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Science

KS4 – Year 11 – AQA GCSE BIOLOGY

Course overview

In Year 11 students study the AQA GCSE Biology course. This qualification is linear. Linear means that students will sit all their exams at the end of the course. In order to achieve this qualification, students must complete 10 required practical and two examinations at the end of the course.

GCSE study in biology provides the foundations for understanding the material world. Scientific understanding is changing our lives and is vital to the world’s future prosperity, and all students should be taught essential aspects of the knowledge, methods, processes and uses of science. They are helped to appreciate how the complex and diverse phenomena of the natural world can be described in terms of a small number of key ideas relating to the sciences which are both inter-linked, and are of universal application. These key ideas include:

  • the use of conceptual models and theories to make sense of the observed diversity of natural phenomena
  • the assumption that every effect has one or more cause
  • that change is driven by differences between different objects and systems when they interact
  • that many such interactions occur over a distance without direct contact
  • that science progresses through a cycle of hypothesis, practical experimentation, observation, theory development and review
  • that quantitative analysis is a central element both of many theories and of scientific methods of inquiry.
     

The GCSE specification in biology enables students to:

  • develop scientific knowledge and conceptual understanding of biology
  • develop understanding of the nature, processes and methods of biology through different types of scientific enquiries that help them to answer scientific questions about the world around them
  • develop and learn to apply observational, practical, modelling, enquiry and problem-solving skills, both in the laboratory, in the field and in other learning environments
  • develop their ability to evaluate claims based on biology through critical analysis of the methodology, evidence and conclusions, both qualitatively and quantitatively.

Subject topic areas:

  • 1. Cell biology
  • 2. Organisation
  • 3. Infection and response
  • 4. Bioenergetics
  • 5. Homeostasis and response
  • 6. Inheritance, variation and evolution
  • 7. Ecology
  • 8. Key ideas

Cell biology
Cells are the basic unit of all forms of life. In this section we explore how structural differences between types of cells enables them to perform specific functions within the organism. These differences in cells are controlled by genes in the nucleus. For an organism to grow, cells must divide by mitosis producing two new identical cells. If cells are isolated at an early stage of growth before they have become too specialised, they can retain their ability to grow into a range of different types of cells. This phenomenon has led to the development of stem cell technology. This is a new branch of medicine that allows doctors to repair damaged organs by growing new tissue from stem cells.

Organisation

In this section we will learn about the human digestive system which provides the body with nutrients and the respiratory system that provides it with oxygen and removes carbon dioxide. In each case they provide dissolved materials that need to be moved quickly around the body in the blood by the circulatory system. Damage to any of these systems can be debilitating if not fatal. Although there has been huge progress in surgical techniques, especially with regard to coronary heart disease, many interventions would not be necessary if individuals reduced their risks through improved diet and lifestyle. We will also learn how the plant’s transport system is dependent on environmental conditions to ensure that leaf cells are provided with the water and carbon dioxide that they need for photosynthesis.

Infection and response

Pathogens are microorganisms such as viruses and bacteria that cause infectious diseases in animals and plants. They depend on their host to provide the conditions and nutrients that they need to grow and reproduce. They frequently produce toxins that damage tissues and make us feel ill. This section will explore how we can avoid diseases by reducing contact with them, as well as how the body uses barriers against pathogens. Once inside the body our immune system is triggered which is usually strong enough to destroy the pathogen and prevent disease. When at risk from unusual or dangerous diseases our body’s natural system can be enhanced by the use of vaccination. Since the 1940s a range of antibiotics have been developed which have proved successful against a number of lethal diseases caused by bacteria. Unfortunately many groups of bacteria have now become resistant to these antibiotics. The race is now on to develop a new set of antibiotics.

Bioenergetics

 In this section we will explore how plants harness the Sun’s energy in photosynthesis in order to make food. This process liberates oxygen which has built up over millions of years in the Earth’s atmosphere. Both animals and plants use this oxygen to oxidise food in a process called aerobic respiration which transfers the energy that the organism needs to perform its functions. Conversely, anaerobic respiration does not require oxygen to transfer energy. During vigorous exercise the human body is unable to supply the cells with sufficient oxygen and it switches to anaerobic respiration. This process will supply energy but also causes the build-up of lactic acid in muscles which causes fatigue.

