Life Sciences Grade 10 Revision Material Term 2 2024 PDF

Western Cape Education Department Directorate: Curriculum FET LIFE SCIENCES REVISION BOOKLET 2024 TERM 2 Grade 10 This revision program is designed to assist you in revising the cri...

Western Cape Education Department Directorate: Curriculum FET LIFE SCIENCES REVISION BOOKLET 2024 TERM 2 Grade 10 This revision program is designed to assist you in revising the critical content and skills that you have covered during the 2nd term. The purpose is to prepare you to understand the key concepts and to provide you with an opportunity to establish the required standard and the application of the knowledge necessary to succeed in the examination. The revision program covers the following topics: Animal tissues Plant tisues Organs Support and transport systems in plants Support systems in animals Transport systems in animals  2 Life Sciences revision booklet 2024 Grade 10 Term 2 Table of Contents TERM 2 CONTENT...................................................................................................................................... 3 1. ANIMAL TISSUES................................................................................................................................ 3 2. PLANT TISSUES................................................................................................................................... 6 3. ORGANS............................................................................................................................................. 8 4. SUPPORT AND TRANSPORT SYSTEMS IN PLANTS.............................................................................. 9 5. SUPPORT SYSTEMS IN ANIMALS...................................................................................................... 13 6. TRANSPORT SYSTEMS IN ANIMALS.................................................................................................. 16 7. REVISION QUESTIONS:..................................................................................................................... 21  3 Life Sciences revision booklet 2024 Grade 10 Term 2 TERM 2 CONTENT 1. ANIMAL TISSUES Tissues are a group of similar cells that are structurally adapted to perform a particular function. Cells are adapted for specific functions through a process of cell differentiation. Examples of animal tissues are epithelial tissue, connective tissue, muscle tissue and nerve tissue. Tissue group Type of tissue Structure Function/s Illustration Squamous Single layer of Protects underlying (lines internal thin, flat cells. tissues. It is walls of cavities Nucleus permeable to i.e. blood vessels,horizontally gasses and liquids. heart, alveoli, flattened and It prevents friction mouth and has an oval esophagus) shape Columnar Cells are Provides support to (lines the elongated and other cell types. alimentary canal column-shaped. Absorbs food, e.g. stomach and Nuclei are water and small intestine) elongated and minerals. Goblet occurs near the cells secrete base of the mucus cells. Goblet Epithelial cells which tissue secrete mucus (form linings often occur that cover between the internal and cells external Ciliated Consists of Mucus from goblet surfaces) (lines the nasal columnar cells traps dust and cavities, trachea epithelial cells movement of the and bronchi in with fine hairs, cilia away from the the lungs) known as cilia. lungs will ensure Goblet cells that mucus is which secrete removed. mucus often occur between the cells Cuboidal Cells are more Produce a variety (lines glands e.g. or less cube- of secretions e.g. sweat glands and shaped. Nuclei sweat, milk etc. salivary glands are round and where it secretes occur in the substances) centre of the cell.  4 Life Sciences revision booklet 2024 Grade 10 Term 2 Tissue group Type of tissue Structure Function/s Illustration Areolar Yellow, elastic Insulates the body. connective tissue fibres and white, Protect organs by (forms a layer inelastic serving as packing beneath the skin collagen fibres tissue and connects the are found in the skin to underlying matrix of this muscles) tissue Dense Consists of a Inelastic tendons connective tissue small amount of join muscle to (joins muscle to matrix, large bone. bone and bone number of fibres Elastic ligaments to bone) and a small join bone to bone number of cells Cartilage Rubbery matrix Reduces friction (tough, elastic that consists of between bones at tissue that forms a protein called, joints part of the chondrin. endoskeleton of Cartilage cells, vertebrates) called chondrocytes, occur in spaces (lacunae) in the Connective matrix. tissue Cartilage is (binds, protected by a supports or membrane, the surrounds perichondrium other tissues