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12. (a) (i) Distinguish between the terms excretion and egestion by writing a sentence about each term - Leaving Cert Biology - Question 12 - 2016
Question 12
12. (a) (i) Distinguish between the terms excretion and egestion by writing a sentence about each term. (ii) Suggest how excretion may occur in simple organisms suc... show full transcript
Worked Solution & Example Answer:12. (a) (i) Distinguish between the terms excretion and egestion by writing a sentence about each term - Leaving Cert Biology - Question 12 - 2016
Step 1
Distinguish between the terms excretion and egestion by writing a sentence about each term.
Answer
Excretion is the process of removing metabolic waste products from the body, such as carbon dioxide and urea. In contrast, egestion refers to the elimination of undigested or unabsorbed material from the digestive system.
Step 2
Suggest how excretion may occur in simple organisms such as Amoeba.
Answer
In simple organisms like Amoeba, excretion occurs primarily through diffusion. Waste materials are expelled through the cell membrane, aided by the contractile vacuole, which helps in the removal of excess water and waste products.
Step 3
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Step 5
Describe the role of ADH (vasopressin) in human excretion.
Answer
ADH, or vasopressin, plays a crucial role in regulating water balance in the body. It is produced in response to high salt levels or low water levels, acting on the kidneys to make collecting ducts more permeable, allowing more water to be reabsorbed into the bloodstream. This leads to a decrease in urine volume and helps maintain hydration.
Step 6
Suggest two structures in flowering plants which play a role in excretion.
Answer
Two structures in flowering plants that play a role in excretion are the stomata and lenticels. Stomata facilitate gas exchange, allowing the release of oxygen and the uptake of carbon dioxide, while lenticels allow for gas exchange in plant tissues, aiding in the removal of waste gases.