Section 6.1 Comparing Plants & Animals p. 164-168
Major Similarities: They are both multi-cellular, eukaryotes. Their sizes both range from microscopic to very large. Major Differences: How they obtain food. Movement Evolution Animals evolved in water, the only major groups found on land are the insects, spiders and mollusks (snails). Plants evolved on land. Trees and grasses dominate the land.
PLANTS Plants generally are rooted in one place an do not move on their own ANIMALS Most animals have the ability to move fairly freely. Plants contain chlorophyll and can make their own food Animals cannot make their own food and are dependent on plants and other animals for food. Plants give off oxygen and take in carbon dioxide given off by animals. Plants cells have cell walls and other structures differ from those of animals. Plants have either no or very basic ability to sense. Animals give off carbon dioxide which plants need to make food and take in oxygen which they need to breathe. Animal cells do not have cell walls and have different structures than plant cells Animals have a much more highly developed sensory and nervous system.
Section 6.2 Kingdom Plantae p. 169-181
Kingdom Plantae Plants Cell Type: all are eukaryotic. Cell Wall: their cells all have a rigid (stiff) cell wall, composed of cellulose. Body Form: all are multicellular. Nutrition: all are autotrophic and make their own food using photosynthesis. They use sunlight as an energy source and CO 2 as a source of structural carbon. This means that their energy and carbon come to them. They do not have to move to acquire either. Reproduction: Asexual & Sexual. Locomotion: Non-motile. No movement.
Examples from the Kingdom Plantae: 1. Bryophytes Mosses, liverwarts, hornwarts 2. Ferns Ferns, whisk ferns, club mosses, horsetails 3. Gymnosperms Conifers, evergreens 4. Angiosperms Flowers, deciduous trees, peas
Plants first appeared about 400 million years ago! The ancestors of plants were algae. Made up of three parts: Leaves- provide surface area for absorbing sunlight. Stem- provides support for the leaves. Roots- anchors the plant and absorbs water and nutrients from the soil.
Plants are classified based upon two major characteristics: 1. Whether they have vascular tissue or not. Vascular tissue - tissues used to efficiently transport food or water through a plant. (present in Ferns, Gymnosperms and Angiosperms) 2. Their methods of reproduction. How plants carry out sexual reproduction and how they develop into new plants. whether they reproduction by using male sperm or male pollen whether they develop from spores or seeds (spore development is less advanced) what types of reproductive organs they have present (flowers, cones, antheridia, ovule, etc.)
gamete - a cell involved in sexual reproduction; male or female sex cell such as sperm or eggs. spore - a single, specialized reproductive cell released from a parent plant which can grow into a new plant. (produced by the Bryophytes and the Ferns) seed - a multicellular structure containing several specialized tissues and a partially developed, immature plant embryo. It contains a food supply for the embryo and is protected by a tough, outer coat. (produced by the Gymnosperms and Angiosperms) pollen grain - the male gamete of a Gymnosperm or an Angiosperm. It is a protective capsule which contains the male gamete. It is transported by wind or carried on insects or animals. (produced by the Gymnosperms and Angiosperms)
Two Major groups of plants: VASCULAR These plants have vascular tissue made up of: xylum (transports water) and phloem (transports nutrients) The xylum and phloem are comparable to our circulatory system because it transports water, dissolved nutrients and sugars to all parts of the plant. All plants are vascular except mosses, liverworts and hornworts (Bryophytes). NON-VASCULAR- These plants do not have vascular tissue. They also lack or have poorly developed roots, stems and leaves. They include: Mosses, Liverworts, Hornworts (Bryophytes).