Bone Contains a hard Bone is a or organs) (occurs in the matrix. supporting various bones of Haversian framework that the endoskeleton canals that gives shape and of vertebrates) contain blood rigidity to the vessels and body. It protects nerves occur in organs e.g. the bone tissue. brain, heart and Bone cells are lungs. It serves as called place of osteocytes. attachment for Bone is muscles enclosed by a membrane, the periosteum Blood Matrix of blood Transports (Circulates in is known as nutrients, blood vessels) blood plasma. hormones, Three types of enzymes, oxygen, blood cells in carbon dioxide the blood and waste  5 Life Sciences revision booklet 2024 Grade 10 Term 2 Tissue group Type of tissue Structure Function/s Illustration plasma i.e. products in the erythrocytes, body. Plays a role leucocytes and in blood-clotting. thrombocytes Striated/Skeletal Consists of Responsible for muscle muscle voluntary actions (Attached to fibres/cells. A such as walking bone and muscle fibre and running responsible for consists of movement of the cytoplasm, skeleton) large number of nuclei and mitochondria which is enclosed by a membrane called the sarcolemma. Muscle tissue Each muscle (responsible fibre consists of for thousands of movement in myofibrils different Smooth muscle Consists of Responsible for parts of the (Found in the spindle-shaped involuntary actions body) walls of the muscle fibres e.g. dilation and alimentary canal, with one large constriction of bladder, blood oval nucleus per blood vessels vessels and fibre uterus) Cardiac muscle Consists of Responsible for (Occurs in the branched involuntary walls of the heart) muscle fibres contraction and that are relaxation of the connected to heart one another. A single nucleus is in the centre of each fibre. Nerve tissue Motor neurons A neuron Conduct nerve (Made up of consists of a cell impulses from the specialized body, dendrites central nervous cells called and an axon. system (brain and neurons. Dendrites spinal cord) to the Nerve tissue conduct nerve effectors (muscles that forms the impulses to the and glands) brain and cell body. An spinal cord is axon conducts  6 Life Sciences revision booklet 2024 Grade 10 Term 2 Tissue group Type of tissue Structure Function/s Illustration known as the Sensory neurons nerve impulses Conduct nerve central away from the impulses from the nervous cell body receptors (e.g. system. Nerve sensory organs) to tissue outside the central the central nervous system nervous (brain and spinal system is cord) known as the peripheral Interneurons Conduct nerve nervous impulses between system.) the sensory and motor neurons in the brain and spinal cord 2. PLANT TISSUES Plant tissues can be divided into meristematic tissue and permanent tissue. Meristematic tissue is actively dividing tissue in which new cells are formed by mitosis. The cells are not differentiated to perform a specific function. Permanent tissue is already differentiated to perform a specific function and includes xylem, phloem, parenchyma, collenchyma, sclerenchyma and epidermis. 2.1 Meristematic tissue Apical meristem is found near the tips of roots and stems and are responsible for growth in length. Lateral meristem is found between the xylem and phloem in a dicotelydonous plant, and it makes the plant grows thicker. 2.2 Permanent tissue Type of tissue Structure Function/s Illustration Epidermis Forms the Protects the outer layer underlying tissues around roots, from injury. stems and Cuticle prevents leaves. water-loss in Brick-shaped leaves and stems. and in a Transparent single layer epidermis allows Cells are sunlight through transparent for with no photosynthesis. intercellular air spaces.  7 Life Sciences revision booklet 2024 Grade 10 Term 2 Type of tissue Structure Function/s Illustration Epidermis of leaves and stems are covered with a waxy layer, the cuticle. Specialised epidermal cells are root hairs and guard cells. Parenchyma Large with Stores food and thin cell walls water Large Produces intercellular carbohydrates spaces through Large photosynthesis vacuoles Intercellular Cells contain spaces allow for chloroplasts gaseous in leaves and exchange stems Sclerenchyma Cells are Provides the dead and plant with hollow structure and Contain lignin support Two types i.e. sclereids and fibres Collenchyma Unevenly Provides thickened mechanical cells with support to the cellulose plant Most thickenings occur in the corners of the cell walls Xylem Cells are Transport water elongated and mineral salts Contains no from the roots to living material the rest of the Cell walls plant thickened by Serves as lignin strengthening Consists of and support xylem vessels tissue and tracheids  8 Life Sciences revision booklet 2024 Grade 10 Term 2 Type of tissue Structure Function/s Illustration Phloem Living, Transport organic elongated substances from cells without the leaves to the thickened rest of the plant walls Consists of sieve tubes and companion cells 3. ORGANS An organ is a group of tissues that perform a specific function. 