Life Processes in Living Organisms Part -1
Short Questions
1. What are the main sources of energy for living organisms?
Answer: Carbohydrates, fats, and lipids are the primary sources of energy for living organisms.
2. Which cell organelle harvests energy from food?
Answer: Mitochondria are the cell organelles that harvest energy from food for cellular use.
3. What is necessary along with foodstuff for energy production?
Answer: Oxygen is essential along with foodstuff for producing energy in living organisms.
4. Which system transports food and oxygen to cells?
Answer: The circulatory system transports food nutrients and oxygen to cells in the body.
5. What type of organisms prepare their own food?
Answer: Autotrophs, such as plants, prepare their own food through photosynthesis.
6. How much energy is obtained from one gram of carbohydrates?
Answer: One gram of carbohydrates provides 4 kilocalories of energy to the body.
7. What is cellular respiration?
Answer: Cellular respiration is the process of oxidizing food in cells to produce energy.
8. What are the two types of cellular respiration?
Answer: The two types of cellular respiration are aerobic and anaerobic respiration.
9. Where does glycolysis occur in a cell?
Answer: Glycolysis occurs in the cytoplasm of the cell during cellular respiration.
10. What is formed from glucose during glycolysis?
Answer: Glycolysis forms pyruvic acid, ATP, NADH2, and water from a glucose molecule.
11. What is the Krebs cycle also known as?
Answer: The Krebs cycle is also known as the tricarboxylic acid cycle in biology.
12. Where does the Krebs cycle take place?
Answer: The Krebs cycle takes place in the mitochondria of the cell.
13. What is ATP called in cells?
Answer: ATP is called the energy currency of cells due to its role in energy transfer.
14. What happens to pyruvic acid in anaerobic respiration?
Answer: Pyruvic acid is converted into organic acids or alcohol during anaerobic respiration.
15. What accumulates in muscle cells during anaerobic respiration?
Answer: Lactic acid accumulates in muscle cells during anaerobic respiration, causing fatigue.
16. What are proteins made up of?
Answer: Proteins are made up of amino acids linked together in a chain.
17. How much energy is obtained from one gram of proteins?
Answer: One gram of proteins provides 4 kilocalories of energy to the body.
18. What process converts excess proteins into glucose?
Answer: Gluconeogenesis is the process that converts excess proteins into glucose.
19. What are lipids formed from?
Answer: Lipids are formed by the chemical bonding of fatty acids and alcohol.
20. How much energy is obtained from one gram of lipids?
Answer: One gram of lipids provides 9 kilocalories of energy to the body.
21. What are phospholipids used for in cells?
Answer: Phospholipids are used to produce plasma membranes in cells.
22. Which vitamins are fat-soluble?
Answer: Vitamins A, D, E, and K are fat-soluble vitamins in the body.
23. Which vitamin is necessary for producing FADH2?
Answer: Riboflavin, also known as Vitamin B2, is necessary for producing FADH2.
24. What percentage of water is present in blood plasma?
Answer: Blood plasma contains approximately 90% water by weight.
25. Why are fibers important in the diet?
Answer: Fibers aid in digestion and help remove undigested substances from the body.
26. What are the two main types of cell division?
Answer: The two main types of cell division are mitosis and meiosis.
27. Where does mitosis occur in the body?
Answer: Mitosis occurs in somatic cells and stem cells of the body.
28. What is the first step of karyokinesis in mitosis?
Answer: Prophase is the first step of karyokinesis in the mitosis process.
29. What happens to chromosomes during anaphase of mitosis?
Answer: Sister chromatids separate and move to opposite poles during anaphase.
30. What type of cells are formed by meiosis?
Answer: Meiosis forms haploid cells, such as gametes and spores, in organisms.
Long Questions
1. What is the role of different organ systems in energy production?
Answer: Organ systems like digestive, respiratory, and circulatory work together to provide energy. The digestive system breaks down food into nutrients, and the respiratory system supplies oxygen. The circulatory system transports these to cells, where mitochondria produce energy.
2. How do plants contribute to the nutrients we consume?
Answer: Plants, being autotrophs, prepare their own food and store nutrients in parts like fruits, leaves, and roots. Humans and animals eat these parts to get carbohydrates, proteins, and vitamins. These nutrients are essential for energy and body functions.
3. What is cellular respiration, and why is it important?
Answer: Cellular respiration is the process where cells oxidize food to produce energy in the form of ATP. It happens in two ways: aerobic (with oxygen) and anaerobic (without oxygen). This energy is vital for all life processes in living organisms.
4. How does glycolysis contribute to energy production?
Answer: Glycolysis breaks down a glucose molecule in the cytoplasm into two pyruvic acid molecules. It also produces two ATP and two NADH2 molecules, which store energy. This is the first step in cellular respiration for energy production.
5. What happens during the Krebs cycle in mitochondria?
Answer: The Krebs cycle oxidizes acetyl-CoA in the mitochondria, producing CO2, H2O, NADH2, and FADH2. These molecules carry energy for further ATP production. It is a key step in aerobic respiration for complete glucose oxidation.
6. What is the electron transfer chain reaction, and why is it significant?
Answer: The electron transfer chain reaction uses NADH2 and FADH2 to produce ATP in mitochondria. Each NADH2 generates three ATP, and each FADH2 generates two ATP. This process maximizes energy production from glucose oxidation.
7. How is ATP used as the energy currency of cells?
Answer: ATP stores energy in its phosphate bonds, which can be broken to release energy. Cells use this energy for various functions like movement and growth. ATP is called the energy currency because it powers all cellular activities.
8. What happens in anaerobic respiration, and when does it occur?
Answer: Anaerobic respiration occurs without oxygen, incompletely oxidizing glucose via glycolysis and fermentation. It produces less energy and forms products like lactic acid or alcohol. This happens in organisms like bacteria or muscle cells during intense exercise.
9. How are proteins used for energy in the body?
Answer: Proteins are broken down into amino acids, which are absorbed and used to make body proteins. If carbohydrates are low, amino acids are converted into acetyl-CoA for energy. Excess amino acids are turned into glucose or eliminated as ammonia.
10. What is the role of lipids in the body’s energy and structure?
Answer: Lipids are broken down into fatty acids, which are used to produce energy via the Krebs cycle. They also form phospholipids for cell membranes and hormones like estrogen. Excess lipids are stored in adipose tissue for future energy needs.
11. Why are vitamins essential for body functions?
Answer: Vitamins, like B2 and B3, are needed for processes like producing FADH2 and NADH2 in respiration. They support various body functions, including vision and bone health. A lack of vitamins can cause diseases like night blindness or scurvy.
12. Why is water considered an essential nutrient?
Answer: Water makes up 65-70% of the body and 90% of blood plasma, supporting cell functions. Even a small loss of water can disrupt body processes. It is vital for maintaining health and proper organ operation.
13. How does mitosis help in the growth and repair of the body?
Answer: Mitosis divides somatic cells to produce two identical daughter cells for growth. It helps repair damaged tissues, like healing wounds, by forming new cells. It also supports processes like blood cell formation in the body.
14. What are the main steps of karyokinesis in mitosis?
Answer: Karyokinesis in mitosis includes prophase, metaphase, anaphase, and telophase. In prophase, chromosomes condense; in metaphase, they align at the cell’s center; in anaphase, sister chromatids separate; and in telophase, new nuclei form.
15. How does meiosis differ from mitosis in its process and outcome?
Answer: Meiosis occurs in germ cells and produces four haploid cells through two divisions, including crossing over for genetic diversity. Mitosis occurs in somatic cells, producing two identical diploid cells. Meiosis is essential for gamete and spore formation.
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