Bio-1-Lecture-2 - Classification of Plants PDF

IMANUEL P. PRUDENTINO What is a plant? Give important characteristics? Plants can be classified into 4 main class: 1.Bryophyta – mosses and liverworts 2.Pteridophyta – ferns 3.Gymnosperm – conifers, pines 4.Angiosperm – flowering plants  MOSSES (PHYLUM BRYOPHYTA),...

IMANUEL P. PRUDENTINO What is a plant? Give important characteristics? Plants can be classified into 4 main class: 1.Bryophyta – mosses and liverworts 2.Pteridophyta – ferns 3.Gymnosperm – conifers, pines 4.Angiosperm – flowering plants  MOSSES (PHYLUM BRYOPHYTA), LIVERWORTS (PHYLUM HEPATOPHYTA), AND HORNWORTS (PHYLUM ANTHOCEROPHYTA). SMALL AND LOW- GROWING FOR TWO REASONS. ⚬ LACK OF VASCULAR TISSUE ⚬ ALTERNATION OF GENERATIONS  The first group of land plants are the mosses as well as the liverworts and hornworts. Together, they are called the bryophytes. They are land plants, but do not have seeds or flowers. The Phylum Bryophyta, are the most diverse group with more than 10,000 plant species. Among all plant phyla, the members of the Phylum Bryophyta are considered the simplest.  Bryophytes lack vascular tissue and wood that can render them structural support. They also lack true leaves, stems, and roots that can help them transport water and nutrients.  MOSSES/ LUMOT MOSS, (PHYLUM BRYOPHYTA), ANY OF AT LEAST 12,000 SPECIES OF SMALL NONVASCULAR SPORE-BEARING LAND PLANTS. MOSSES ARE DISTRIBUTED throughout the world except in salt water and are commonly found in moist shady locations. They are best known for those species that carpet woodland and forest floors. QUESTION: BASED ON OUR DAILY LIVES, WE CAN NOTICE THAT MOSS / LUMOT TENDS TO GROW ON CONCRETE. WHY? MOSSES SETA – THIN STALK CAPSULE – BULB CONTAINING THE SPORANGIUM SPORANGIUM – PRODUCES THE SPORES  Hair-like projections that grows on the epidermal cells of Bryophytes It links the organism's growing body to a substratum. Responsible for uptake of nutrients and minerals.  A sporangium (plural: sporangia) is the capsule structure belonging to mosses, in which the reproductive spores are produced and stored.  The matured sporophyte will have sporangium which in turn will produce sporocytes. Each sporocyte will undergo meiosis and thus produce 4 haploid spores. These are single-celled structures and are haploid, and it begins to germinate. These spores are then released and will eventually become either a male or a female gametophyte, continuing the life cycle.  2 chromosomes 1 chromosomes Abbreviated by “2N” Abbreviated by “N”  Spores that are created by the sporangium is called ASEXUAL REPRODUCTION which means that they do not need 2 sexual gametes to reproduce (MITOSIS) The spores can divide and copy itself to create an another organism (MEIOSIS)  Spores are created through meiosis which is a process that produces spores (4 haploid cells) with unique genetic information.  The sporophyte refers to the diploid generation of the moss. It remains attached to the gametophyte (the haploid mother) BRIEF RECAP There are two stages that mosses go through in their life cycle. FOR YOU TO BETTER UNDERSTAND THE CONCEPT...... The process will repeat again.. FROM THE PERSPECTIVE OF THIS CONCEPT FIGURE, LET US COMPARE THEM! Why does the sporophyte is attached to the gametophyte? Question. Why does moss tend to have an abundant presence in forest floor?  LIVERWORTS LIVERWORTS BELONG TO PHYLUM HEPATOPHYTA Often grow in wet rocks or in greenhouses Can be thallose or leafy DID YOU KNOW? THE THALLUS (BODY) OF THALLOSE LIVERWORTS RESEMBLES A LOBED LIVER—HENCE THE COMMON NAME LIVERWORT (“LIVER PLANT”). MOST LIVERWORTS CAN REPRODUCE ASEXUALLY BY MEANS OF GEMMAE, WHICH ARE DISKS OF TISSUES PRODUCED BY THE GAMETOPHYTIC GENERATION. THE GEMMAE ARE HELD IN SPECIAL ORGANS KNOWN AS GEMMA CUPS AND ARE DISPERSED BY RAINFALL.  What is Gemmae? Liverworts can also reproduce asexually by means of special structures called gemmae cups. These little cups can be easily seen on the surface of the plant. Each gemma cup contains a number of tiny plantlets called gemmae, and a single drop of water will disperse them. These little vegetative “clones” will then grow into a new gametophyte. LIVERWORTS ASEXUAL REPRODUCTION These structures function in vegetative (asexual) reproduction; when a droplet of water falls into the gemma cup, the gemmae themselves may be dispersed some distance away, growing into a haploid genetic clone of the parent. LIVERWORTS SEXUAL REPRODUCTION Archegoniophores -Female plants make umbrella-like reproductive structures that produce eggs. Antheridiophores - male (sperm bearing) Male plants make reproductive structures topped by a flattened, lobed disc that produce sperm. female (egg producing)  In the presence of water, swimming sperm from the male plant can be splashed up on a nearby female structure. The fertilized ovum develops and remains attached under the lobes of the female structure. Male and female spores are produced on hair-like structures that move to facilitate spore release and dispersal.  