3.1 Leaf structure Leaf section Structure Functions Epidermis Covers upper and lower Protects the underlying surfaces of the leaf. tissues. Transparent and do not Cuticle reduces excessive contain chloroplasts. moisture loss. Waxy cuticle covers the Allow light through for epidermis. Lower photosynthesis. epidermal cells contain Stomata are responsible stomata for gaseous exchange into and out of leaf Mesophyll Palisade cells: elongated Palisade cells are primarily (Palisade and spongy cells under the upper responsible for mesophyll) epidermis. Contain large photosynthesis amount of chloroplasts. No intercellular air spaces between the cells. Cell walls are thin. Spongy cells: round Spongy cells are also parenchyma cells with responsible for large intercellular air  9 Life Sciences revision booklet 2024 Grade 10 Term 2 Leaf section Structure Functions spaces. Contain photosynthesis and chloroplasts. gaseous exchange Vascular bundles Xylem and phloem Xylem transports water and dissolved mineral salts to the mesophyll cells Phloem transports produced organic nutrients to other parts of the plant. 4. SUPPORT AND TRANSPORT SYSTEMS IN PLANTS 4.1 ANATOMY OF DICOTELYDONOUS PLANTS 4.1.1 Internal structure of a root When the cross section of a young dicotyledonous root (refer to diagram below) is studied, three regions can be distinguished i.e. the epidermis, cortex and the central cylinder: The epidermis forms the outer layer of the root and contain finger-like outgrowths, the root hairs. The cortex consists of parenchyma cells with large intercellular air spaces. The inner-most layer of the cortex consists of a single layer of cells called the endodermis. The radial and transverse walls of the endodermis contain thickened strips known as the Casparian strips The central cylinder: under the epidermis there are thin-walled cells called the pericycle. On the inside of the pericycle is the vascular tissue that consists of xylem and phloem.  10 Life Sciences revision booklet 2024 Grade 10 Term 2 4.1.2 Internal structure of a stem: When the cross section of a young dicotyledonous stem (refer to diagram below) is studied, three regions can be distinguished i.e. the epidermis, cortex and the central cylinder: The epidermis forms the outer layer of the stem. The cortex consists of collenchyma, parenchyma and endodermis. The central cylinder: Xylem and phloem occur in vascular bundles in the stem. The xylem is on the inside and the phloem on the outside. A layer of meristematic tissue, the cambium, occurs between the xylem and phloem. Cambium makes secondary thickening possible. The central region of the stem is the pith and consists of parenchyma cells. 4.1.3 Uptake of water and mineral salts by the roots:  11 Life Sciences revision booklet 2024 Grade 10 Term 2 The water potential of the soil water is higher (contains less dissolved substances) than the water potential of the cell sap in the vacuoles of the root hair Water molecules move by osmosis through the permeable cell wall, through the selectively permeable cell membrane, cytoplasm and selectively permeable tonoplast into the vacuole of the root hair. The vacuole swells and the pressure within the root hair increases. The pressure that builds up in the vacuole is called, turgor pressure. 4.1.4 Movement of water from the root hair to the xylem of the root: The water potential in the root hair is now higher than in the adjacent parenchyma cells in the cortex of the root. Water moves in two ways to the xylem of the root: The main route that water takes is from cell to cell by osmosis – this is a slow process Water can also move through the cell walls and intercellular air spaces between the cells by diffusion – this is a faster process When water reaches the endodermis, with Casparian strips, it cannot pass through the cell walls of these cells. Water now moves through the passage cells of the endodermis through the pericycle to the root xylem.  