mid term

• Plants are stationary, so their energy requirement is less and the process of respiration is slower compared to animals.- true
• In leaves, gases enter through the stomata. After gases enter a leaf, intercellular gas exchange takes place. This occurs in the air space between spongy mesophyll layer
• Stomatal opening and closing depends on changes in the turgor of the guard cells. When water flows into the guard cells by osmosis, their turgor increases and they expand. Due to the relatively inelastic inner wall, the guard cells bend and draw away from each other, so the pore opens. 
• If the guard cells loose water, the opposite happens and the pore closes. The guard cells lower their water potential to draw in water from the surrounding epidermal cells, by actively accumulating potassium ions. This requires energy in the form of ATP which, is supplied by the chloroplasts in the guard cells.
• •       In the light, the guard cells absorb water by osmosis, become turgid and the stoma opens.
• •       In the dark, the guard cells lose water, become flaccid and the stoma closes.
• Gas exchange also occurs in stem and roots. Stem of woody plants contain lenticels which are loosely packed cells that permits exchanges of gases. In roots, it occurs across moist membranes of the roots hair and other epidermal cells
• For higher plants to sustain their metabolic processes, inorganic nutrients are obtained from the environment via soil, air and water.
• Classifying elements as essential for plant growth is based on visual diagnosis, plant analysis, biochemical tests, and soil test.- true
• Respiratory systems allow animals to move oxygen (needed for cellular respiration) into body tissues and remove carbon dioxide (waste product of cellular respiration) from cells.
• Blood glucose levels does alter the rate of breathing by influencing the respiratory centers of the brain. -false/ it doesnt alter
• Ventilation is the mechanics of breathing in and out.
• Air entering the lungs contains less oxygen and less carbon dioxide than the blood that flows in the pulmonary capillaries. -false/ contains more oxygen
• •      Hemoglobin binds to oxygen that diffuses into the blood stream.
• •      Oxygen diffuses out of the capillary and into cells, whereas carbon dioxide diffuses out of cells and into the capillary. There is a partial pressure of oxygen, when diffused in the environment and in the blood.
• Oxygen diffuses into the red blood cells.
• Carbon dioxide diffuses into the alveolus.
• Carbon dioxide diffuses from the blood into the alveoli because there is a higher concentration of carbon dioxide in the blood compared to the lungs.

   
• The partial pressure of carbon dioxide is high in the pulmonary capillaries and low in the alveoli.
• •      Asthma narrows the airways by causing an allergy-induced spasms of surrounding muscles or by clogging the airways with mucus.
• •      Bronchitis is an inflammatory response that reduces airflow and is caused by long-term exposure to irritants such as cigarette smoke, air pollutants, or allergens.
• •      Cystic Fibrosis is caused by mutation of a single gene, the CFTR gene, which controls salt balance in the lungs.
• In our lungs, Cilia and mucus are very significant because oxygenated air moves easily through tubes helped along by cilia.
• Mucus traps irritants in our airways.
• Water is an essential requirement for plants’ survival. Water uptake allows plants to metabolically utilize the chemical compounds and micronutrients obtained from the surrounding soil.
• symplast route – through plasmodesmata
• apoplast route – along cell walls
• •       Xylem vessels are composed of dead lignified cells connected end to end. This allows the transport of water and minerals in the upward direction.
• •       Phloem is composed of sieve tubes, which are closely associated with companion cells facilitate movement of materials across the cell cytoplasm. These tubes carry the products of photosynthesis in a bidirectional movement to ensure supply of materials for the growth of buds, roots and other plants parts.
• . substrate-feeders – – animals that live in or on their food source. Examples: earthworms that feed through the soil where they live in; caterpillars that eat through the leaves where they live on.
•  Filter - feeders– –included many aquatic animals which draw in water and strain small organism and food particles present in the medium. Examples: whales and coelenterates
• Fluid – feeders – suck fluids containing nutrients from a living host. Examples: mosquitoes, leeches, head lice, aphids
• bulk-feeders –– eat relatively large chunks of foods and have adaptations like jaws, teeth, tentacles, claws, pincers..
• •       Food vacuoles in unicellular organisms – these fuse with lysosome that contain hydrolytic enzymes.
• •       Gastrovascular cavity or incomplete digestive system – composed of a single opening through which food is taken in and where wastes are disposed of; it is a saclike body cavity.
• •       Complete digestive system – essentially like a tube with an opening at one end for taking in food (mouth) and an opening at the other end where unabsorbed waste materials are eliminated (anus).
• Vertebrate stomach is a saclike organ that evolve to store food, its cells secrete hydrochloric acid and it is the initial site of protein digestion.
• •       Liver – secretes bile for emulsifying fats
• •       Gall bladder – stores bile produced by the liver\
• •       Pancreas – secretes enzymes that break down all major food molecules; secretes buffers against HCl from the stomach; secretes the hormone insulin for control of glucose metabolism