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
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GCSE OCR Higher Combined Science Biology · Topic 3 of 6
B3: Organism level systems – GCSE OCR Higher Combined Science Biology revision notes
Choose a subtopic. Nervous control, endocrine control and homeostasis. 20 lessons in 3 subtopics.
Revise B3: Organism level systems for GCSE OCR Higher Combined Science Biology, including B3.1 Coordination and control - the nervous system.
20
Lessons
3
Subtopics
B3: Organism level systems lessons by subtopic
20 lessons, grouped by subtopic.
B3.1 Coordination and control - the nervous system
B3.2 Coordination and control - the endocrine system
- Introduction to the Endocrine System
- Major Endocrine Glands and Their Locations
- Adrenaline: The Fight or Flight Hormone
- Thyroxine: Metabolism and Feedback Control
- Male and Female Reproductive Hormones
- The Menstrual Cycle and Hormone Control
- Hormonal methods of contraception
- Non-hormonal methods of contraception
- Evaluating contraceptive methods
- Hormone Fertility Treatments
- IVF Process and Procedures
- Challenges and Risks of Fertility Treatments
B3.3 Maintaining internal environments
More in this course
Go back to the full GCSE OCR Higher Combined Science Biology topic list, or practise this topic with past-paper questions.
Frequently asked questions
What is B3: Organism level systems?
Nervous control, endocrine control and homeostasis. 20 lessons in 3 subtopics.
What are the four stages of the menstrual cycle?
The menstrual cycle has menstruation (days 1-5), when the lining is shed and FSH rises; the follicular phase (days 6-13), when an egg matures and oestrogen thickens the lining; ovulation (day 14), triggered by the LH surge; and the luteal phase (days 15-28), when progesterone maintains the lining. The The Menstrual Cycle and Hormone Control notes cover this in full.
What is ovulation?
Ovulation is the release of a mature egg from the ovary, occurring approximately every 28 days in the menstrual cycle. The Male and Female Reproductive Hormones notes cover this in full.
What is a vasectomy?
A vasectomy is male sterilisation: surgical cutting or blocking of the vas deferens tubes so sperm cannot mix with semen during ejaculation. The Non-hormonal methods of contraception notes cover this in full.
What are the side effects of the combined pill?
Side effects of the combined pill can include nausea and mood changes, and there is a small increased risk of blood clots. The Evaluating contraceptive methods notes cover this in full.
What is homeostasis?
Homeostasis is the regulation of internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes. The What is Homeostasis and Why is it Important? notes cover this in full.
What is the normal blood glucose range?
The normal blood glucose range is 4.4-6.1 mmol/L. The Glucagon and Negative Feedback Control notes cover this in full.
What is basal metabolic rate?
Basal metabolic rate (BMR) is the minimum rate of energy expenditure needed to maintain basic body functions at rest, measured in kilojoules per day. The Thyroxine: Metabolism and Feedback Control notes cover this in full.
Where is the pancreas located?
The pancreas is an elongated gland located behind the stomach. The Major Endocrine Glands and Their Locations notes cover this in full.