| RESEARCH
REPORT
Food is one of the basic needs for all humans. Agriculture is the way
society produces enough food to feed everyone.
Plants
Plants are any living thing other than an animal. Plants are multi
cellular organisms. The cells include a nucleus, cell membrane, cell wall
and cytoplasm. Plants need carbon dioxide gas, water and energy from sunlight
to cause photosynthesis to make food. Plants are green because they have
a substance called chlorophyll in them. The greener the plant the more
chlorophyll Vascular plants have a system of tubes that transport food,
water and other materials. The largest vascular plant on earth is the Sequoia
trees. The Sequoia trees can grow to be over 110meters tall. Xylem tissue
carries water and nutrients up only from the roots of the plant. The cell
walls are thick; they help to support the plant. Phloem tissue transports
water, nutrients and waste up and down the plant. Herbaceous stems are
green and soft. Woody stems are rigid and hard. Non vascular plants don’t
have xylem or phloem so they can’t grow very large. They barely ever grow
more than 20centimeters tall and usually live in moist areas.
Different plants live for different amounts of time. Annuals live for
one year or less. They go from seed to flower to creating seeds to dying
and starting the cycle all over. Biennials live for two years. The roots,
stems and leaves grow the first year. The winter stems and leaves die but
the roots stay alive. They grow stems, leaves, flowers, and produce seeds
and die in the second year. Perennials live more than two years. In areas
with cool autumns and cold winters some perennials have dormancy.
In the autumn the leaves fall so, the stems and branches are bare in the
winter. Plants that loose leaves are called deciduous. Some perennials
are green all year. Pine trees loose a few of their leaves all year round
that’s why it looks like they are green all year.
There are three different ways that plants reproduce. In ferns and mosses
joining the male and female sex cells, gametes make plants from spores.
The female plants have long thin stalks with the capsule and the spores
inside. When the capsule bursts the spores come out. If the spores land
on a moist surface they will develop into moss plants.
Seeds from cones are called gymnosperms because they are seed bearing
plants that don’t produce flowers. The female cones are on the top of the
tree and have spiral woody cones. Each scale has female gametes. Male cones
are smaller and less woody. The male cones grow at the tips of the branches.
Male pinecones can produce millions of pollen grains. If carried by the
wind pollen grains may land on the female cones. The fertilization may
take place. During the fall and winter female cones fall off the trees,
when the scales open the seeds fall out. Some cones need fire or extreme
warmth to open the scales. Animals or wind sometimes scatter the seeds.
If the seed lands on a spot with the right conditions for growing the seed
will start to turn into a new pine tree.
Flowering plants are called angiosperms. There are about 230,000 Known
species of angiosperms. The parts of an angiosperm include sepals, petals,
stamens and pistils. Sepals protect the young buds. Petals are soft and
are usually bright colors. Petals surround the pistils and stamens. Some
flowers have pistils and stamens some have one or the other. Not all angiosperms
have bright petals. Grasses and some deciduous trees and shrubs don’t have
bright petals. The pistil is in the center of the flower and is the female
reproductive organ. The pistil has a stigma and ovary that contains the
female gametes. Stamens surround the stigma and are the male reproductive
organs. Stamens are filaments topped with small antlers containing male
gametes. Pollination occurs when pollen from the antlers comes in contact
with the stigma and moves down the pollen tube. When male and female gametes
join in the ovule the embryo forms. As the embryo grows, outer layers of
the ovule become tough layers and become the seed coat. The seed coat protects
the embryo when the embryo is released. The seed contains the embryo, the
stored food and the seed coat. The ovary surrounds the seed or the seed
gets larger and develops into fruit. Fruit is the ripened ovary of a flower
and contains one or more seeds. Cotyledons are the parts of a plant seed
that give nutrients to the embryo after germination. Monocot seeds contain
one cotyledon and dicot seeds contain two cotyledons. Monocot is short
for monocotyledon and dicot is short for dicotyledon. The embryo needs
stored food for germination. Cross-pollination occurs when pollen comes
from another flower. Most flowering plants characteristics encourage cross-pollination
such as bright colors, sugary nectars, and sweet odors. Hummingbirds, bees
and moths are attracted to different flowers because of colors, nectars
and smells. For example as a bee lands on a flower and goes to another
the pollen gets stuck to its legs. The pollen sticks to each flower as
it lands. Therefore cross-pollination is occurring. Wind also blows the
pollen from flower to flower. Some gardeners collect and provide pollen
using the dry tip of a paintbrush. By doing this we can grow flowers with
different characteristics.
