G.8 Integrated Science Past Paper 2021-2022 PDF

Hong Kong Baptist University Affiliated School Wong Kam Fai Secondary and Primary School G.8 Integrated Science 2021 – 2022 Self-directed Learning Worksheet Name: ___________________________ Wang Bill...

Hong Kong Baptist University Affiliated School Wong Kam Fai Secondary and Primary School G.8 Integrated Science 2021 – 2022 Self-directed Learning Worksheet Name: ___________________________ Wang Bill ( 33 ) Class: _________ 8E Date: _________________ 30/11/2024 Living Things and Air 7.1 Air (refer to Book 2A p.3–10) ⚫ The layer of air on Earth is called the (1) _______________ Atmosphere. Air is a mixture of gases. It is made up of 78% (2) _________________ Nitrogen , 21% (3) _________________ Oxygen , 0.03% (4) ____________________ Carbon dioxide , 0.9% (5) ____________________ Nobel gases , 0.07% (6) ____________________ Water vapour and other gases. oxygen nitrogen (21%) noble gases (mainly argon) (78%) (0.9%) water vapour and other gases (0.07%) carbon dioxide (0.03%) ⚫ Test for the gases in air: Oxygen It relights a (7) ____________________________ Glowing splint. It causes a (8) ____________________________ Burning splint to burn more brightly. Carbon It turns (9) ________________________________________ Hydrogencarbonate indicator from red to dioxide yellow. It turns (10) __________________________ Lime water from colourless to milky. Water and Both turn dry (11) ____________________________________ Cobalt chloride paper from water vapour blue to pink. Nitrogen and There are no simple tests. They are very unreactive. noble gases -1- ⚫ Daily applications of the gases in air: Oxygen Helps patients with breathing Mixes with gas fuel for cutting difficulties metals Carbon Used in (12) ____________ Fire extinguisher (13) ____________ Dry ice (solid carbon dioxide ____________________ to put dioxide) can produce a fog effect. out fires Nitrogen Used to fill food packages to Liquid nitrogen is used for storing help prevent food from going living cells and tissues. bad Noble gases (14) ___________ Argon (15) ___________ Helium is (16) ___________ Neon is used to fill light used to fill balloons is used to fill bulbs. and airships. advertising lights. -2- Name: ___________________________ Wang Yuhan ( 33 ) Class: _________ 8E Date: _________________ 30/11/2024 7.2 Photosynthesis (refer to Book 2A.10–25) ⚫ Plants can make their own food by (1) __________________________ Photosynthesis. light energy chlorophyll glucose starch water (from the soil) carbon dioxide oxygen (from the air) (given out into the air) Raw (2) _______________________ Carbon dioxide is obtained from the air. materials (3) ________________ Water is absorbed from the soil. Energy Light energy is absorbed by (4) ____________________, Chlorophyll a green source pigment in chloroplasts. Light energy is converted into (5) __________________ Chemical energy in the food produced. Food (6) ________________ Glucose is the food produced. It is used for growth and respiration. Glucose is converted into (7) _______________ Starch for temporary storage if it is not used immediately. They are interconvertible. Both glucose and starch are (8) _____________________. Carbohydrates By-product (9) _______________ Oxygen is produced as a by-product. ⚫ The (10) __________________________ Word equation of the process of photosynthesis: light energy absorbed by chlorophyll carbon dioxide + water glucose + oxygen -3- The (11) __________________________ Chemical equation of the process of photosynthesis: light energy absorbed by chlorophyll 6 CO2 + 6 H2O C6H12O6 + 6 O2 ⚫ The total number of each atom (carbon atom, oxygen atom and hydrogen atom) is (12) ______ Equal __________ on both sides of the equation. ⚫ Test for the products of photosynthesis: 1. Starch We can use (13) ________________________ Iodine solution to test for starch. The solution changes from brown to (14) _________________ Blue-black in the presence of starch. Steps of testing for starch in green leaves and the purpose of each step: Step 1. Put the leaf in boiling water. 