12 Life Sciences revision booklet 2024 Grade 10 Term 2 4.1.5 Upward movement of water from the xylem of the root to the leaves of the plant: Revise the cross-section through the leaf. The three forces involved in the upward movement of water in a plant is: capillarity, root pressure and transpiration pull. Refer to the list of definitions and textbook and study the sections on capillarity and root pressure. Transpiration pull is the main force that draws water upwards in a plant. The water potential in the intercellular air spaces of the mesophyll cells decreases as water vapour is lost through the stomata of the leaves. Water molecules diffuse from the cell walls of the mesophyll cells into the air spaces The water potential of the mesophyll cell walls is now lower than that of the cell sap of the mesophyll cells This water potential gradient extends back to the leaf xylem. Tension builds up and a suction force develops at the top of the stem xylem, which pulls water up from the root xylem. A column of water is pulled upwards. Therefore, the water that was lost through the leaves by transpiration is replaced by the absorbed water from the soil through the root hairs. 4.1.6 The translocation of manufactured food from the leaves to other parts of the plant: Translocation is the movement of substances e.g. sugars (sucrose) that are produced in the leaves during photosynthesis to other part of the plant. These substances are transported by the phloem from the leaves to the stems and the roots. 4.1.7. TRANSPIRATION: Transpiration is the loss of water vapour through the aerial parts of the plant mainly through the stomata. 4.1.7.1 Relationship between water loss and the structure of a leaf: The smaller the leaves, the smaller the surface area for evaporation. Thorns and hairs on a leaf limit transpiration. Leaves with stomata mainly on the lower side of the leaf or leaves with sunken stomata will limit transpiration.  13 Life Sciences revision booklet 2024 Grade 10 Term 2 4.1.7.2 External factors influencing transpiration: High temperatures increase the rate of transpiration. Higher light intensity will increase the rate of transpiration. High humidity will decrease the rate of transpiration. Wind will increase the rate of transpiration. 5. SUPPORT SYSTEMS IN ANIMALS 5.1 The human skeleton The human skeleton can be divided into two main sections: Axial skeleton Appendicular skeleton  14 Life Sciences revision booklet 2024 Grade 10 Term 2 The axial skeleton consists of the skull, vertebral column and rib cage: 5.1.1 The skull The skull consists of two groups of bones, namely the bones of the cranium and the facial bones. The cranium encloses the brain and protects it. The cranium of apes is smaller than that of humans. (links with Human Evolution in Grade 12). There is a large opening at the base of the skull called the foramen magnum for the spinal cord to pass through. (links with Human Evolution in Grade 12). In humans the foramen magnum is located in a more forward position, and this enables humans to walk on two legs, a characteristic called bipedalism. (links with Human Evolution in Grade 12). In African apes the foramen magnum is located in a more backward position. Apes generally use all four limbs for locomotion, and they are quadrupedal. (links with Human Evolution in Grade 12). The upper jaw of humans is fused to the skull and the lower jaw articulates with the base of the skull. The jaws of the human are smaller than that of apes. (links with Human Evolution in Grade 12). The palate in humans is rounded whilst the palate in for example chimpanzees is rectangular. (links with Human Evolution in Grade 12). The upper and lower jaws carry the teeth in humans. Humans have smaller teeth than apes. (links with Human Evolution in Grade 12). Humans have four types of teeth with different functions: Type of teeth Function Incisors Bite and cut off food Canines Hold food in place and tear it off Premolars Chew and grind the food Molars Chew and grind the food The human dental formula is: 2.1.2.3 2.1.2.3 5.1.2 Vertebral column The vertebral column of humans consists of 33 bones (vertebrae). The first cervical vertebra articulates with the skull and is known as the atlas. This makes nodding movements possible.  15 Life Sciences revision booklet 2024 Grade 10 Term 2 The second cervical vertebra is called the axis and makes the rotation of the head possible. The human vertebral column is S-shaped for flexibility and shock absorption. (links with Human Evolution in Grade 12). The vertebral column in apes is C-shaped (links with Human Evolution in Grade 12). The vertebral column supports the skull It surrounds and protects the spinal cord. It serves as attachment for the ribs, back muscles, pectoral and pelvic girdle. 5.1.3 Rib cage The rib cage consists of 12 thoracic vertebrae, 12 pairs of ribs and the sternum. The rib cage protects the organs in the thoracic cavity e.g. heart and lungs. It plays a role in breathing as the movement of the rib cage increases and decreases the volume of the thoracic cavity (links with Gaseous exchange in Grade 11). 