Science 0653 — specification explorer

1. Characteristics of living organisms

• B1.1.1

  Describe the characteristics of living organisms by defining the terms: causing a change of position or place that break down nutrient molecules and release energy to changes in the environment more of the same kind of organism toxic materials and substances in excess of requirements growth and development:

  • movement as an action by an organism
  • respiration as the chemical reactions in cells
  • sensitivity as the ability to detect and respond
  • growth as a permanent increase in size
  • reproduction as the processes that make
  • excretion as removal from organisms of
  • nutrition as taking in of materials for energy,
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1. Cell structure

• B2.1.1State that living organisms are made of cells
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• B2.1.2Describe and compare the structure of a plant cell with an animal cell, as seen under a light microscope, limited to cell wall, nucleus, cytoplasm, chloroplasts, vacuoles and location of the cell membrane
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• B2.1.3State the functions of the structures seen under the light microscope in the plant cell and in the animal cell specimens using millimetres as units
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• B2.1.4

  Relate the structure of the following to their functions: trachea and bronchi:

  • ciliated cells – movement of mucus in the
  • root hair cells – absorption
  • palisade mesophyll cells – photosynthesis
  • red blood cells – transport of oxygen
  • sperm and egg cells – reproduction
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2. Movement in and out of cells

• B2.2.1Define diffusion as the net movement of particles from a region of their higher concentration to a region of their lower concentration down a concentration gradient, as a result of their random movement
• B2.2.2State that substances move into and out of cells by diffusion through the cell membrane
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• B2.2.3State that water diffuses through partially permeable membranes by osmosis osmosis through the cell membrane tissues of immersing them in solutions of different concentrations
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• B2.2.4Define osmosis as the net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane
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1. Biological molecules

• B3.1.1

  List the chemical elements that make up:

  • carbohydrates
  • fats
  • proteins
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• B3.1.2

  State that large molecules are made from smaller molecules, limited to:

  • starch and glycogen from glucose
  • proteins from amino acids
  • fats and oils from fatty acids and glycerol
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• B3.1.3

  Describe the use of: sugars:

  • iodine solution to test for starch
  • Benedict’s solution to test for reducing
  • biuret test for proteins
  • ethanol emulsion test for fats and oils
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• B3.1.4State that water is important as a solvent

1. Enzymes

• B4.1.1Define enzymes as proteins that function as biological catalysts temperature and pH on enzyme activity
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• B4.1.2Explain enzyme action with reference to the complementary shape of the active site of an enzyme and its substrate and the formation of a product enzyme activity, in terms of kinetic energy, shape and fit, frequency of effective collisions and denaturation enzyme activity in terms of shape and fit and denaturation
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1. Plant nutrition

• B5.1.1Define photosynthesis as the process by which plants manufacture carbohydrates from raw materials using energy from light
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• B5.1.2

  State the word equation for photosynthesis: carbon dioxide + water → glucose + oxygen, in the presence of light and chlorophyll and carbon dioxide for photosynthesis, using appropriate controls stomata, upper and lower epidermis, palisade mesophyll, spongy mesophyll, vascular bundles, xylem and phloem in leaves of a dicotyledonous plant:

  • nitrate ions for making amino acids
  • magnesium ions for making chlorophyll
• B5.1.3State the balanced equation for photosynthesis light
• B5.1.4Explain that chlorophyll transfers light energy into chemical energy in molecules, for the synthesis of carbohydrates
• B5.1.5

  Outline the subsequent use and storage of the carbohydrates made in photosynthesis light intensity and temperature on the rate of photosynthesis (e.g. in submerged aquatic plants) in terms of functions, to include: chloroplasts – photosynthesis cells – gas exchange ion deficiency on plant growth:

  • palisade mesophyll and distribution of
  • stomata, spongy mesophyll cells and guard
  • xylem for transport and support
  • phloem for transport

1. Diet

• B6.1.1State what is meant by the term balanced diet for humans
• B6.1.2

  List the principal sources of, and describe the dietary importance of:

  • carbohydrates
  • fats
  • proteins
  • vitamins, limited to C and D
  • mineral salts, limited to calcium and iron
  • fibre (roughage)
  • water
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• B6.1.3Explain how age, gender and activity affect the dietary needs of humans including during pregnancy and while breast-feeding
• B6.1.4Describe the effects of malnutrition in relation to starvation, constipation, coronary heart disease, obesity and scurvy
• B6.1.5Explain the causes and effects of vitamin D and iron deficiencies

