B3: Organism level systems – GCSE OCR Foundation Biology revision notes

What this topic covers

B3: Organism level systems has 3 subtopics:

• B3.1 Coordination and control - the nervous system
• B3.2 Coordination and control - the endocrine system
• B3.3 Maintaining internal environments

B3: Organism level systems lessons by subtopic

20 lessons, grouped by subtopic.

B3.1 Coordination and control - the nervous system

• How the Nervous System Works: Explore the structure and function of the nervous system, including how it coordinates responses to stimuli and the pathway from stimulus to response.
• Reflex Actions and the Reflex Arc: Understand reflex actions, their importance, and how the structures in a reflex arc work together to produce rapid, automatic responses.
• Analysing Nervous System Data: Learn to extract and interpret data from graphs, charts and tables about nervous system function, including converting reaction time data between numerical and graphical forms.

B3.2 Coordination and control - the endocrine system

• Introduction to the Endocrine System: Learn about the principles of hormonal coordination and how the endocrine system works, including the role of glands, hormones, and target organs. Discover why the pituitary gland is called the 'master gland' and how hormonal control compares to nervous system control.
• Major Endocrine Glands and Their Locations: Identify and locate the key endocrine glands in the human body including the pituitary gland, pancreas, thyroid, adrenal glands, ovaries, and testes. Learn to recognise these glands on diagrams and understand their positions in the body.
• Adrenaline: The Fight or Flight Hormone: Explore how adrenaline is produced by the adrenal glands during stress or fear, and learn how it prepares the body for 'fight or flight' by increasing heart rate and boosting oxygen and glucose delivery to vital organs.
• Thyroxine: Metabolism and Feedback Control: Discover how thyroxine from the thyroid gland controls basal metabolic rate and supports growth and development, and understand how thyroxine levels are regulated through negative feedback mechanisms.
• Male and Female Reproductive Hormones: Explore the main reproductive hormones in males and females, including testosterone and oestrogen, and understand how they control puberty and the development of secondary sex characteristics.
• The Menstrual Cycle and Hormone Control: Understand the key hormones involved in the menstrual cycle including FSH, LH, oestrogen and progesterone, and learn how they work together to control egg maturation, ovulation and maintaining the uterus lining.
• Hormonal methods of contraception: Understanding how hormonal contraceptives work, including oral contraceptives that inhibit FSH production and slow-release progesterone methods such as injections, implants and patches that prevent egg maturation and release.
• Non-hormonal methods of contraception: Exploring barrier methods, intrauterine devices, spermicidal agents, natural family planning through abstinence timing, and surgical sterilisation methods for both males and females.
• Evaluating contraceptive methods: Comparing and evaluating the effectiveness, advantages and disadvantages of different hormonal and non-hormonal methods of fertility control to make informed decisions about contraception.
• Hormone Fertility Treatments: Learn how fertility drugs containing FSH and LH can help women with infertility issues to become pregnant naturally, and understand the broader context of modern reproductive technologies.
• IVF Process and Procedures: Explore the step-by-step process of In Vitro Fertilisation (IVF), from hormone stimulation to embryo implantation, understanding how this reproductive technology works.
• Challenges and Risks of Fertility Treatments: Examine the physical and emotional challenges of fertility treatments, their success rates, and the potential risks including multiple births for both mothers and babies.

B3.3 Maintaining internal environments

• What is Homeostasis and Why is it Important?: Understand the definition of homeostasis and explore the key conditions that need to be controlled in the human body, including blood glucose, body temperature, and water levels.
• How Control Systems Work in Homeostasis: Discover the three key components of all homeostatic control systems: receptors that detect changes, coordination centres that process information, and effectors that bring about responses.
• How the Pancreas Controls Blood Glucose: Learn how the pancreas monitors blood glucose levels and produces insulin to control high blood glucose by moving glucose into cells and converting excess glucose to glycogen for storage.
• Types of Diabetes and Their Treatment: Explore the differences between Type 1 and Type 2 diabetes, their causes, treatments, and risk factors. Learn to interpret graphs showing blood glucose levels in diabetic and non-diabetic individuals.
• Glucagon and Negative Feedback Control: Understand how glucagon works when blood glucose is too low and how insulin and glucagon interact in a negative feedback cycle to maintain blood glucose homeostasis.

More in this course

Go back to the full GCSE OCR Foundation Biology topic list, or practise this topic with past-paper questions.