1. The Bryophytes - The primitive plants mosses, liverworts, hornworts ( see p. 170) Nonvascular - have no vascular tissue. No true roots, stems or leaves ( true roots, stems and leaves have vascular tissue) They are restricted to a very tiny size; tallest mosses are just 8 cm tall. This is because without vascular tissue to speed up the process, they must rely on diffusion to pass water and food from cell to cell throughout their bodies. The diffusion process is slow without the aid of vascular tissue so small size is a must. They still depend on the presence of water for sexual reproduction to occur so they are restricted in their habitat to places that are wet enough to provide the proper conditions for this type of reproduction to occur. They still use sperm cells to reproduce. This is a primitive process for land plants to use.
Male Bryophyte plants release sperm cells during rainfall or a heavy morning dew. The sperm must swim through the water coating on the plants and soil surface to reach female plants where they fertilize eggs. The eggs are contained in an open structure called an archegonia. They are not protected well. Archegonia - the egg producing structures of a bryophyte or fern. Antheridia - the sperm producing structures of a bryophyte or a fern. The moss life cycle has two body forms, the sporophyte and the gametophyte. (see diagram p. 170). They have a dominant (meaning that it is larger, lives the longest and is more complex) gametophyte generation. Gametophyte- is a plant that produces gametes, egg or sperm.
Non vascular plants include mosses (Bryophytes), hornworts, and liverworts. These have no vascular tissue and most get nutrients through diffusion and osmosis. These plants grow low to the ground. Non vascular plants have no roots but they do have structures called rhizoids which anchor them to the ground. There are about 16 000 species of bryophytes. They are common in moist, shaded areas.
Examples of Bryophytes: Mosses, liverwarts, hornwarts 2/26/15 14
2. The Ferns ( see p. 171) Ex. ferns, whisk ferns, club mosses, horsetails. They are vascular plants but still have primitive reproduction - use sperm to fertilize eggs so they are restricted to a moist habitat. They also use spores to reproduce instead of seeds. Spore reproduction is more primitive than using seeds. They have a dominant sporophyte generation. (the dominant generation is the one that is largest and lives longest). A sporophyte most times refers to a plant that produces spores or pollen.
Seedless vascular plants were the first vascular plants to grow on Earth. These include ferns and their relatives. These plants reproduce by spores. They are able to grow tall and survive in a variety of environments. Examples include whisk ferns, club mosses, horsetails, and ferns.
Seed producing vascular plants are divided into two main groups: gymnosperms (conifers and relatives) and angiosperms (flowering plants). The seeds contain the embryo and a food supply. The embryo includes a root, a shoot, and one or two seed leaves. The seeds allow the plant to reproduce sexually without water. It also provides protection during the dormant period.
3. The Gymnosperms - ex. Conifers and evergreens Name comes from the Greek word Gymnos which means naked seed. This is because their seeds are not produced inside of fruits but are exposed for fertilization on opened female cones. They are vascular plants. They are seed producing plants with no flowers. Their reproductive organs are cones. Male cones produce pollen. Female cones produce eggs. Theses plants are not dependant on water for reproduction. When fertilization is completed, theses plants produce seeds to complete reproduction. They have a dominant sporophyte generation.
Conifers or Evergreens A Tracheophyte (have vessels to move fluids) Coniferous plants Seeds are said to be naked and are born inside of cones There are both male and female cones Include pines, firs, spruces, hemlocks Sometimes called evergreens because they do not tend to lose all their needles at one time Leaves are needle-like or scale-like
Gymnosperms have roots, stems and leaves. The seeds are on the surface of the cones. These include pines, firs, yew, spruce, cedars, redwood, and other large trees. They are able to reproduce without water and they protect the stem from losing water by covering it with bark. They have needle like leaves with a thick, waxy covering to reduce evaporation. The shape also reduces water loss. The leaves are lost and replaced year round. By keeping their leaves, they are able to begin photosynthesis as soon as the weather becomes warmer. They also do not need to use energy to grow a complete set of new leaves.
Examples of Gymnosperms Black Spruce Cone / Foliage 2/26/15 21
Eastern White Pine Cone and Tree 2/26/15 22
Jack Pine Tree and Cone 2/26/15 23