5.1.4 Appendicular skeleton The appendicular skeleton consists of the pectoral girdle, upper limbs, pelvic girdle and lower limbs. The pectoral girdle consists of the 2 scapulae and 2 clavicles. Each upper limb consists of different kind of bones i.e. the humerus (long bone), ulna (largest bone in the forearm), radius, carpals, metacarpals (bones that form the palm of the hand) and phalanges (bones that form the fingers). The pelvic girdle consists of 2 hip bones. The hip bones are made up of 3 fused bones i.e. the ilium, ischium and the pubis. The hip bones are attached at the back by the sacrum. The human pelvic girdle is shorter and wider to support the greater weight due to the upright posture of humans. Apes have a long and narrow pelvic girdle. (links with Human Evolution in Grade 12). Each lower limb consists of the femur (longest and largest bone in the human body), the patella (kneecap), tibia, fibula, tarsals, metatarsals and the phalanges (toe bones). Humans have shorter arms and longer legs while apes have shorter legs and longer arms. (links with Human Evolution in Grade 12).  16 Life Sciences revision booklet 2024 Grade 10 Term 2 5.1.5 Functions of the skeleton Support – bones of the skeletal system support and give shape to the body and attach muscles and soft organs. Movement – the skeleton plays a role in movement together with the muscles and joints. Protection – Bones protect soft delicate organs e.g. the brain, the heart and lungs. Mineral storage – bone tissue stores reserve calcium and phosphorous. Hearing – three ear ossicles in each ear transmit sound waves to the internal ear to make hearing possible (links with the ear in Grade 12). Production of blood cells – white and red blood cells are formed in the red bone marrow. 6. TRANSPORT SYSTEMS IN ANIMALS 6.1 Blood circulatory system 6.1.1 Closed, double circulatory system: Humans have a closed, double circulatory system. It is closed because blood is limited to the blood vessels. It is a double system because blood flows through the heart twice i.e. once when the blood is oxygenated and a second time when the blood is deoxygenated. Two main circulatory systems can be distinguished, the pulmonary circulatory system and the systemic circulatory system. The pulmonary circulatory system is the circulation of blood from the heart to the lungs and back. The systemic circulatory system is the circulation of blood to all parts of the body. Double, circulatory system  17 Life Sciences revision booklet 2024 Grade 10 Term 2 6.1.2 Structure of the human heart 6.1.2.1 External structure The human heart is a hollow, pear shaped and muscular organ. The heart is situated in the thoracic cavity and is protected by the ribs and sternum. The heart is enclosed by a double walled membrane called the pericardium. 6.1.2.2 Internal structure The heart is divided internally into a left and right half by a muscular wall, the septum. The left side contains oxygenated blood (high concentration of oxygen) and the right side contains deoxygenated blood (low concentration of oxygen). The heart consists of four chambers. The upper 2 chambers are called atria and the lower chambers are the ventricles. 6.1.2.3 Right side of the heart The right atrium receives deoxygenated blood from the whole body. The vena cava superior transports deoxygenated blood from the head and arms to the heart. The vena cava inferior transports deoxygenated blood from the lower limbs and abdomen to the heart. The right ventricle receives blood from the right atrium through an opening. Deoxygenated blood is then pumped to the lungs via the pulmonary arteries. 6.1.2.4 Left side of the heart The left atrium receives oxygenated blood from the lungs. Four pulmonary veins transport the oxygenated blood to the heart. The left ventricle receives oxygenated blood from the left atrium.  18 Life Sciences revision booklet 2024 Grade 10 Term 2 The oxygenated blood is then pumped through the aorta to the rest of the body. 6.1.2.5 Valves The tricuspid valve is situated in the opening between the right atrium and right ventricle. The valve consists of three flaps and the flaps are attached to the inner walls of the right ventricle by tendons, the chordae tendineae. This valve only allows blood to flow from the right atrium to the right ventricle. The bicuspid valve (mitral valve) is situated in the opening between the left atrium and left ventricle. The valve consists of two flaps and the flaps are attached to the inner walls of the left ventricle by tendons, the chordae tendineae. This valve only allows blood to flow from the left atrium to the left ventricle. The semilunar valves occur at the base of the aorta and pulmonary artery. These valves prevent blood from flowing back into the ventricles. 