Chapter 8: Introduction to Plants

8-1: The Plant Kingdom Members of the plant kingdom share important characteristics: Eukaryotes Multicellular Autotrophs Perform Photosynthesis to make food. Living on Land Unlike something like multicellular algae, plants do not have water surrounding them to help them: Hold their bodies toward the light Obtain nutrients Reproduce

For a plant to survive on land they must: 1)Have a way to obtain water/materials 2)Retain water 3)Transport materials throughout their body 4)Support their body 5)Reproduce successfully Obtaining Water and Materials Plants must have adaptations that allow them to obtain water and materials from the soil. Retaining Water Because there is more water in plant cells than there is in the air, a plant must have an adaptation to reduce water loss to the air. Cuticle- waxy water-proof layer of a plant

Transporting Materials Just like our bodies, plants need to transport materials to its entire body. In general: -water and minerals are absorbed by the bottom of the plant and need to move up. -Food is made in the top of the plant and need to move down. Most plants have tissues that allow them to perform this task. Tissue- group of cells performing a task Vascular Tissue- internal system of tubelike structures that transport materials in a plant. Plants with vascular tissue are called vascular plants and can grow tall.

Support Land plants do not have water to support them toward the light. The photosynthesizing parts of plants (leaves, stems) need as much exposure to sunlight as possible. In vascular plants, the vascular system strengthens and supports the plant to reach for the light. Reproduction All plants reproduce sexually and it involves fertilization.

Fertilization- when a sperm cell unites with an egg cell. Zygote- the fertilized egg In water, the sperm cell can swim to the egg. But land plants need an adaptation to make it possible for fertilization to occur. Plants have a complex life cycle made up of two different stages or generations. Stage 1: the sporophyte produces spores that eventually grow into new organisms. Stage 2- the spore develops into the gametophyte that produces two different gametes- sperm cells and egg cells.

Plant Life Cycle Sporophyte Meiosis Spores Gametophyte Gametes (egg and sperm) Mitosis Fertilization Grow up Stage 1: Sporophyte (DIPLOID) Stage 2: Gametophyte (HAPLOID) And Grow Up

Nonvascular (Chapter 8) Seedless Vascular (Chapter 8) Seeded Vascular: Non-flowering (Chapter 9) Seeded Vascular: Flowering (Chapter 9) categoryMosses and Relatives Ferns and Relatives GymnospermsAngiosperms typesmosses, liverworts, hornworts ferns, club mosses, horsetails Cycads, ginkgo, gnetopythes, conifers Monocots, dicots Vascular Tissue? NoYes Seeds?No Yes FactsLow-growing, Live near water, no roots Use spores to reproduce, true stem, leaves, roots Seeds used to reproduce, true stem, leaves, roots Seed enclosed in fruit, flowers present Types of Plants

8-2 Nonvascular Plants General Characteristics of Nonvascular Plants: Low-growing Lack vascular tissue- system of tubelike structures that transport water and other materials throughout the plant. Passing of materials is just from cell to cell. Lack roots Obtain water directly from surroundings Sperm cells use the watery environment to swim to the egg cells. Examples of nonvascular plants: mosses, liverworts, hornworts

Mosses There are 10,000 species of mosses. Rootlike structure called rhizoid. The sporophyte grows out of the gametophyte. Sphagnum moss is found in bogs that forms peat. Peat is used as fuel, to heat homes, and cook food. Many mosses are pioneer plants. Moss traps soil that can eventually support other plants. capsule stalk leaflike structure rhizoid Stemlike structure sporophyte gametophyte

Liverworts and Hornworts 8,000 species of liverworts. Found growing as a thick crust on moist rocks or soil along streams. Most liverworts grow flat on the ground. Fewer than 100 species of hornworts. Seldom found on rocks or tree trunks. Live in moist soil, often mixed with grass plants.

8-2 Review 1)What are five general characteristics of nonvascular plants? 2)What are three examples of nonvascular plants? 3)Draw and label the parts of a moss plant. 4)Where do liverworts grow? 5)Where do hornworts grow?