2. Put the leaf in hot alcohol. leaf boiling water hot alcohol hot water Purpose: Purpose: To destroy the (15) ____________ Cell membranes To remove (16) ________________ Chloroplasts ___________________ from the leaf 3. Wash the leaf in hot water. 4. Add iodine solution to the leaf. iodine solution hot water Purpose: Purpose: To remove (17) _______________ Alcohol To test for the presence of starch in the and make the leaf soft leaf -4-  2. Oxygen We can use a glowing splint to test for the presence of oxygen. Oxygen can relight a glowing splint. ⚫ To investigate the necessary factors for photosynthesis, we need to (18) ________________ Destarch the plant by placing it in the dark for at least 48 hours. This ensures the plant does not contain any starch when the investigation begins. Any starch detected later is formed during the investigation. ⚫ (19) _____________________, Carbon dioxide (20) _____________________________, Chloroplast (21) ____________ Light and water are necessary for photosynthesis. ⚫ The significance of photosynthesis: providing food for living things maintaining the balance of oxygen and carbon dioxide in Nature ⚫ The (22) ____________________________________ Feeding relationship among living things can be shown by a (23) ______________________. Food chain ⚫ In a food chain, plants are (24) __________________ Producer as they can make their own food. Animals are (25) __________________ Consumer as they feed on plants or other animals. ⚫ (26) ________________ The sun is the ultimate source of energy for all food chains as plants converts light energy into (27) _______________________ Chemical energy which is stored in the food produced. water plant small fish big fish human (producer) (consumer) (consumer) (consumer) ⚫ The energy is transferred from one living thing to another through feeding. ⚫ The arrows in the food chain show the direction of the (28) __________________________. Flow of energy -5- -6- Name: ___________________________ Wang Yuhan ( 33 ) Class: _________ 8E Date: _________________ 30/11/2024 7.3 Respiration (refer to Book 2A p.26–31) ⚫ Food is the source of energy for all living things. ⚫ In our bodies, the chemical energy in food is converted into other useful forms by a process called (1) ___________________. Respiration energy water glucose carbon dioxide (removed from the body oxygen through breathing) (taken into the body through breathing) body cell ⚫ Respiration takes place in our (2) _____________________. Body cells (3) _______________ Glucose is the food broken down in the process. ⚫ The word equation of the process of respiration: energy released glucose + oxygen carbon dioxide + water ⚫ The chemical equation of the process of respiration: energy released C6H12O6 + 6 O2 6 CO2 + 6 H2O ⚫ Comparison between photosynthesis and respiration: Photosynthesis Respiration Raw Carbon dioxide and water Food (glucose) and oxygen materials Products Food (glucose) and oxygen Carbon dioxide and water Where it Takes place only in (4) ____________ Plants Takes place in both (5) ____________ Animals takes place and (6) ______________ Plants When it Takes place under the presence of Takes place (8) ___________________ All the time takes place (7) ______________ Light Energy Energy is stored in food Energy is released from food -7- Name: ___________________________ Wang Yuhan ( 33 ) Class: _________ 8E Date: _________________ 30/11/2024 7.4 Gas exchange in plants and animals (refer to Book 2A p.32–52) ⚫ Photosynthesis and respiration involve the (1) _______________________ Gas exchange in plants and animals. ⚫ Net gas exchange in plants depends on the relative rates of photosynthesis and respiration. ⚫ In the daytime, both photosynthesis and ⚫ At night, photosynthesis stops and only respiration take place. The rate of respiration takes place. photosynthesis is (2) _______________ Higher Net (5) _______________ Release of carbon than the rate of