Integrated Science 1st Secondary Past Paper PDF

First Term Sec (1) Mr / Mohamed Abdallah 1 01006725680  First Term Sec (1) Remember: In the world of aquatic creatures, every organism has a set of adaptations that help it to survive in its...

First Term Sec (1) Mr / Mohamed Abdallah 1 01006725680  First Term Sec (1) Remember: In the world of aquatic creatures, every organism has a set of adaptations that help it to survive in its environment, whether it is a deep ocean or a shallow lake. In this lesson, we will explore these physiological, behavioral, and structural adaptations that allow aquatic organisms to survive under different environmental conditions. Physiological (functional) adaptation: Adaptations or modifications in the way they perform their biological/vital functions. 1. Some deep-ocean fish have special abilities to regulate respiration under the state of oxygen deficiency. To adapt to the high-water pressure at great depths, deep-sea fish have strong and durable arteries and veins that can withstand he high pressure. They also have the ability to effectively adjust their blood pressure to equalize the external pressure. 2. The Electric Eel, which lives at depths of thousands of meters, where oxygen levels are extremely low. These fish have developed very large gills, with very fine capillaries that maximize the efficiency of extracting the little oxygen found in water. In addition, they can slow down their metabolism to minimize their oxygen needs. Osmosis and osmotic pressure: Mr / Mohamed Abdallah 2 01006725680  First Term Sec (1)  Osmosis is the phenomenon of water transfer from a dilute solution to a concentrated solution through a semi-permeable membrane separating the two solutions.  Osmotic pressure is the pressure created in a solution due to the difference in solute concentration in the solution and leads to the diffusion of water from the less concentrated solution (low osmotic pressure) towards the more concentrated solution (higher osmotic pressure).  Practical activity:  Tools: Sugar solution-Thistle funnel-Cellophane paper-Glass beaker half- filled with tap water-Rubber band–Stand.  Steps: 1. Tightly fix the cellophane paper to the opening of the funnel with the rubber band. 2. Fill the funnel with the sugar solution, submerge it in the water-filled beaker and hold it vertically. 3. Mark the solution level in the stem of the funnel Leave the device for a sufficient period of time.  Observations: the solution level in the funnel stem increases as it draws water from the beaker by osmosis, since the sugar concentration in the funnel is higher than its concentration in the beaker.  The previous experiment showed what could happen to an organism living in freshwater when the osmotic pressure of the water is lower than the osmotic pressure of their bodies.  In this case, the bodies of these organisms will draw large amounts of water, causing them to burst and die. So, how do these organisms adapt to the characteristics of the freshwater environment?  Unicellular organisms, such as amoeba, paramecium, and euglena, have a structure or an organelle called a contractile vacuole that collects excess water in the cell and when it is filled with water, it moves towards the cell membrane where it discharges its water content to the outside of the cell. Mr / Mohamed Abdallah 3 01006725680  First Term Sec (1)  Multicellular organisms, such as fish, eliminate excess water that enters the body through the skin, mouth, and gills by the kidneys in the form of dilute urine. In fish, the kidneys are located in the abdominal cavity on either side of the spine.  While fish that live in saltwater need to swallow large amounts of sea water to compensate for the osmotic loss of water from their body, and then they excrete excess salts through their kidneys and specialized cells in their gills.  As a physiological adaptation to the high salinity of the ocean and sea water, sharks maintain the balance of water and salts within their bodies through controlling the level of urea in their blood. Urea is a nitrogenous compound that is excreted in the urine of many animals to get rid of it. Sharks keep a high concentration of urea in their blood, which increases their osmotic pressure, bringing it close to the osmotic pressure of the surrounding water. This helps minimize the loss of water from their body to the surrounding environment of high salinity.  Behavioral adaptations include certain actions or behaviors that organisms use to avoid extreme conditions or to better utilize available resources. 1. Some fish migrate between fresh and salt water to reproduce and survive. 2. Salmon are born in freshwater, then move to the sea where they spend most of their adult life, before returning to rivers again to reproduce.  When salmon eggs hatch, their young spend the first period of their lives in freshwater. During this stage, the youngsters adapt to the freshwater environment. Upon reaching a certain size, the fish undergo a biological process known as “Smoltification” which allows them to move to the saltwater of the sea. When salmon reach sexual maturity, they begin to return to the rivers where they were born to reproduce. Mr / Mohamed Abdallah 4 01006725680  First Term Sec (1)  The ability of salmon to move between different environments is due to their ability to make complex physiological adaptations. For example, their circulatory and respiratory systems adapt to changes in salinity and different amounts of oxygen in fresh and salt water.  