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EnglandBiology

B3 Organism level systems

6 dot points across 6 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How does the body keep blood glucose steady, and what goes wrong in diabetes?

The control of blood glucose concentration by insulin and glucagon, the roles of the pancreas and liver, negative feedback, and the causes and treatment of type 1 and type 2 diabetes.
A focused answer to the OCR Gateway GCSE Biology A topic B3 on the control of blood glucose, covering insulin and glucagon, the pancreas and liver, negative feedback, and the causes and treatment of type 1 and type 2 diabetes.
10 min answer →

Which hormones control the menstrual cycle, and how can they be used to prevent or help pregnancy?

The hormones controlling the menstrual cycle (FSH, LH, oestrogen, progesterone), the events of the menstrual cycle, hormonal and barrier methods of contraception, and fertility treatments including IVF.
A focused answer to the OCR Gateway GCSE Biology A topic B3 on hormones in human reproduction, covering FSH, LH, oestrogen and progesterone, the menstrual cycle, contraception and fertility treatments including IVF.
10 min answer →

How do plants sense light and gravity, and how do we use plant hormones in farming?

Auxins as plant hormones controlling growth, phototropism and gravitropism (geotropism), how auxin distribution produces tropic responses, and the commercial uses of plant hormones.
A focused answer to the OCR Gateway GCSE Biology A topic B3 on plant hormones, covering auxins, phototropism and gravitropism, how auxin distribution produces tropic responses, and the commercial uses of plant hormones.
9 min answer →

What do the main regions of the brain do, and how does the eye focus light onto the retina?

The functions of the main regions of the brain (cerebral cortex, cerebellum, medulla), the structure of the eye and how it focuses light, accommodation, and how the eye responds to changes in light intensity (Higher tier content).
A focused answer to the OCR Gateway GCSE Biology A topic B3 Higher content on the brain and the eye, covering the cerebral cortex, cerebellum and medulla, the structure of the eye, focusing and accommodation, and the iris reflex.
9 min answer →

How do hormones control the body, and how is hormonal control different from nervous control?

The endocrine system as glands that secrete hormones into the blood, hormones acting on target organs with the correct receptors, the main endocrine glands, and a comparison of nervous and hormonal control.
A focused answer to the OCR Gateway GCSE Biology A topic B3 on the endocrine system, covering glands and hormones, target organs and receptors, the main endocrine glands, and how hormonal control compares with nervous control.
9 min answer →

How does the nervous system let you detect a stimulus and respond, sometimes without thinking?

The central nervous system, sensory, relay and motor neurones, synapses and neurotransmitters, the reflex arc as a fast automatic response, and reaction time and the factors affecting it.
A focused answer to the OCR Gateway GCSE Biology A topic B3 on the nervous system, covering the central nervous system, the three types of neurone, synapses and neurotransmitters, the reflex arc, and reaction time.
9 min answer →