6.2 The cardiac cycle The human heart beats an average of 72 beats per minute. All the changes that occur in the heart during one heartbeat are known as the cardiac cycle. The cardiac cycle can be divided into 3 phases i.e. atrial systole, ventricular systole and general diastole. 6.2.1 Atrial systole Both atria are filled with blood and contract simultaneously. The openings of the vena cavae and pulmonary veins are closed. The tricuspid and bicuspid valves open and the blood is pumped to the ventricles. 6.2.2 Ventricular systole The ventricles contract simultaneously. The tricuspid and bicuspid valves close. Deoxygenated blood is pumped out of the right ventricle into the pulmonary artery Oxygenated blood is pumped from the left ventricle into the aorta. 6.2.3 General diastole Both the ventricles and atria are relaxed. Deoxygenated blood flows from the two vena cavae into the right atrium Oxygenated blood flows from the four pulmonary veins in the left atrium. Blood in the atria flows to the ventricles.  19 Life Sciences revision booklet 2024 Grade 10 Term 2 6.3. DIRECTION OF BLOOD FLOW 6.3.1 Pulmonary circulatory system Blood flows from the heart, to the lungs and back Deoxygenated blood flows into the right atrium and through the tricuspid valve into the right ventricle. The right ventricle pumps the blood through the pulmonary artery which divides into two branches, one to each lung In the lungs carbon dioxide diffuses out of the blood into the lungs and oxygen diffuses from the lungs into the blood Four pulmonary veins carry the oxygenated blood to the left atrium of the heart. 6.3.2 Systemic circulatory system Blood flows from the heart to the rest of the body and back. The left atrium receives oxygenated blood from the lungs via the four pulmonary veins The blood flows through the bicuspid valve into the left ventricle The left ventricle pumps the blood via the aorta and its branches to the rest of the body The upper part of the body receives blood via the subclavian artery and the carotid artery takes blood with oxygen to the brain. The hepatic artery transports blood to the liver and the mesenteric and gastric arteries transport blood to the intestines and the stomach. The hepatic portal vein transports blood from the stomach and intestines to the liver where nutrients are absorbed. The hepatic portal vein occurs between two organs and not between an organ and the heart. The renal artery provides the kidneys with oxygen and the renal vein transports deoxygenated blood to the heart. All the veins from the head and shoulders open into the vena cava superior. All the veins from the lower body opens into the vena cava inferior. Deoxygenated blood therefore flows back to the heart. 6.4 BLOOD VESSELS Artery Vein Capillary  20 Life Sciences revision booklet 2024 Grade 10 Term 2 6.4.1 Arteries Transport blood away from the heart The walls of arteries consist of three layers: an outer fibrous layer of connective tissue a middle layer of smooth muscle tissue and elastic fibres an inner layer of squamous epithelium, the endothelium The middle layer allows for the artery to stretch when blood is pumped under high pressure from the heart The thick muscular layer and elastic fibres helps the artery wall to resist the high pressure The lumen of an artery is smaller than that of a vein Arteries divide into thinner arteries, called arterioles Arteries have no valves. Only the aorta and pulmonary artery have semilunar valves. 6.4.2 Veins Veins transport blood back to the heart The walls of veins consist of the same three layers as arteries, but the outer two layers are thinner The lumen of a vein is larger than that of an artery Blood flows under very low pressure in veins The contraction of skeletal muscles close to veins helps the blood to move in the direction of the heart There are semilunar valves in veins which only allows blood to flow in one direction to the heart. Smaller veins are called venules. 6.4.3 Capillaries: Arterioles branch and later become microscopically small tubes, the capillaries The capillaries form a branched network between cells in the tissue The walls of capillaries consist only of one thin layer of endothelium The lumen of a capillary is very small and allows red blood corpuscles in the blood to move through in a single file. This slows the blood flow so that the exchange of gases and substances into and out of cells can take place more effectively. Capillaries join to form venules that connect to form veins.  21 Life Sciences revision booklet 2024 Grade 10 Term 2 7. REVISION QUESTIONS: Work through and answer the questions below. Please note that HIGHER ORDER questions are in BOLD and marked with a (*) 7.1 The diagrams below show different animal tissues. 