Structural adaptations include changes in the physical structure of organisms that help them survive in their environments. 1. Fish that live in the deep ocean have very large eyes to be able to see in the dark, and their bodies are compressed to withstand the very high pressure in deep water.  An example of a compressed deep-sea fish is the ice fish, which lives in the cold southern oceans, at depths of about 2000 meters. 2. Among the general structural adaptations of fish are a streamlined body that reduces water resistance to the fish's movement, gills that enable it to extract dissolved oxygen in water, and its body is covered with scales and mucus to be waterproof and to reduce water resistance to its movement, fins are movement organs, and bony fish have an air bladder or swim bladder that helps them float in the water.  Gas exchange is when an organism obtains oxygen from atmospheric air or the surrounding environment and removes carbon dioxide. Cellular respiration is a vital process in which the organism breaks down the bonds in food molecules, especially glucose, to obtain stored energy. Unicellular organisms, such as amoeba obtain oxygen and eliminate carbon dioxide through the cell membrane by diffusion. Mr / Mohamed Abdallah 5 01006725680 First Term Sec (1) Lecture 4 Exercises: Biological adaptations of organisms in the aquatic environment Choose the correct answer from the given options: 1. What are the physiological adaptations of fish that live in the depths of the oceans? a) Small gills b) Strong blood vessels c) Increased metabolic rate d) Inability to regulate blood pressure 2. How do large gills and capillaries help deep-sea fish? a) Increase the amount of oxygen extracted from water b) Reduce the need for oxygen c) Improve movement ability d) Raise pressure in the body 3. What is an example of a fish that lives in the depths of the ocean and adapts to low oxygen levels? a) Shark b) Electric eel c) Salmon d) Tuna 4. How does osmosis affect the movement of water between solutions? a) Water moves from a concentrated solution to a diluted one b) Water moves from a diluted solution to a concentrated one c) Water moves evenly between the solutions d) Osmosis does not affect water movement 5. What leads to an increase in osmotic pressure? a) Increase in concentration of the diluted solution b) Concentration difference between the solutions c) Decrease in concentration of the concentrated solution d) Decrease in concentration difference 6. How can fish living in low-oxygen environments reduce their oxygen needs? a) Increase metabolic rate b) Decrease metabolic rate c) Increase food consumption d) Reduce gill size Mr / Mohamed Abdallah 6 01006725680 First Term Sec (1) 7. What is the semipermeable membrane in the process of osmosis? a) Allows all substances to pass b) Allows only water to pass c) Allows only the concentrated solution to pass d) Prevents any substance from passing 8. How does osmotic pressure affect water movement? a) Increases the flow of water to the less concentrated solution b) Increases the flow of water to the more concentrated solution c) Prevents water movement d) Makes water move in equal directions 9. How do strong blood vessels help deep-sea fish? a) Improve their breathing ability b) Help them adapt to high pressure c) Increase oxygen consumption d) Decrease carbon dioxide levels 10. Why are deep-sea fish capable of adjusting their blood pressure? a) To reduce oxygen consumption b) To adapt to high pressure in the depths c) To improve digestion d) To enhance their photosynthetic ability 11. What is the osmotic pressure of freshwater compared to the bodies of living organisms? a) Higher b) Lower c) Equal d) Irrelevant 12. What happens to the bodies of living organisms in freshwater due to decreased osmotic pressure? a) They shrink b) They burst c) They remain stable d) They freeze 13. What organ do unicellular organisms have to adapt to freshwater? a) Kidneys b) Contractile vacuole c) Gills d) Lungs Mr / Mohamed Abdallah 7 01006725680 First Term Sec (1) 14. How does the contractile vacuole work in unicellular organisms? a) Collects excess water and pushes it out of the cell b) Absorbs food c) Stores energy d) Conducts respiration 15. How do fish eliminate excess water from their bodies? a) Through the skin only b) Through kidneys, mouth, and gills c) Through breathing d) Through contractile vacuoles 16. Where are the kidneys located in fish? a) In the head b) In the abdominal cavity on either side of the spine c) In the tail d) In the gills 17. How do fish that live in saline environments adapt to high salinity levels? a) Absorb water through their skin b) Ingest large amounts of water and excrete excess salts c) Do nothing d) Avoid saline water 18. What is the source of water that saltwater fish need to compensate for water loss? a) Freshwater b) Highly saline seawater c) Rainwater d) Distilled water 19. How do sharks maintain water and salt balance in their bodies? a) By consuming large amounts of food b) By controlling the urea levels in their blood c) By continuous urination d) By absorbing water through their skin 20. What is the effect of urea concentration in shark blood on osmotic pressure? a) Decreases osmotic pressure b) Increases osmotic pressure c) No effect d) Causes cell bursting Mr / Mohamed Abdallah 8 01006725680 First Term Sec (1) 21. How does