When you have finished this page, try the Flowers Quiz.
A flower is a part of the plants called angiosperms that holds the plant’s reproductive organs. They are formed from buds. The flower is attached to the tip of a stem at a point called the receptacle.
There are four basic flower parts. They are, going from the outside of the flower to the inside
Sepals: A group of leafy like parts at the base of the flower altogether called the calyx.
Petals: The colorful parts of the flower arranged within the sepals – altogether called the corolla.
Stamens: The male part of the flower within the petals or corolla. They contain sacs holding pollen, the male sex cells and are called anther sacs.
Carpels: The female part of the flower at its very center altogether called the ovary and also the pistil. At the bottom of the pistil are the eggs or ovules which are the female sex cells. When these tiny ovules become fertilzed with pollen they form seeds. The ovary then develops into fruit.
The number of flower parts differs from flower group to flower group and is but one of the ways to tell the different plants apart. In the monocots, or plants whose seeds have one seed leaf, the parts tend to come in groups of threes. In dicots or plants with seeds with more than one seed leaf, the parts tend to come in twos or fours or five.
Flowers can be without stamens, or without carpels or can have both.
When you are done with this page, try the Stems Quiz.
The stem is a part of the plant that holds up other structures such as the leaves and flowers. This is important as the leaves need to be held up to the sun to get its light for photosynthesis and the flowers need to be held up to be available for pollination. Stems also carry water and minerals up from the roots to the leaves to help with photosynthesis and take food back down to be stored and distributed to the plant as it has need. The tubes in the stem that take the water and minerals up into the plant are the xylem and the tubes that carry the food back down are called the phloem.
Stems can be of several sorts, herbaceous and woody. The herbaceous stems are green and fairly bendable. The woody stems as their name implies, are covered by bark. The herbaceous stem has more pith for its size. The cambium which causes woody stems to get bigger in width is not as active in the herbaceous stems. Most herbaceous plants are annuals or planted yearly. The herbaceous stem has little notches where leaves develop. Woody stems have scars where twigs and fruit have dropped off and little openings for transpiration.
There are different sorts of aerial stems or stems that are upright. They include tendrils, runners and thorns. Succulents are plants with bigger fleshy stems that help plants retain water in dry areas. Some stems are underground such as bulbs and tubers. There are also stems that cannot hold themselves up, but need to be supported.
Stems are valuable to man as a source of food and its wood is used for many products. The sap from many stems is used for resins and latexes.
When you have finished this page, try the Roots Quiz.
The root is the part of a plant that is usually found underground but can also be above ground.
Roots’ jobs are:
- To absorb or take in water and minerals from the ground
- To hold the plant in place.
- To store food for the plant.
- To prevent soil erosion.
There are two inds of root systems. One is the tap root system. In this system there is a main root larger than the other branching roots. The other is the diffuse root system. In this system there are many thin roots with smaller root branching out..
Tap roots are found in most trees and the carrot, parsnip, radish, beet, and dandelion. The grasses such as corn and rye have diffuse roots.
Root systems can be far larger the above ground parts of the plant. They tend to grow in length rather than width. The roots contain a cap at their end that is replaced periodically as the root grows through the soil.
Within the roots themselves are areas that store food and also tubes called xylem and phloem that take in water and minerals up to the leaves and to bring food manufactured in the leaves back down for nourishment and storage. There are tiny root hairs that maximize the water and minerals that the root can take in or absorb.
Roots of plants are helpful to man because they help the plant live and also man eats many different kinds of roots.
When you have finished this page, try the Leaves Quiz.
The leaf is a part of the plant that is charge of making food for the plant. This food making process is called photosynthesis.
Parts of the leaf
The leaf consists of the following parts:
Petiole – a thin stalk that connects the blad of the leaf to the plant’s stem. These veins are called
Blade – a thin, flat part of the leaf that extends off the end of the petiole. It is green as it contains cholorophyll which is necessary in making the plant’s food..
The blade contains veins which help bring in the water necessary for photosynthesis and to transport food out to all parts of the plant. The xylem is responsible for water transportation and the phloem for food.
The blade also has several layers. The top layer is covered with a waterproof coat called the cuticle. Both the upper and lower layer contain paired cells called guard cells. These guard cells manage the stomata, little openings in the leaf that allow for the taking in of carbon dioxide and the emission of oxygen during photosynthesis. Water vapor is also emitted in a process called transpiration.
In between the top and bottom layers of the blade are cells that are full of chlorophyll that is essential for the plant to make its food during photosynthesis.
Leaves come in a variety of shapes, sizes, color, and textures. Leaves can be grouped as simple with one blade or compound with many leaflets. The edges of leaves can be smooth, have jagged edges referred to as toothed or scalloped edges referred to as lobed edges. Leaves can also be divided into how their veins are arranged. The leaves of plants referred to as monocots have leaves that run parallel to each other off one central vein. Those that are referred to as dicots have leaves with veins that branch out two different ways.Pinnate have one main vein called the midrib, and smaller branching veins. Palmates have several large veins branching from the leaf base into the blade.
Some leaves have special features such as spines and bud scales to protect them. Some are climbing (tendrils). Others catch insects. Some store water. These are called succulents or store food such as bulb scales.