LIVERWORTS Liverwort, (division Marchantiophyta), any of more than 9,000 species of small nonvascular spore-producing plants. Liverworts are distributed worldwide, though most commonly in the tropics. The tropics are regions of Earth that lie roughly in the middle of the globe. The tropics between the latitude lines of the Tropic of Cancer and the Tropic of Capricorn. The tropics include the Equator and parts of North America, South America, Africa, Asia, and Australia. Question? Why in the tropics? What is special about the tropical region? In tropical region, humidity rate is high which gives rise to the environment preferred by Bryophytes. This region has an abundant access to water, by which temperature can go down when condensation happened including the soil temporarily. HORNWORTS HORNWORTS BELONG TO PHYLUM ANTHOCEROPHYTA Found in tropical forests and along streams Flat, lobed body with little green “horns” THEY ARE HORN-LIKE STRUCTURES THAT ARE WIDELY FOUND IN HUMID, DAMP AND THERE ARE APPROXIMATELY 300 SPECIES OF KNOWN HORNWORTS SHADY AREAS.  HORNWORTS The main plant body is thallus-like and lacks true roots, stem and leaves. Its flattened body is haploid and produces gametes. Thus, it is known as a Thallus gametophyte. HORNWORTS  Question? What is the function of stomata? Spores produced inside hollow column that splits open at Hornworts produce multicellular maturity structures called sporophytes. These structures get attached to the photosynthetic gametophyte and derive nutrition from them. A fertilized egg in a female sex organ develops into an elongate sporangium, which splits lengthwise as it grows, releasing the spores that have developed within it. Sexual Reproduction – involves male and female gametes Asexual Reproduction- involves haploid cells (spores) that forms the gametophyte when the spore develops  Hornworts serve as good aquarium plants. They carry photosynthesis and provide oxygen to the fishes. They also act as a site for breeding. The fish can hide their fry on the tiny leaves of hornworts. Moreover, hornworts also absorb waste components like nitrates, phosphates and Ceratophyllum demersum ammonia in an aquarium.  Ammonia is the most toxic nitrogenous waste product in an aquarium which can cause stress and possible death to aquatic life if not addressed. formed from the metabolism of protein and is the major waste product of fish. The majority of ammonia from fish is excreted through the gills, with relatively little being lost through urine and feces  ECOLOGICAL IMPORTANCE OF BRYOPHYTES? They prevent soil erosion by reducing the impact of the falling rain  ECOLOGICAL IMPORTANCE OF BRYOPHYTES? They usually grow densely and hence act as soil binders. Mosses grow in dense strands forming mat or carpet- like structure Bearing the impact of falling rain drops, Moss holds much of the falling water and reducing the amount of run-off water. They are capable of absorbing large amounts of water, with water storage capacities ranging from 100 to 5000% of their dry weight, depending on the moss species  ECOLOGICAL IMPORTANCE OF BRYOPHYTES? The absorptive properties of mosses allow extensive colonies to provide water filtration slowing down the rush of stormwater and giving it a chance to reach the soil.  ECOLOGICAL IMPORTANCE OF BRYOPHYTES? In a study conducted by Gall et. al., 2024, it was demonstrated In this study that mosses have a large impact on surface runoff, amount of percolated water, and soil loss. Mosses significantly reduced surface runoff by 91% and soil loss by almost 100% compared with bare soil, while the amount of percolated water was increased by 85%. https://doi.org/10.1007/s11756-024-01666-w  MOSS DECOMPOSES ROCKS They decompose the rock making it suitable for the growth of higher plants. The acid secreted by lichens, death and decay of mosses helps in soil formation Lichens: They secrete acids that slowly break down rocks. Over time, this process turns rocks into smaller particles that can become part of soil. Mosses: When mosses die and decay, their remains mix with the rock particles, adding organic material to the soil.  