respiration. dioxide Net (3) _______________ Uptake of carbon Net (6) _______________ Uptake of oxygen dioxide Net (4) _______________ Release of oxygen Day Night photosynthesis respiration respiration CO2 in CO2 out CO2 out O2 out O2 in O2 in ⚫ Gas exchange in plants is carried out through (7) _____________ Stomat on the leaf epidermis. ⚫ Each stoma are surrounded by two (8) __________________ Guard cells , which control the opening and closing of the stoma. stoma open stoma closed guard cells (in the daytime) (swollen) guard cells (at night) (shrunken) chloroplast vacuole cell wall stoma nucleus -8- ⚫ The air we breathe in is called inhaled air. The air we breathe out is called exhaled air. They have different compositions. ⚫ Comparison between inhaled air and exhaled air: Inhaled air Exhaled air Oxygen 21% (more) (9) ____________ 16% (less) Carbon dioxide 0.03% (less) (10) ____________ 4% (more) Water vapour variable (less) (11) _____________ Staturated (more) Temperature (12) ____________ Lower (13) ____________ Higher ⚫ Humans have a (14) ___________________________ Breathing system for gas exchange. ⚫ Gas exchange allows a continuous supply of (15) _______________ Oxygen to the body cells for respiration, and removal of (16) ________________________ Carbon dioxide from the body. ⚫ The main parts of the human breathing system: (17) _________________ Nasal cavity (18) _________________ Trachea (23) _________________ Rib (19) _________________ Bronchus (20) _________________ Bronchioles (24) _________________ Lung (21) _________________ Air sacs (25) _________________ Diaphragm (22) _________________ Intercostal muscle ⚫ The pathway of air flowing through the breathing system: nasal air trachea bronchi bronchioles cavity sacs ⚫ Gas exchange takes place at the (26) _______________. Air sacs They are surrounded by many small blood vessels called (27) ______________________. Capillaries -9- ⚫ Gas exchange at the air sacs: (28) ___________________________ Oxygen passes from the air sacs into the blood. (29) ___________________________ Carbon dioxide passes from the blood into the air sacs. ⚫ The airway are lined with (30) ________________________________ Mucus producing cells and (31) _________________________. Ciliated cells Mucus-producing cells produce mucus to trap dust particles and bacteria. Ciliated cells have (32) ____________ Cilia to sweep out dust particles and bacteria trapped in mucus. ⚫ (33) ___________ Tar in cigarette smoke causes cilia to stick together and (34) ______________ Increase mucus production, making the airway narrower and gas exchange more difficult. ⚫ The harmful effects of smoking on our health: Harmful substance Harmful effects on health Causes (35) ____________________ Lung cancer Tar Causes coughs and (36) _____________________ Respiratory disease _________________ Causes (38) ____________________ Addiction (37) _______________________ Nicotine Increases heart rate and blood pressure, leading to (39) ______________________ Heart disease in the long term Reduces oxygen content in blood (40) _______________________ Carbon monoxide The heart needs to beat faster to provide enough oxygen to body cells, leading to heart diseases in the long term -10- Name: ___________________________ Wang Yuhan ( 33 ) Class: _________ 8E Date: _________________ 30/11/2024 7.5 Balance of carbon dioxide and oxygen in Nature (refer to Book 2A p.53–59) ⚫ (1) ____________________ Photosynthesis and (2) ____________________ Respiration are two essential life processes which maintain the (3) ___________________ Balance of carbon dioxide and oxygen in Nature. ⚫ Human activities are disrupting the balance of carbon dioxide and oxygen in Nature, for example, burning (4) ____________________ Fossil fuels and cutting down (5) ______________. Tree ⚫ (6) _____________________________ Greenhouse effect is caused by (7) _____________________ greenhouse gasses _________ that trap heat from the Sun and keep the Earth warm. ⚫ Carbon dioxide is an example of greenhouse