Homeostasis and response

 Cells in the body can only survive within narrow physical and chemical limits. They require a constant temperature and pH as well as a constant supply of dissolved food and water. In order to do this the body requires control systems that constantly monitor and adjust the composition of the blood and tissues. These control systems include receptors which sense changes and effectors that bring about changes. In this section we will explore the structure and function of the nervous system and how it can bring about fast responses. We will also explore the hormonal system which usually brings about much slower changes. Hormonal coordination is particularly important in reproduction since it controls the menstrual cycle. An understanding of the role of hormones in reproduction has allowed scientists to develop not only contraceptive drugs but also drugs which can increase fertility

Inheritance, variation and evolution

 In this section we will discover how the number of chromosomes are halved during meiosis and then combined with new genes from the sexual partner to produce unique offspring. Gene mutations occur continuously and on rare occasions can affect the functioning of the animal or plant. These mutations may be damaging and lead to a number of genetic disorders or death. Very rarely a new mutation can be beneficial and consequently, lead to increased fitness in the individual. Variation generated by mutations and sexual reproduction is the basis for natural selection; this is how species evolve. An understanding of these processes has allowed scientists to intervene through selective breeding to produce livestock with favoured characteristics. Once new varieties of plants or animals have been produced it is possible to clone individuals to produce larger numbers of identical individuals all carrying the favourable characteristic. Scientists have now discovered how to take genes from one species and introduce them in to the genome of another by a process called genetic engineering. In spite of the huge potential benefits that this technology can offer, genetic modification still remains highly controversial.

Ecology

The Sun is a source of energy that passes through ecosystems. Materials including carbon and water are continually recycled by the living world, being released through respiration of animals, plants and decomposing microorganisms and taken up by plants in photosynthesis. All species live in ecosystems composed of complex communities of animals and plants dependent on each other and that are adapted to particular conditions, both abiotic and biotic. These ecosystems provide essential services that support human life and continued development. In order to continue to benefit from these services humans need to engage with the environment in a sustainable way. In this section we will explore how humans are threatening biodiversity as well as the natural systems that support it. We will also consider some actions we need to take to ensure our future health, prosperity and well-being.

Key ideas

The complex and diverse phenomena of the natural world can be described in terms of a small number of key ideas in biology. These key ideas are of universal application, and we have embedded them throughout the subject content. They underpin many aspects of the science assessment. These ideas include: • life processes depend on molecules whose structure is related to their function • the fundamental units of living organisms are cells, which may be part of highly adapted structures including tissues, organs and organ systems, enabling living processes to be performed effectively • living organisms may form populations of single species, communities of many species and ecosystems, interacting with each other, with the environment and with humans in many different ways • living organisms are interdependent and show adaptations to their environment • life on Earth is dependent on photosynthesis in which green plants and algae trap light from the Sun to fix carbon dioxide and combine it with hydrogen from water to make organic compounds and oxygen • organic compounds are used as fuels in cellular respiration to allow the other chemical reactions necessary for life • the chemicals in ecosystems are continually cycling through the natural world • the characteristics of a living organism are influenced by its genome and its interaction with the environment • evolution occurs by a process of natural selection and accounts both for biodiversity and how organisms are all related to varying degrees.

GCSE exams in Biology

The exams include questions that allow students to demonstrate: • their knowledge and understanding of the content developed in one section or topic, including the associated mathematical and practical skills or • their ability to apply mathematical and practical skills to areas of content they are not normally developed in or • their ability to draw together different areas of knowledge and understanding within one answer. A range of question types will be used, including multiple choice, short answer and those that require extended responses. Extended response questions will be of sufficient length to allow students to demonstrate their ability to construct and develop a sustained line of reasoning which is coherent, relevant, substantiated and logically structured. Extended responses may be prose, extended calculations,

Paper 1:

What's assessed:

Topics 1–4: Cell biology; Organisation; Infection and response; and Bioenergetics.

How it's assessed:

Written exam: 1 hour 45 minutes
Foundation and Higher Tier
100 marks
50% of GCSE

Questions: Multiple choice, structured, closed short answer and open response.

Paper 2:

What's assessed:

Topics 5–7: Homeostasis and response; Inheritance, variation and evolution; and Ecology.

How it's assessed:

Written exam: 1 hour 45 minutes
Foundation and Higher Tier
100 marks
50% of GCSE

Questions: Multiple choice, structured, closed short answer and open response.

 

Required practical activities

  • 1 Microscopy - Cell Biology
  • 2 Osmosis - Cell Biology
  • 3 Food Tests - Organisation
  • 4 Enzymes - Homeostasis and Response
  • 5 Reaction Time - Homeostasis and Response
  • 6 Decay - Infection and Response
  • 7 Microbiology - Infection and Response
  • 8 Photosynthesis - Bioenergetics
  • 9 Germination - Bioenergetics
  • 10 Field Investigation - Ecology