Biology ch1

• Plants make food through


  Photosynthesis
• Inorganic substances used by autotrophs to make food

  • CO2
  • Water
• Plants need water and carbon dioxide in addition to sunlight and chlorophyll to make food by photosynthesis
• Fungi obtain their food from dead and decaying plants and animals. Such type of mode of nutrition is called saprotrophic nutrition
• Organisms with different modes of nutrition

  • Fungi - saprophytic mode of nutrition
  • Leech - parasitic mode of nutrition
  • Amoeba - holozoic mode of nutrition
• To perform vital life processes like respiration, chemical energy is used by living organisms
• Food is the basic requirement of all living organisms to get energy and to carry out their activities
• Raw materials needed by plants

  • Nitrogen
  • Magnesium
  • Iron
  • Phosphorus
• In photosynthesis, Oxygen gas is produced
• Boiling the leaf in alcohol helps to remove chlorophyll during starch testing
• Life Process

  1. Photosynthesis

  2. Respiration

  3. Nutrition
• Conditions necessary for photosynthesis

  • Sunlight
  • Chlorophyll
• The food prepared in the plant by the process of photosynthesis is glucose (A) then it gets stored in plant leaves in the form of starch (B)
• Alcohol is used to remove chlorophyll from a green leaf during photosynthesis experiments
• In photosynthesis, Carbon dioxide gas is used
• Chlorophyll


  Pigment in leaves that absorbs sunlight energy
• Green plants are autotrophs because they can make their food themselves
• Chloroplast


  Organelle in plant cells where photosynthesis occurs
• The colour of chlorophyll pigment is green
• Amoeba's process of obtaining food is called phagocytosis
• Guard cells control the opening and closing of stomata in plant leaves
• Chlorophyll is mainly present in the chloroplast, which is mainly present in the leaves of the plant
• Control of stomata

  Each stomata is surrounded by a pair of guard cells. Guard cells regulate the opening and closing of stomata
• Phagocytosis is the process of obtaining food in amoeba
• Herbivores are animals that are only plant eaters
• Carnivores are animals that are only meat eaters
• Amoeba engulfs food particles by forming finger-like projections called pseudopodia
• Chlorophyll is the green pigment present in the leaves of plants. It is necessary for the process of photosynthesis
• Omnivores are animals that eat both plant and meat
• Groups animals can be divided into based on eating habits

  • Herbivores
  • Carnivores
  • Omnivores
• In amoeba, digestive enzymes break down food in the food vacuole
• Order of processes in animal nutrition

  Ingestion, digestion, absorption, assimilation, egestion
• Undigested food in amoeba is egested when a sufficient amount collects inside the cell and is thrown out by rupturing the cell membrane
• Paramecium uses cilia to move food particles into its mouth
• Saliva contains salivary amylase which acts on starch and breaks it down into sugar
• Peristaltic movement is the contraction and relaxation of muscles in the digestive tract to move food through the system
• The food pipe is also called the oesophagus, a long muscular tube running from the mouth to the stomach
• Absorption of digested food occurs in the small intestine, while absorption of water from remaining indigestible food occurs in the large intestine
• Saliva is mixed with food in the mouth during chewing by the teeth
• The inner surface of the small intestine has finger-like projections called villi which help in absorbing digested food