RAB Quarter 2 Notes PDF

DIFFERENT DIVISIONS AND ITS CHARACTERISTICS - November 5, 2024 CHARACTERISTICS OF BRYOPHYTES What are bryophytes? - Bryophytes, such as mosses, are spore-bearing plants that have stems and leaves, yet do not have true roots. Instead, they have rhizoids, or small hair-li...

DIFFERENT DIVISIONS AND ITS CHARACTERISTICS - November 5, 2024 CHARACTERISTICS OF BRYOPHYTES What are bryophytes? - Bryophytes, such as mosses, are spore-bearing plants that have stems and leaves, yet do not have true roots. Instead, they have rhizoids, or small hair-like structures, that anchor them in their place of growth. KEY FEATURES OF BRYOPHYTES: - Non-vascular - Bryophytes are non-vascular, meaning that they do not have any xylems or phloems and in place, they have conductive tissues. This means that they do not grow as large as other plants. - Moisture-dependent - They usually grow in places that have a lot of moisture, as not only do they need water for survival, but they also need it for reproduction. This is because the water aids in spore dispersion, which is important in the plant’s reproduction. PARTS OF BRYOPHYTES: - Seta - The seta is a stalk-like structure that holds up the capsule, helping in spore dispersion. - Capsule - The capsule, held up by the seta, is a sporophyte that produces, holds, and releases spores. - Leaves - The leaves of bryophytes are considered untrue or incomplete. - Rhizoids - The rhizoids function as “roots” for bryophytes, but unlike real roots, they cannot absorb water, and their sole purpose is to simply hold the plant down.  - 1 CHARACTERISTICS OF PTEROPHYTES What are pterophytes? - Pterophytes are spore-bearing plants with a complete vascular system, that refers to their leaves as fronds. This species includes ferns, horsetails, which are named as such due to their stem’s brushy appearance, and whisk ferns. KEY FEATURES OF PTEROPHYTES: - Vascular - Pterophytes are vascular plants, which means they have xylems and phloems. In turn, they can grow quite larger in relation to other divisions of plants, namely bryophytes. PARTS OF PTEROPHYTES: - Sorus - Also known as sori, it is a sporophyte that produces and holds the spores to be released. - Sporangium - Part of the sporophyte, the sporangium is in charge of releasing the spores produced and held by the sori. - Frond - The fronds of the pterophytes act as the “leaves” of the plant and are where the sori are usually found. - Fiddlehead - Considered a young sporophyte, it sprouts in order to provide energy and eventually turns into a frond. - Prothallium - A male part of pterophytes in charge of making male gametes or sperm cells. - Prothalus - The female counterpart to the prothallium. It produces the female gametes or egg cells. 1 https://www.geeksforgeeks.org/bryophyta/  - Rhizoids - Although also called rhizoids, a pterophyte’s rhizoid has the ability to absorb water. - 2 CHARACTERISTICS OF GYMNOSPERM What are gymnosperms? - Gymnosperms are types of plants that produce seeds not enclosed inside an ovary, but through their cones. This includes the phyla of Cycadophyta, which is the second largest group of gymnosperms after conifers; phylum of Ginkgophyta, which only contains one surviving species, Ginkgo biloba (a.k.a. maidenhair); and phylum of Coniferophyta, which is the largest group of gymnosperms, with 600 species of conifers, including pine trees and the sequoia tree. KEY FEATURES OF GYMNOSPERM: - Vascular - Pterophytes are vascular plants, which means they have xylems and phloems. In turn, they can grow quite larger in relation to other divisions of plants, namely bryophytes. - Conifers - In place of releasing spores to reproduce, gymnosperms reproduce by making cones. PARTS OF GYMNOSPERMS: - Male cones - Part of the gametophyte and smaller than female cones, they disintegrate after releasing pollen. 2 https://biologynotesonline.com/pteridophyta/  - Female cones - Part of the gametophyte and larger than male cones, this is where the zygote grows. - Megasporangium - The megasporangium is in charge of producing female gametes or egg cells. - Microsporangium - The microsporangium is in charge of producing male gametes or sperm cells. - Sporophyte - The sporophyte of gymnosperms is the tree itself. - 3 CHARACTERISTICS OF ANGIOSPERM What are angiosperms? - Angiosperms are types of plants that produce seeds enclosed inside an ovary and have the capability of producing flowers, unlike gymnosperms. This is the largest and the most diverse group of not only the sub-kingdom Embryophyta but the whole Plantae kingdom, containing more than 300,000 species of flowering plants. KEY FEATURES OF ANGIOSPERMS: - Vascular - Angiosperms are vascular plants, which means they have xylems and phloems. In turn, they can grow quite larger in relation to other divisions of plants, namely bryophytes. - Seeds - In place of releasing spores to reproduce, angiosperms reproduce by making seeds. 3 https://quizlet.com/435358891/general-bio-ii-gymnosperm-life-cycle-aka-pines-diagram/  PARTS OF ANGIOSPERMS: - Gynoecium - The gynoecium is the female reproductive part and is also the innermost whorl of a flower. It consists of the ovary, ovules, stigma, and style. - Androecium - The androecium is the male reproductive part and consists of the pollen grain, microsporangia, anther, and filament. - 4 Other important terms: Sporophytes - Reproduction is by producing spores. Results in the plant being spore-bearing. Gametophytes - Reproduction is by producing gametes (sex cells). Results in the plant being seed-bearing. Antheridium - Male gametophytes in charge of making sperm cells. Archegonium - Female gametophytes in charge of making egg cells. Incomplete Flower - Only has EITHER male OR female reproductive parts. Complete Flower - Has BOTH male AND female reproductive parts. Complete and Perfect Flower - Has ALL four whorls and BOTH male and female reproductive. Vascular - Has vascular tissues, or has a xylem and phloem. This presence causes some plants to grow larger. Non-vascular - Has no vascular tissues, or has no xylem and phloem. This absence causes some plants to grow less. 4 https://nhpbs.org/natureworks/nwep14f.htm