Tracheophytes Vascular tissues (xylem and phloem) Pteridophyta, Gymnosperms, Angiosperms Common name: Narra Scientific name: Pterocarpus indicus Question: What do you think is the reason why vascular plants are taller than non-vascular plants? Question: What are the difference between Xylem and Phloem?  “gymnos” naked, and “sperma” seeds Reproduce by means of an exposed seeds or ovules 83 genera, 12 families and 1,080 living species. Seeds are not borne on flower or in fruit as in angiosperm A group of plants which produce seeds that are not contained an ovary or fruit. The seeds are open to air and are directly pollinated by pollination.  Gymnosperms are known as naked seeds because their seeds are not enclosed within an ovary like flowering plants. Instead, gymnosperm seeds are exposed and unprotected by a fruit or seed coat.  “cone” as their reproductive structure Possesses needle like leaves Conifers and pines  Heterosporous o male microspore and the female megaspore megaspore: the larger spore of a heterosporous plant, typically producing a female gametophyte microspore: a small spore, as contrasted to the larger megaspore, which develops into male gametophytes through mitosis  female cones are bigger than male cones and are located higher up in the tree. A male cone contains microsporophyll where male gametophytes ( pollen ) are produced and are later carried by wind to female gametophytes. They include 4 Phyla: Coniferophyta (conifers) Cycadophyta (cycad) Ginkgophyta (ginkos) Gnetophyta/Gnetopsida (ephedra)  Phylum Coniferophyta ‘cone-bearer’, Include some of the largest, tallest and oldest trees on the planet 50 genera and 550 species Some conifers are deciduous Have vascular tissues Cones house their reproductive structure  Phylum Coniferophyta Needle-like leaves o Conifers have needle-like leaves to hold more moisture and reduce wind resistance. o The long, rolled needles can hold water throughout the year, even during drought or cold weather.  Phylum Cycadophyta 2nd largest group of gymnosperms, 11 genera and 140 species Palm like or fernlike symbiotic relationship with bacteria seeds can be dangerous to humans or animals if they are ingested  Most parts of the plants are toxic The seeds contain a higher concentration of cycasin. Clinical signs include: vomiting Diarrhea Lethargy Depression liver failure, Coagulopathy Weakness Ataxia Seizure coma may also be seen And death  Cycads are the only gymnosperms and among the few plant lineages that evolved a specialized root organ to host a symbiotic relationship with endophytic bacteria that fix nitrogen. Their lateral roots can develop into coralloid roots, a dichotomous and coral-like small cluster of roots, typically growing above ground, that acquire symbiotic bacteria Cyanobacteria and; Caulobacter spp. https://doi.org/10.1093%2Fgbe%2Fevy266  Symbiosis is a relationship or interaction between two or more species that share a common habitat. Mutualism: Mutualism occurs when both creatures involved benefit from each other. Commensalism: Only one organism benefits from commensalism, whereas the other is neither benefited nor injured. Parasitism: Parasitic relationships benefit one creature while harming the other.  Nitrogen is a major component of: proteins hormones chlorophyll vitamins and; enzymes genetic material (nucleic acids). Nitrogen metabolism is a major factor in stem and leaf growth (vegetative growth). Typical deficiency symptoms: leaf yellowing, stunted growth. Nitrogen metabolism is a major factor in stem and leaf growth (vegetative growth). Typical deficiency symptoms: leaf yellowing, stunted growth.  Ginkgophyta – Ginkgo biloba 300 million – 1000 yrs connecting cells with tiny perforations called valves Older trees sometimes also have odd downward growths, called Chichi Grow from a damaged stem or by putting out new shoots from the ground  Gnetophyta 70 species divided into three genera: Gnetum are mostly vines or shrubs (30 species) Ephedra “Mormon tea”. 30 species Welwitschia contains only one species (Welwitschia mirabilis). They have the largest leaves in plant kingdom and survives in extreme drought.  “angeion”: vessel/container and “sperma” seed. The name Angiosperm translates to “vessel seed” which refers to ovules being enclosed in the carpel. Largest group of plants. 270,000 species. 80% living plants. Flowers, fruits and seeds: ovules enclosed in an ovary. Pollination is the process of reproduction Anthophyta (flowering plants) ⚬ Monocot ⚬ Dicot  Flower – reproductive organs Diversity – trees, herbs, shrubs,vines, epiphytes, aquatic, terrestrial Orchidaceae (ORCHIDS) Asteraceae (DAISY) Fabaceae (LEGUMES) STAMEN- The pollen producing part of a flower, usually with a slender filament supporting the anther. Anther: The part of the stamen where pollen is produced. PISTIL- The ovule producing part of a flower. The ovary often supports a long style, topped by a stigma.  Female reproductive part The carpel is one of the organs that make up what is arguably the defining feature of the angiosperms, the flower. Have three main parts: Ovary, style, stigma  The stigma is part of the female reproductive system of a flower. It is found in the center of a flower and helps to collect pollen. Its main function is to attract the pollen grains from the air with its sticky tip for reproduction to take place. SUMMARY  SUMMARY When the pollen grain germinates on the stigma, it creates a burrow called POLLEN TUBE as it travels towards the ovary  WHERE DOES THE POLLEN TUBE CAME FROM? Pollen consists of one or more vegetative cells and a reproductive cell. In angiosperms and certain gymnosperms, the vegetative cell forms the pollen tube that grows to meet the unfertilized ovules, and the reproductive cell is the source of the sperm. Pollen from the anther of one plant is transferred to the stigma of a different plant which results in the production of fertile seeds. Question: What do you think will happen if a bee pollinated a different type of flower?  Monocotyledons 60,000 species. Orchidaceae: 20,000 species. Leaves have parallel venation Have scattered vascular bundles Fibrous root system, whorled arrangement of floral parts.  Dicotyledons 2 embryonic leaves or cotyledons 200,000 species. Tap root system with few lateral branches Vascular bundle are arranged in ring. Flowers are in multiple of four or five. Leaves are net-veined  Plant veins play a vital role, providing an efficient transport route to transfer sugar, water, and nutrients throughout the plant. Made up of Xylem and Phloem  Asteraceae or Compositae 32,000 species Aster family Aster, daisy, composite, sunflower  Fabaceae/Leguminosae 20,000 species Pea family Beans, peanut, sensitive plant, acacia  Rubiaceae 13,500 species Coffee family Coffee, santan, gardenia  Euphorbiceae 5,000 species Spurge family Euphorbias, cassava, castor plant, poinsettia  Malvaceae 4,300 species Mallow family Okra, cotton, cacao, durian  Orchidaceae 28,000 species Orchid family Dendrobium, cattleya, vanilla  Poaceae or Graminae 12,000 species Grass family Bamboo, corn, rice  Cyperaceae 5,500 species Sedge family Grass-like Water chestnut, papyrus sedge, nutgrass  Araceae 3,750 species Arum family Peace lily, taro, Monstera  Phylum Pteridophyta Lower vascular plants Seedless, spore- producing Leave – fronds Stems – Rhizomes Have vascular tissues Aquatic or terrestrial  Unlike other Vascular plants, Ferns do not produce flowers, seeds, fruit, or wood. possess true roots, stems, and complex leaves and that reproduce by spores. They occupy shady forest, DID YOU KNOW? Ferns can be the full sun of deserts, high found in almost any habitat. mountains, and lakes. Moist, shady forest and lakesides are considered “typical” fern Woodsia Cheilanthes Azolla Ceratopteris Lygodium  All ferns are perennial and herbaceous; none is woody But some achieve the size of small trees They do not have secondary Xylem and vascular cambium Cyathea  Secondary growth is the outward growth of the plant, making it thicker and wider. Vascular cambium – the type of cell associated with this growth Vascular cambium is responsible for the secondary growth in plant stem Gives rise to secondary phloem and xylem Sori (singular: sorus) are groups of sporangia (singular: sporangium), which contain spores. Sori are usually found on the underside of the blade. Young sori are commonly covered by flaps of protective tissue called indusia (singular: indusium).  Membranous protective structure (indusium) The indusium is round, shaped like a tiny umbrella and attached to the leaf from the middle. Protection of the sporangial cluster from exposure, drying, and other hazards