WhatIsAPlant

What is a Plant? By Lauren Carter and Hailey Unice · You will identify and evaluate the structural adaptations of plants to their land environments. · You will survey and identify the major divisions of plants. **//Review Vocabulary://** · [|Adaptation]**:** any structure, behavior, or internal process that enables an organism to respond to stimuli and better survive in an environment. · **[|Cuticle]:** the waxy waterproof coating on most stems and leaves. · [|Root]**:** a plant organ that absorbs water and minerals, usually from the soil. · [|Stem]**:** a plant organ that provides support for growth. [|· Vascular Tissue]**:** made of tubelike elongated cells through which water and other materials are transported. · **[|Tissue]:** plants that possess vascular tissues · [|Non-vascular Plant:] plants that do not possess vascular tissues ·[|Seeds]: a plant organ that contains an embryo along with a food supply and is covered by a protective coat. A plant is a multi-cellular eukaryote which produce their own food through photosynthesis. Evidence suggests that a billion years ago plants did not exist. Scientists believe that plants evolved from green algae. The first evidence of plants was 440 million years ago. Land plants evolved structural and physiological adaptations that allow them to reproduce and withstand the forces of nature. //__Preventing Water Loss:__// Most fruits, leaves, and stems are covered with a protective waxy layer called the **cuticle**. This creates a barrier that prevents the plants’ water from evaporation. //__Carrying out Photosynthesis:__// Photosynthesis occurs in a plant organ called the **leaf.** Each plant has a unique leaf structure. //__Putting Down Roots:__// Plant organs called **roots** absorb water and minerals from the soil. Soil is the primary source of nutrients for most plants. Roots anchor a place in the ground and some roots are used for storage. //__Transporting Materials:__// //__Reproductive Strategies:__// //__[|Alternation of Generations]:__// The lives of all plants include two stages: the gametophyte generation, and the sporophyte generation. The gametophyte generation results in the development of gametes. The sporophyte generation begins with fertilization. After a gametophyte is fertilized, it becomes a sporophyte and produces gametophytes. · **[|Evolution]:** gradual change in an organism through adaptations over time. · **[|Frond]:** leaves found on pterophytes that vary in length from 1 cm to 500 cm. · **[|Cone]:** scaly structures that support male or female reproductive structures. Since the first land plants came into existence, many changes have occurred. Species have evolved, and evolution and extinction have occurred. Most botanists use plant characteristics to classify plants. There are many divisions of non-seed plants, listed below. These plants produce hard-walled reproductive cells called spores, and may include vascular or nonvascular organisms. //__[|Hepaticophyta]__// Hepaticophytes include small plants called liverworts. These nonvascular plants grow in moist environments, and water and nutrients are moved through the plant by osmosis and diffusion. Studies suggest that they may be the ancestors of all plants. There are two kinds of liverworts: thallose liverworts, which have a broad body that looks like a loved leaf, and leafy liverworts, which have three rows of leaves attached to a stem. //__[|Anthocerophyta]__//Anthocerophytes are small thallose plants with hornlike sporophytes. These plants, also nonvascular, grow in damp shady habitats and also use osmosis and diffusion for transportation. //__[|Bryophyta]__//Bryophytes, or mosses, are nonvascular and use diffusion and osmosis for transportation. Some have elongated cells used for transport. These plants are usually less than 5 cm tall an produce spores in capsules. //__[|Psilophyta]__// Psilophytes, known as whisk ferns, have thin green stems. They are unique vascular plants with no roots or leaves. The stems are covered with small overlapping scales. These plants often live in tropical or subtropical climates. //__[|Lycophyta]__//Lycophytes, or club mosses, are vascular plants that live in moist environments. These plants have stems, roots, and leaves, with leaves containing vascular tissue. Species of today or about 25 cm high, but ancient lycophytes grew up to 30 m. [|Arthrophyta]:Arthrophytes, horsetails, are vascular plants with hollow jointed stems and scalelike leaves. Some of these plants contain large amounts of silica. Most modern horsetails are relatively small, but their ancestors were the size of trees. //__[|Pterophyta]__//Pterophytes, or ferns, were found in ancient forests. Their leaves, **fronds**, can grow up to 500 cm. The size and complexity of these leaves sets ferns apart from other seedless plants. Seed plants produce seeds rather than spores. This is a more effective reproductive system in the dry climates that these plants are found in. All seed plants have vascular tissues. //__[|Cycadophyta]__// Cycads are palmlike trees with scaly trunks. They can be short or grow up to 20 m in height. Cycads produce **cones**, structures that support the reproductive organs. Seeds are produced in female cones, while male cones produce clouds of pollen. //__[|Gnetophyta]__// Genophytes are found in desert environments, with a few in tropical. The three genera are Gnetum, tropical trees and climbing vines, Ephedra, shrubby plants in desert regions, and Welwitschia, with only one species found in Africa. //__[|Coniferophyta]__// Conifers are cone-bearing trees with needle like or scaly leaves. They can be found in a wide range of habitats. They may be tall trees or ground covering shrubs. //__[|Anthophyta]__//Anthophytes, flowering plants, are the largest group of seed plants on earth. Fossils of these plants date to the early Cretaceous Period. Anthopytes produce flowers which develop fruits. These fruits contain one or more seeds.
 * What You’ll Learn:**
 * __SECTION I: ADAPTING TO LIFE ON LAND__**
 * //New Vocabulary://**
 * [|Leaf:]** a plant organ that grows from a stem and is usually where photosynthesis occurs.
 * __Origins of Plants:__**
 * __Adaptations in Plants:__**[[image:Wiki4.JPG width="640" height="480" link="http://en.wikipedia.org/wiki/Alternation_of_generations"]]
 * Stems** are the plant organs that provide support for growth and transport materials through the plant. This includes water and nutrients, and some stems may also be used for storage and photosynthesis. The stems of most plants contain **vascular tissues,** which are tublelike, elongated cells used to transport materials. Plants that posses these are called **vascular plants.** Mosses and other small plants do not posses these, and are classified as **non-vascular plants**. Vascular plants allow plants to live further away from water and can grow larger than nonvascular plants.
 * Seeds** contain an embryo, a food supply and a protective outer covering. Seeds can also assist in dispersal of embryos. Non-seed plants require a film of water to assist in fertilization, which is the main reason that they must live in wetter habitats.
 * __SECTION II: SURVEY OF THE PLANT KINGDOM__**
 * //Review Vocabulary://**
 * //New Vocabulary://**
 * __Phylogeny of Plants__**
 * __Non-Seed Plants__**
 * __Seed Plants__**

Match each number with the correct definition: 1. Root A. a waxy waterproof coating that most stems and leaves of most plants 2. Stem B. a plant organ that grows from a stem and usually is where photosynthesis occurs. 3. Leaf C. a plant organ that absorbs water and minerals usually from the soil 4. Nonvascular D. a plant organ that provides support for growth 5. Vascular Tissue E. are made up of tube like, elongated cells 6. Seed F. plants that possess vascular tissues 7. Plant G. do not have vascular tissues 8. Cuticle H. a plant that organ that contains an embryo, along with a food supply and is covered by a protective coat

Clips: [|Plant Animation] [|The Seed] [|The Life Cycle of a Plant] [|Plant Life Cycle] [|Plant Growing] [|Plant life cycle animation] [|Life Cycle of Plants] [|Life Cycle Picture] [|Photosyntesis][|P] [|hotosynthesis pitcure]