Download NUTRITION IN PLANTS Nutrition • Living organisms need energy for

NUTRITION IN PLANTS
Nutrition
• Living organisms need energy for growth and maintenance. The
energy is derived from good.
Autotrophic nutrition
• Green plants are autotrophic and manufacture their own food
through the process of photosynthesis.
• Photosynthesis involves the use of the energy in sunlight to
convert water and carbon dioxide into carbohydrates (starch) and
oxygen.
Photosynthesis
• Photosynthesis has two stages: the light reaction and the dark
reaction..
• It takes place in the chloroplasts of leaves.
• Each chloroplast contain grana and stroma. Light reactions take
place in the grana while dark reactions occur in the stroma.
• Carbon dioxide is obtained through stomata present mostly on the
underside of leaves, and water from the soil through the roots of
the plant.
Heterotrophic nutrition
•
Non-green plants practise heterotrophic nutrition because they are unable to manufacture their
own food.
• Heterotrophic plants are of four types, namely, parasitic, saprophytic, carnivorous and symbiotic.
Parasitic plants
• Parasitic plants absorb food from another growing green plant called the host.
• They develop special roots called haustoria which penetrate into the tissues of the host plants.
Saprophytic plants
• Saprophytic plants are plants that live off rotting material.
• They have no green leaves, often no leaves at all.
Carnivorous plants
• Carnivorous plants are also called insectivorous plants because they consume mainly insects.
• They are green plants but due to the soil being deficient in certain nutrients they have to resort to
other means of obtaining these nutrients.
• The specialized structures they develop to catch insects and other small animals are all
modifications of their leaves.
Symbiotic plants
• Certain plants species which live with another species and share their food resources are called
symbiotic plants.
• In a symbiotic arrangement one organism is an autotroph and manufactures its own food. The
other organism absorbs water and minerals for the autotroph and, in return, obtains food from it.
NUTRITION IN ANIMALS
• Holozoic nutrition involve the following five processes : ingestion,
digestion, absorption, assimilation and egestion.
• Most animals are holozoic.
• Saprozoic nutrition involves feeding on the dead remains of living
organisms .
• In parasitic nutrition, an organism for a part or all of its life derives its
food from a living organism of another kind .
• Mutualistic nutrition involves an interaction between two organisms in
which both are benefited. One organism derives food from the other
while the other is also helped in some way by the former.
Nutrition in amoeba
• The type of nutrition in Amoeba is called phagocytosis.
• When Amoeba comes in contact with a food organism it forms a food
vacuole around it which encloses and ingests the food.
• Digestion is simple and direct. Digestive juices dissolve the prey and it
is absorbed and assimilated in solution form.
Nutrition in humans
• Humans are omnivores meaning they can eat both plant and animal food.
• The process of digestion begins in the mouth where it is mixed with saliva.
• The major part of the digestive process takes place in the stomach and the small intestine.
• The main job of the intestines is to absorb the nutrients.
• Solid waste is stored in the rectum and passed out of the anus.
Nutrition in ruminants
• Ruminants have a four-chambered stomach made up of the retculum, rumen, omasum and
abomasum.
• Absorption begins in the rumen and the omasum but the majority of the nutrients are
absorbed in the small and the large intestine.
• Faeces are stored in the rectum and excreted out of the anus.
Circulation and respiration
• The circulatory system helps to transport the absorbed nutrients to the rest of the body.
• The respiratory system helps to obtain oxygen that is necessary to break down glucose to
release energy.
Types of teeth
• The four different types of teeth in animals are incisors, canines, premolars and molars.
• In humans two sets of teeth arise in their lifetime: the milk teeth and the permanent teeth.