Some problems with plants are listed here. Weeds are unhelpful plants
because they kill or weaken useful plants by towering over them and blocking
out the sun. Pollen can cause asthma and hay fever. Poison ivy and poison
oak causes skin rashes.
Photosynthesis is how plants make food. Photosynthesis means "putting
together with light." In green plants sunlight caught by chlorophyll enables
carbon dioxide from the air to join with water and minerals from the soil
and make food. This also releases oxygen into the air. Most photosynthesis
happens in small bodies called chloroplasts that are in the cells of plant
leaves. The chloroplasts contain chlorophyll which absorb sunlight. Energy
from the sun splits the water molecules into hydrogen and oxygen. The hydrogen
joins with the carbon from the carbon dioxide to make sugar. The sugar
helps a plant make the fat, protein, starch, vitamins and other materials
needed to survive.
Bean plants have compound leaves with three leaflets. The flowers look
like sweet pea flowers. The seeds are large and smooth. When the beans
are ripe the pod opens.
In Canada and the US the most important kind of is bean, the kidney
bean. The varieties include: the red kidney, the mottled pinto, and white
navy. Green shell beans are picked when they are full grown but before
they are hardened. Dry beans are very rich in proteins and carbohydrates.
Dry beans can be a sub for meat. Lima, Mung, and Soy beans are very important
in Asia. The scarlet runner bean has large bright red flowers, they are
grown for beauty. If the weather is cold the seeds may decay.
Mung beans are Native to India. They are heat loving annual requiring
120 days. They have been increased in popularity because they have been
used as sprouts in oriental dishes and salads. It takes 90 days of warm
weather for good yield in the garden. One cup of Mung sprouts is equal
to 35 calories, 22% of the daily vitamin A, 20% of the daily vitamin C.
Mung beans are used for sprouting and are canned. 15,000 to 20,000 pounds
are used annually and out of that three quarters is imported to North America.
Farmers are advised to inaculate with appropriate Rhizobium before sewing.
Fertilize like you would fertilize field beans. Because there aren’t any
herbicides registered weed management consists of choosing a clean field
and inter-row cultivation. Seed-corn maggots and cut worms may cause significant
injury. Some diseases that the Mung bean can get are: bacterial blight
and sclerotinia . To reduce the risk of them getting a disease use disease
free seed, adequate crop rotation and row-crop production. Store the picked
seeds at 12% moisture. Potential quality problems include cracked seeds,
frost-damaged seeds and dirt.
Some of the pests of beans are the Mexican bean beetles, aphids and
Leafhoppers.
Some of the diseases of beans are anthrarnose, and powdery mildew.
Thermodynamics
Thermodynamics is a branch of physics that deals with the relations
between heat and other forms of energy, and the conversion of one into
the other.
Heat is a form of energy that consists of the motion of molecules of
a substance. This energy can pass from one object to another and, when
absorbed, produces an increase in temperature.
The first law of thermodynamics states that energy is a system and cannot
be created or destroyed. The second law of thermodynamics states that heat
only moves from warmer to less warm objects.
The sun is the most important source of heat. Heat also comes from volcanoes,
hotsprings(geysers). Heat comes from some chemical reactions, like oxidation.
Heat also comes from friction like when you rub two rocks together it causes
friction and heat. For example when you strike a match is causes friction
and catches the phosphorus on fire.
Heat is one of the most important energy forms. We use heat for many
things like warming homes, cooking food and heating water. Heat can make
turbines spin which makes electricity. Factories melt and bend metal with
heat.
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