2. Alimentary canal

• B6.2.1Define ingestion as the taking of substances, e.g. food and drink, into the body through the mouth
• B6.2.2Define digestion as the breakdown of large, insoluble food molecules into small, water- soluble molecules using mechanical and chemical processes food molecules and ions through the wall of the intestine into the blood has not been digested or absorbed, as faeces, through the anus and associated organs, limited to mouth, salivary glands, oesophagus, stomach, small intestine, pancreas, liver, gall bladder, large intestine and anus alimentary canal listed above, in relation to ingestion, digestion, absorption and egestion of food
• B6.2.3Define mechanical digestion as the breakdown of food into smaller pieces without chemical change to the food molecules
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• B6.2.4Define chemical digestion as the breakdown of large, insoluble molecules into small, soluble molecules

3. Digestion

• B6.3.1State the significance of chemical digestion in the alimentary canal in producing small, soluble molecules that can be absorbed
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• B6.3.2

  State the functions of enzymes as follows: sugars glycerol:

  • amylase breaks down starch to simpler
  • protease breaks down protein to amino acids
  • lipase breaks down fats to fatty acids and
• B6.3.3State where, in the alimentary canal, amylase, protease and lipase are secreted
• B6.3.4State the functions of the hydrochloric acid in gastric juice, limited to killing bacteria in food and giving an acid pH for enzymes

1. Transport in plants

• B7.1.1State the functions of xylem and phloem
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• B7.1.2Identify the position of xylem as seen in sections of roots, stems and leaves, limited to non-woody dicotyledonous plants
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• B7.1.3Identify root hair cells, as seen under the light microscope, and state their functions stem and leaf as root hair cell, root cortex cells, xylem and mesophyll cells water through the above-ground parts of a plant leaves through the xylem vessels from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapour through the stomata of temperature and humidity on transpiration rate
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• B7.1.4Explain that the large surface area of root hairs increases the rate of the absorption of water and humidity on transpiration rate

2. Transport in mammals

• B7.2.1

  Describe the circulatory system as a system of blood vessels with a pump and valves to ensure one-way flow of blood mammalian heart, limited to the muscular wall, the septum, the left and right ventricles and atria, one-way valves and coronary arteries into arteries and returns to the heart in veins artery and pulmonary vein pulmonary vein activity on pulse rate veins and capillaries white blood cells, platelets and plasma the light microscope, on prepared slides and in diagrams and photomicrographs of blood: including the role of haemoglobin antibody production soluble nutrients, hormones and carbon dioxide:

  • heart, limited to vena cava, aorta, pulmonary
  • lungs, limited to the pulmonary artery and
  • red blood cells in transporting oxygen,
  • white blood cells in phagocytosis and
  • platelets in clotting (details are not required)
  • plasma in the transport of blood cells, ions,
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• B7.2.2Describe double circulation in terms of circulation to the lungs and circulation to the body tissues in mammals
• B7.2.3Explain the advantages of a double circulation of the contraction of muscles of the atria and ventricles and the action of the valves the blockage of coronary arteries and state the possible risk factors as diet, stress, smoking, genetic predisposition, age and gender rate capillaries are adapted for their function

1. Gas exchange

• B8.1.1Name and identify the lungs, diaphragm, ribs, intercostal muscles, larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries inspired and expired air limited to oxygen, carbon dioxide and water vapour to investigate the differences in composition between inspired and expired air activity on rate and depth of breathing
• B8.1.2List the features of gas exchange surfaces in animals, limited to large surface area, thin surface, good blood supply and good ventilation with air inspired and expired air and depth of breathing in terms of the increased carbon dioxide concentration in the blood, causing an increased rate of breathing ciliated cells in protecting the gas exchange system from pathogens and particles obstructive pulmonary disease (COPD), lung cancer and coronary heart disease system of tobacco smoke and its major toxic components, limited to carbon monoxide, nicotine and tar
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2. Respiration

• B8.2.1State the uses of energy in the body of humans limited to: muscle contraction, protein synthesis, growth and the maintenance of a constant body temperature as glucose + oxygen → carbon dioxide + water
• B8.2.2Define aerobic respiration as the chemical reactions in cells that use oxygen to break down nutrient molecules to release energy respiration as C H O + 6O → 6CO + 6H O

1. Hormones in humans

• B9.1.1Define a hormone as a chemical substance, produced by a gland, carried by the blood, which alters the activity of one or more specific target organs
• B9.1.2Describe adrenaline as the hormone secreted in ‘fight or flight’ situations and its effects, limited to increased breathing and pulse rate and widened pupils secretion increases
• B9.1.3Discuss the role of the hormone adrenaline in the chemical control of metabolic activity, including increasing the blood glucose concentration and pulse rate

2. Tropic responses

• B9.2.1Define gravitropism as a response in which parts of a plant grow towards or away from gravity
• B9.2.2Define phototropism as a response in which parts of a plant grow towards or away from the direction from which light is coming shoots and roots
• B9.2.3

  Explain phototropism and gravitropism of a shoot as examples of the chemical control of plant growth growth, limited to: shoot tip light and gravity:

  • auxin made in shoot tip (only)
  • auxin spreads through the plant from the
  • auxin is unequally distributed in response to
  • auxin stimulates cell elongation

1. Asexual and sexual reproduction

• B10.1.1Define asexual reproduction as a process resulting in the production of genetically identical offspring from one parent
• B10.1.2Identify examples of asexual reproduction from information provided
• B10.1.3Define sexual reproduction as a process involving the fusion of the nuclei of two gametes (sex cells) to form a zygote and the production of offspring that are genetically different from each other

2. Sexual reproduction in plants

• B10.2.1Identify and draw, using a hand lens if necessary, the sepals, petals, stamens, filaments and anthers, carpels, style, stigma, ovary and ovules, of an insect-pollinated flower stigmas and ovaries from the anther to the stigma nucleus fuses with a nucleus in an ovule conditions that affect germination of seeds: limited to the requirement for water, oxygen and a suitable temperature
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• B10.2.2Use a hand lens to identify and describe the anthers and stigmas of a wind-pollinated flower pollinated and wind-pollinated flowers pollinated and wind-pollinated flowers continued
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3. Sexual reproduction in humans

• B10.3.1Identify and name on diagrams of the male reproductive system: the testes, scrotum, sperm ducts, prostate gland, urethra and penis
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• B10.3.2

  State the function of the parts of the male reproductive system limited to: the body swim in forming semen body sexual intercourse:

  • testes – production of male gametes (sperm)
  • scrotum – sac that holds the testes outside
  • sperm ducts – transfer sperm to the urethra
  • prostate gland – secrete fluids for sperm to
  • urethra – carries urine and semen out of the
  • penis – transfers semen to vagina during
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• B10.3.3Identify and name on diagrams of the female reproductive system: the ovaries, oviducts, uterus, cervix and vagina
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• B10.3.4

  State the function of the parts of the female reproductive system limited to: of fertilisation uterus intercourse:

  • ovaries – release of female gametes (eggs)
  • oviducts – transfers egg to uterus and the site
  • uterus – where the fetus develops
  • cervix – ring of muscle at the opening of the
  • vagina – receives penis during sexual
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• B10.3.5Describe fertilisation as the fusion of the nuclei from a male gamete (sperm) and a female gamete (egg cell/ovum) in the ovaries and in the lining of the uterus (knowledge of sex hormones is not required) forms an embryo which is a ball of cells that implants into the wall of the uterus (HIV) infection may lead to acquired immune deficiency syndrome (AIDS) infections (STIs) is controlled
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• B10.3.6Compare male and female gametes in terms of size, structure, motility and numbers
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• B10.3.7State the adaptive features of sperm, limited to flagellum and the presence of enzymes
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• B10.3.8State the adaptive features of egg cells, limited to energy stores and a jelly coating that changes after fertilisation placenta, amniotic sac and amniotic fluid umbilical cord in relation to exchange of dissolved nutrients, gases and excretory products and providing a barrier to toxins (structural details are not required)
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1. Organisms and their environment

• B11.1.1State that the Sun is the principal source of energy input to biological systems
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• B11.1.2

  Define the terms: from one organism to the next, beginning with a producer food chains organic nutrients, usually using energy from sunlight, through photosynthesis by feeding on other organisms eating plants eating other animals energy from dead or waste organic matter identifying producers and consumers secondary and tertiary according to their position in a food chain:

  • food chain as showing the transfer of energy
  • food web as a network of interconnected
  • producer as an organism that makes its own
  • consumer as an organism that gets its energy
  • herbivore as an animal that gets its energy by
  • carnivore as an animal that gets its energy by
  • decomposer as an organism that gets its
• B11.1.3

  Define the terms: organisms and their environment, interacting together, in a given area, e.g. a lake a food chain or food web:

  • ecosystem as a unit containing all of the
  • trophic level as the position of an organism in
• B11.1.4Describe how energy is transferred between trophic levels
• B11.1.5Explain why food chains usually have fewer than five trophic levels secondary consumers, tertiary consumers and quaternary consumers as the trophic levels in food webs and food chains

1. Human influences on ecosystems

• B12.1.1Describe the carbon cycle, limited to photosynthesis, respiration, feeding, decomposition, fossilisation and combustion an example of habitat destruction, to include extinction, loss of soil, flooding and increase of carbon dioxide in the atmosphere
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• B12.1.2

  Discuss the effects of the combustion of fossil fuels and the cutting down of forests on the oxygen and carbon dioxide concentrations in the atmosphere terms of: producers oxygen in water:

  • increased availability of nitrate and other ions
  • increased growth of producers
  • increased decomposition after death of
  • increased aerobic respiration by decomposers
  • reduction in dissolved oxygen
  • death of organisms requiring dissolved