8-3: Seedless Vascular Plants General Characteristics of Seedless Vascular Plants: Vascular Tissue present Use spores to reproduce Examples: ferns, club mosses, and horsetails Vascular Tissue: Vascular Tissue allows plants to grow tall. Vascular plants are better suited for life on land because vascular tissue solves the problems of support and transportation. Transportation- food and water are transported quickly through the vascular tissue.

Support- Vascular tissue strengthens the plants body like a bundle of straws. Spores for Reproduction: Vascular plants still need to grow in moist surroundings. 1)Plant releases spores into surroundings 2)They grow into gametophytes 3)Gametophyte produces egg and sperm cells 4) There must be enough water for fertilization to occur.

Ferns First fern appeared on land 400 million years ago 12,000 species alive today Range in size from very tiny to tall trees. Fern Structure True stems, roots, and leaves. Stems are underground Leaves grow upward from stem Roots grow downward from stem Roots anchor the fern to soil to absorb water and nutrients. Stem

Fern Structure (cont.) The leaves are called fronds. Has a divided leaf structure. Cuticle helps the plant retain water. Fronds start off as a curled up structure often called “fiddleheads.” As they mature they uncurl into leaves (fronds). Reproduction in Ferns: The full grown fern with fronds is the sporophyte stage. Spores develop on the underside of fronds. Spores are released and wind/water carry them distances. If a spore lands in moist soil, it grows into the gametophyte stage.

The Importance of Ferns Ferns make nice houseplants because they are attractive and easy to grow. Ferns can help grow other kinds of plants. Some ferns are good to eat especially when they are fiddleheads. In some farms, ferns are grown to provide a place for bacteria to grow. That bacteria is used as a natural fertilizer.

Seedless Vascular Plants: Club Mosses and Horsetails Like ferns, club mosses and horsetails have true roots, leaves and stems. They also have a similar life cycle. There are only a few species alive today. Do not be confused by their name: Club Mosses are not mosses because they have vascular tissue! They look like tiny pine trees that grow in moist woodlands. Horsetails have stems that are jointed that have long needlelike branches that grow out in a circular pattern. The stem contain silica and that made them good for scrubbing pots and pans during colonial times.

Draw it! A frond is a leaf of a fern. It is a large leaf with a “divided leaf structure” meaning several long, thin leaves branch off of a central stem-like structure. What does a frond look like? DRAW IT!

Draw it! A fern is a vascular plant. It has vascular tissue that supports and transports materials. Vascular tissue is like a bundle of straws. What would it look like if you cut a fern stem in half and looked down at it? DRAW IT!

Draw it! A young fern frond is called a fiddlehead. It is a curled up baby frond that uncurls as the plant matures. It kind of looks like a new years eve horn that you blow into. DRAW IT!

Draw it! Spores develop in little containers on the underside of the fronds. They look like simple little brown dots, but they actually contain thousands of spores. What would a frond look like from underneath? DRAW IT!

8-4: Feeding the World Farmers need to be able to grow enough food for our growing world. In laboratories scientists are developing plants that are more resistant to insects, disease, and drought. They are also developing plants that produce more food per plant with new high-tech practices involving genetic engineering. Producing Better Plants Wheat, rice, and corn are the major sources of food for people on earth today.

One challenge for farmers is that these crops only grow in certain climates. Another challenge is that plants only produce a limited amount of food per plant. Genetic engineering of plants have helped to solve these problems. Plants can grow in a wider range of climates, be resistant to damage, and produce more food. Improving the Efficiency of Farms New technology using satellites help farmers with “precision farming”- knowing just how much fertilizer and water each field requires. Precision farming saves farmers time and money, and helps farmers maintain ideal conditions for growing.

Precision farming also benefits the environment because farmers use only as much fertilizer as the soil needs. Less fertilizer means less nutrients drain off into lakes and rivers- thus reducing the chance of algal blooms. Hydroponics In some areas of the world, poor soil does not support the growth of crops. In these areas, people can use hydroponics- a method where plants are grown in nutrient-rich solutions instead of soil. Unfortunately, hydroponics is expensive, but it does help grow crops in some areas.