high osmotic urea pressure help reduce water loss? a) Absorbs water from the environment b) Causes water pressure balance between the body and the surrounding environment c) Increases metabolic rate d) Makes fish avoid saline water 22. What is the consequence of an organism's inability to adapt to decreased osmotic pressure in freshwater? a) Lives longer b) Easily adapts c) Dies due to cell bursting d) Migrates to other environments 23. What is the role of gills in saltwater fish? a) No role b) Helps absorb water c) Excretes excess salts d) Only contributes to respiration 24. How do multicellular organisms adapt to freshwater? a) By reducing their size b) By developing kidneys to eliminate excess water c) By using contractile vacuoles d) By increasing food intake 25. What is the effect of the saline environment on fish in forming their osmotic pressure? a) Increases oxygen needs b) Decreases adaptation level c) Requires them to adjust osmotic pressure to cope with the environment d) Has no effect on fish 26. What are behavioral adaptations? a) Behaviors or actions taken by living organisms to avoid harsh conditions b) Changes in the genetic structure of organisms c) Changes in the surrounding environment d) Photosynthesis processes 27. What is the reason for some fish migrating between freshwater and saltwater? a) Only to search for food b) For reproduction and survival c) To avoid predators d) For seasonal migration Mr / Mohamed Abdallah 9 01006725680 First Term Sec (1) 28. Where is salmon born? a) In the sea b) In saltwater c) In freshwater d) In glacial rivers 29. What happens to salmon after spending most of their lives in the sea? a) They die b) They migrate to the ocean c) They return to rivers to spawn d) They stay in the sea 30. When do young salmon undergo osmotic adaptation? a) When they reach sexual maturity b) At birth c) When they reach a certain size d) Before hatching 31. What is the process that allows salmon to transition to saltwater? a) Osmotic adaptation (Smoltification) b) Thermal adaptation c) Nutritional adaptation d) Seasonal migration 32. How does the salmon cycle adapt to different environments? a) By increasing heart rate b) By changing skin color c) By adapting to changes in salinity and oxygen levels d) By reducing body size 33. What is the first stage of young salmon life? a) Living in the sea b) Living in freshwater c) Spawning d) Transitioning to the ocean 34. What is the main benefit of salmon's ability to move between different environments? a) Improved swimming ability b) Increased adaptability to changing conditions c) Reduced extinction risk d) Increased genetic diversity Mr / Mohamed Abdallah 10 01006725680 First Term Sec (1) 35. How does salinity affect salmon's ability to live in different environments? a) Affects only metabolic rate b) Requires complex physiological adaptations c) Has no effect d) Makes salmon more susceptible to diseases 36. What are structural adaptations? a) Changes in behavior b) Changes in the physical structure of living organisms c) Changes in diet d) Changes in social behavior 37. How do large eyes help fish living in the depths of the oceans? a) Swim faster b) See in the dark c) Breathe underwater d) Reduce water resistance 38. What body shape helps compressed fish withstand high pressure in the depths? a) Rounded body shape b) Flat body shape c) Compressed body shape d) Elongated body shape 39. What is the function of gills in fish? a) Assist in movement b) Used for buoyancy c) Enable extraction of dissolved oxygen from water d) Assist in excretion 40. How does a body covered in scales and mucus help fish? a) Increases body size b) Reduces water resistance when swimming c) Makes them less attractive to predators d) Improves their photosynthetic ability 41. What is gas exchange? a) The process of food production b) The acquisition of oxygen and the removal of carbon dioxide by an organism c) The process of protein formation d) The process of storage in the body Mr / Mohamed Abdallah 11 01006725680 First Term Sec (1) 42. What is cellular respiration? a) Breaking bonds in food molecules to obtain energy b) Gas exchange between living organisms c) Absorbing nutrients from the soil d) Excreting waste from the body 43. How do unicellular organisms like amoebas obtain oxygen? a) By consuming food b) Through the cell membrane by diffusion c) Through pulmonary respiration d) Through capillaries 44. What is the primary molecule broken down in cellular respiration to obtain energy? a) Fats b) Proteins c) Glucose d) Nucleic acids 45. What is the primary outcome of cellular respiration? a) Oxygen production b) Energy acquisition c) Weight gain d) Cell size reduction 46. Which of the following adaptations allows deep-sea fish to coexist with low oxygen levels? a) Slowing metabolic rate b) Compressed body c) Increased salt concentration in cells d) Strong blood vessels 47. What type of osmotic adaptation do salmon exhibit? a) Behavioral adaptation b) Physiological adaptation c) Structural adaptation d) Physiological and structural adaptation 48. Which of the following is a similarity between amoebas and fish? a) Cellular respiration b) Gas exchange organ c) Body complexity d) Osmotic regulation methods 49. Which of the following helps reduce water resistance for fish movement in water? a) Scales only b) Mucus only c) Mucus and streamlined body d) Streamlined body, mucus, and scales Mr / Mohamed Abdallah 12 01006725680