7.1.1 Identify the animal tissues labelled: (a) IV (1) (b) V (1)  22 Life Sciences revision booklet 2024 Grade 10 Term 2 7.1.2 Identify part: (a) A (1) (b) B in diagram V (1) 7.1.3 Write down the LETTER(-S) only of the tissue(s) that … (a) is/are enclosed by a fibrous perichondrium. (1) (b) is/are found in the walls of the alimentary canal, bladder and uterus. (1) 7.1.4 Give TWO functions of the tissue labelled II (2) 7.2 The diagram below shows a cross section through a dicotyledonous root. 7.2.1 Identify part: (a) A (1) (b) B (1) 7.2.2 Give the LETTER and NAME of the part that: (a) gives rise to side/lateral roots (2) (b) transports organic food in the plant (2) (c) stores starch in the root (2) (d) transports water in the plant (2)  23 Life Sciences revision booklet 2024 Grade 10 Term 2 7.3 The diagram shows a cross section of a dicotyledonous leaf. 7.3.1 Give the LETTER of the part that: (a) is transparent and impermeable to water. (1) (b) transports water and mineral salts. (1) 7.3.2 What are parts C and D collectively called? (1) *7.3.3 Tabulate ONE structural difference between parts B and F. (3) * 7.3.4 Explain TWO ways in which part C is structurally adapted for its function of photosynthesis. (4) 7.4 The graphs below show the transpiration rates under different environmental conditions. *7.4.1 Describe the relationship between the temperature and transpiration rate in GRAPH A. (4) *7.4.2 Explain the shape of the graph at point X in GRAPH B. (3)  24 Life Sciences revision booklet 2024 Grade 10 Term 2 7.5 The diagram represents the pathway of water through the root. *7.5.1 If it has rained recently, give the LETTER in the diagram where the water potential will be the highest? (1) *7.5.2 Name TWO structural suitabilities of the root hair for the function of water absorption. (2) 7.5.3 Which LETTER in the diagram refers to the endodermis? (1) 7.5.4 Which special feature is present in the endodermis to control the pathway of water to the part labelled D? (1) 7.5.5 Name THREE forces responsible for the upward movement of water through tissue D. (3)  25 Life Sciences revision booklet 2024 Grade 10 Term 2 7.6 An investigation was carried out to study the effect of light intensity on the rate of water loss through the leaves of a plant. Apparatus X (shown in the diagram below) was used to measure the rate of water loss from the leaves at several light intensities. At each light intensity, the apparatus was left for 15 minutes before starting measurements. The water loss was recorded in the dark and at four different light intensities. The results of this investigation are shown in the table below. *7.6.1 State a hypothesis for this investigation. (2) *7.6.2 State the dependent variable in the above investigation. (1) *7.6.3 Predict what would be the effect on the results if the investigation was carried out at a lower temperature. (1) *7.6.4 State ONE way in which the reliability of the results obtained at each light intensity could have been improved. (1)  26 Life Sciences revision booklet 2024 Grade 10 Term 2 7.7 The diagrams below represent the human skull. 7.7.1 To which one of the two main sections of the skeleton do these structures belong? (1) 7.7.2 Identify the opening marked X. (1) 7.7.3 With which vertebra does this part of the skeleton articulate. (1) 7.7.4 Give the dental formula of a human. (2) 7.8 The diagram below shows a part of a human skeleton. 7.8.1 Give the LETTERS of TWO bones that make up the pectoral girdle. (2) 7.8.2 Identify parts: (a) F (1) (b) C (1)  27 Life Sciences revision booklet 2024 Grade 10 Term 2 7.9 The diagram below shows the internal structure of a human heart. 7.9.1 Identify parts: (a) A (1) (b) E (1) (c) G (1) 7.9.2 Give the LETTER and the NAME of the blood vessel that transports deoxygenated blood to the lungs. (2) 7.9.3 Where is the blood at C coming from? (1) 7.9.4 Name the phase of the heart cycle during which chambers D will contract? (1) 7.9.5 Will there be a high or low concentration of oxygen in the blood at part F? (1) 7.10 The heartbeat of two learners was recorded and plotted on a chart. Learner A stood still and Learner B ran up and down the stairs. Their heartbeat rates were recorded every minute. The graph below shows the results.  28 Life Sciences revision booklet 2024 Grade 10 Term 2 7.10.1 Which line, 1 or 2 represents the heartbeat rate of learner B? (1) 7.10.2 After how many minutes did the heartbeat rate of learner B, reach 185 beats per minute? (1) *7.10.3How does the heartbeat rate of learner A differ after 10 minutes from that of learner B? (2) 7.11 The diagrams below show transverse sections through a vein and an artery. 7.11.1 Identify parts: (a) A (1) (b) B (1) (c) C (1) 7.11.2 Which diagram (X or Y) represents an artery? (1) *7.11.3Explain your answer to QUESTION 7.11.2. (2) END OF DOCUMENT