Leaves contain other substances besides chlorophyll that give the leaf color. These substances are called pigments and cause leaves to turn colors in autumn. These leaves are on deciduous trees and fall off and die. New ones grow back in the spring. Conifers or trees that bear cones can keep their needles for years and grow new ones as soon as they lose them.
When you have finished this page, try the Angiosperm Quiz.
Angiosperms are flowering plants. Angiosperms are the biggest group in the plant kingdom. They have true roots, stems, leaves and flowers. They also have seeds.The seeds are formed when an egg or ovule is fertilized by pollen in the ovary. The ovary is within a flower. The flower contains the male and/or female parts of the plant. Fruits are frequently produced from these ripened ovaries.
Angiosperms are more highly evolved that the algae, mosses, fungi and ferns. Their advanced structures allow angiosperms to thrive on land. They have roots that hold the plant in place and take in needed minerals and water. They have leaves that are the major food makes for the plant. They have stems that hold the plants up and move the nutrients and water about the plant.
Angiosperms the primary food source for animals and provides oxygen for us to breathe. They provide lumber for buildings and other objects, fibers for clothes, are the basis for many drugs, etc..
When you are finished with this page, try the Gymnosperm Quiz.
Gymnosperms are a type of plant that reproduce by a seed that is not enclosed as with angiosperms who have seeds contained flowers. Many of these plants are conifers or cone bearing plants. Gymnosperms are found throughout the world. They have roots and stems. Their leaves are in the form of needles in conifers.
At the time of pollination, the pollen or male pollen grains fall among the cone scales until they fall on to the ovules. As the cone grows up, it gets bigger and the seeds that are created by the male pollen and female parts are seen. Most conifers are evergreens or always green and they do not shed their leaves as deciduous plants do but retain their needles for quite a while. When the needles fall off, they are quickly replaced.
When you have finished this page, try the Ferns Quiz.
Ferns are a large group of plants. There are several thousand types of ferns and they are found throughout the world. They are mostly found in tropical rain forests.
Ferns do not have true leaves as many plants do, but structures called fronds. These fronds are split down into leaflets called pinnae. These fronds are green and the fern gets its food via photosynthesis.
Ferns reproduce by spores in an alternating generations. The fern itself is the sporophyte, which produces asexual spores. The spores are held in special sacs scattered on the bottom part of fronds. These sacs look like specks of dirt. Today no ferns have seeds but ferns of early times seem to be precursors to today’s seeded plants and trees.
Ferns are used for decorations and tree ferns in the tropics for buildings. However, much of today’s coal is the result of the decay of ancient ferns which were the major plant forms at that time.
When you have finished this page, try the Fungi Quiz.
Fungi are a group of organisms that at one time were considered a part of the plant kingdom and thus is being discussed at this site. Today they are in a special group called eukaryo.
This group included yeast, molds, mildews and mushrooms. It is not hard to see why they are not classified within the plant kingdom any longer. They do not make their own food as green plants do, but frequently live off of other living things which makes them parasites or symbiotic, depending on their relationship with the other living organism. Parasites are organisms that live off another living thing and do not help them in return. In symbiosis, two organisms live off of one another and help one another as they live off of one another.
Fungi also do not have the true roots, stems and leaf structures of many plants or structures that resemble these.
Fungi are found many places. Fungi have this in common. They take in or absorb their nutrition through mycelium, a structure that is important in this process. Fungi reproduce sexually or asexually by spores or in the case of yeast by budding or by fission. In budding, an organism grows a part of of its main body and this new growth eventually breaks off to become a new organism. In fission, an organism literally splits in half, sharing important nucleic information to form a new organism. Both budding and fission are more typical of lower forms of living things as a method of reproduction. Sexual reproduction is more typical of higher forms of living organisms.
When you have finished this page, try the Mosses Quiz.
Mosses and liverworts are a simple type of green land plant. They have existed on the earth for millions of years. They do not have the true roots, stems with xylem and phloem and leaves of more developed plants. They do have a simple form of roots called rhizomes and simple structures like leaves. Mosses are found in moist areas and do not grow vertically too high but can spread out to be a yard long. They are found on forest floors and appear as a sort of living carpet. Mosses make their own food through photosynthesis.
Mosses reproduce or make more of themselves by branching and breaking into pieces. They also regenerate from parts of leaves or stems, and by spores.
Mosses are valuable in the form of peat moss and sphagnum used for fuel. Some animals also eat mosses. Mosses break down soil to let loose nutrients. They are important in preventing erosion.
When you have finished this page, try the Algae Quiz.
Algae are a large group of living things, at one time thought to be a type of plant. They have many of the characteristics of plants. They have chorophyll and make their own food. However they do not have roots, stems, leaves or flowers and are found mostly in all kinds of watery places worldwide.
Today algae are now more often grouped as protista The study of algae is called phycology.
Algae can be one celled as in diatoms or euglena, or many celled. Some examples of multi-celled would include the ball shaped Volvox, the ribbon shaped spirogyra, seaweed. kelps. Some of the algae can reach sizes of several hundred feet.
Algae are major suppliers of food and oxygen within water communities. They are important in help provide petroleum. Certain algae are also eaten by humans as well.
Algae reproduce in a variety of ways. The simplest forms of algae reproduce by simple cell division. Others reproduce by spores, fragmentation or reproduce sexually.
Many algae get their names by the pigments or cells that color them such as blue-green algae, brown or red seaweed, etc.