves and rely on slow cell-to-cell transport, which limits their size.

Describe the distinguishing characteristics of: a.) mosses b.) ferns c.) gymnosperms d.) angiosperms including e.) monocots and f.) eudicots

Mosses are small non-vascular plants without true roots, stems, or leaves and reproduce using spores. Ferns are seedless vascular plants with true roots and frond-like leaves and also reproduce using spores. Gymnosperms are vascular seed plants with woody stems, pollen, and naked seeds but no flowers or fruits. Angiosperms are flowering vascular plants that produce pollen, seeds, and fruits. Monocots have one cotyledon, fibrous roots, parallel veins, and flower parts in multiples of three, while eudicots have two cotyledons, tap roots, net-like veins, and flower parts in fours or fives.