gases. The increasing amount of carbon dioxide in the atmosphere enhances greenhouse effect and leads to (8) __________________________ Global warming. ⚫ Possible harmful effects of global warming on the environment: Melting of ice at (9) _________________________ Polar region Average sea levels rise, causing Living things in polar regions such as (10) _______________ Flooding in low-lying areas polar bears may lose their (11) _________________ Habitat (12) ______________________________ Climate change Affecting crop growth and may lead to More frequent (14) _______________, Heat waves (13) ______________________ Food shortage storms and droughts ⚫ To slow down global warming, we should promote (15) __________________________ Low-carbon living to help reduce the emission of carbon dioxide in daily life. -11- 7.6 Air quality (refer to Book 2A p.60–65) ⚫ Burning fossil fuels in power stations, factories and vehicles releases a large amount of (1) _________________________. Air pollutant ⚫ Harmful effects of different air pollutants on our health: Air pollutant Harmful effects on health Reduces oxygen content in blood Carbon monoxide Causes (2) __________________, Headache fainting and even death (3) _______________________ Sulphur dioxide Causes irritation to our breathing system and eyes (4) _______________________ Hydrogen oxide Causes irritation to our breathing system and eyes Cause respiratory disease (e.g. bronchitis and (5) _______________________ Suspended particulate asthma) _____________ Cause (6) ____________________ Lung diseases ⚫ (7) _________________________________________ Fine suspended particulates are particulate matter with a diameter less than or equal to 2.5μm. It is also known as PM2.5. ⚫ The (8) ________________________________________ Air quality health index (AQHI) provides information about air quality. It is based on the measurement at the air quality monitoring stations. The higher the index, the poorer the air quality. ⚫ The AQHI scale: Health risk category AQHI 1–3 4–6 7 8–10 10+ -12- SUGGESTED ANSWERS 7.1 (1) atmosphere (2) nitrogen (3) oxygen (4) carbon dioxide (5) noble gases (6) water vapour (7) burning splint (8) glowing splint hydrogencarbonate cobalt chloride (9) (10) limewater (11) (12) fire extinguishers indicator paper (13) Dry ice (14) Argon (15) Helium (16) Neon 7.2 (1) photosynthesis (2) Carbon dioxide (3) Water (4) chlorophyll (5) chemical (6) Glucose (7) starch (8) carbohydrates chemical (9) Oxygen (10) word equation (11) (12) the same equation (13) iodine solution (14) blue-black (15) cell membrane (16) chlorophyll (17) alcohol (18) destarch (19) chlorophyll* (20) carbon dioxide* feeding (21) light* (22) (23) food chain (24) producers relationship (25) consumers (26) The Sun (27) chemical energy (28) flow of energy 7.3 (1) respiration (2) body cells (3) Glucose (4) plants (5) animals* (6) plants* (7) light (8) all the time 7.4 (1) gas exchange (2) higher (3) uptake (4) release (5) release (6) uptake (7) stomata (8) guard cells (9) 16% (10) 4% (11) saturated (12) lower breathing (13) higher (14) (15) oxygen (16) carbon dioxide system (17) nasal cavity (18) trachea (19) bronchus (20) bronchiole intercostal (21) air sac (22) (23) rib (24) lung muscle (25) diaphragm (26) air sacs (27) capillaries (28) Oxygen mucus-producing (29) Carbon dioxide (30) (31) ciliated cells (32) cilia cells respiratory (33) Tar (34) increases (35) lung cancer (36) diseases carbon (37) Nicotine (38) addiction (39) heart diseases (40) monoxide 7.5 (1) Photosynthesis* (2) respiration* (3) balance (4) fossil fuels Greenhouse greenhouse (5) trees (6) (7) (8) global warming effect gases (9) polar regions (10) flooding (11) habitat (12) climate change (13) food shortages (14) heat waves (15) low-carbon living 7.6 (1) air pollutants (2) headaches (3) Sulphur dioxide (4) Nitrogen oxides Suspended Fine suspended Air Quality (5) (6) lung diseases (7) (8) particulates particulates Health Index (Note: Accept answers marked with * in different orders) -13-