Organism Level Systems | OCR GCSE Biology A, Foundation tier (J247)

Organism Level Systems

144 questions
13 subtopics
Paper 1
Paper 1

Organism Level Systems is examined in Biology A Paper 1.

It covers the nervous system and coordinated responses, the reflex arc, the eye and its common defects, the structure and function of the brain, hormones and the endocrine glands, hormones in reproduction and the menstrual cycle, methods of contraception, tropisms, auxin and the roles of plant hormones, homeostasis, and the skin in temperature control, insulin and the control of blood glucose, type 1 and type 2 diabetes, osmotic changes in body fluids, and the kidneys and kidney structure and the parts of the tubule.

Sample questions from Organism Level Systems

Answer each one closed book first, then open the answer.

The nervous system and coordinated responses

What is an effector?

Show the answer
A muscle or a gland that carries out the response when an impulse arrives from a motor neurone.
The reflex arc

In the blinking reflex, what is the stimulus and what is the effector?

Show the answer
The stimulus is an object touching the eye or moving quickly towards it, and the effector is the eyelid muscle.
The structure and function of the brain

Where is the cerebellum and what does it do?

Show the answer
It lies at the back of the brain beneath the cerebrum, and it coordinates muscle movement, balance and posture so movements are smooth.
Hormones and the endocrine glands

Where are the adrenal glands found?

Show the answer
One sits just above each kidney.
Methods of contraception

Give one advantage and one disadvantage of using the contraceptive pill.

Show the answer
It is more than 99% effective when taken correctly, but it can cause side effects such as headaches and raised blood pressure and gives no protection against sexually transmitted infections.
Tropisms, auxin and the roles of plant hormones

Name three processes in the life of a plant that are controlled by plant hormones.

Show the answer
Growth of the stem and roots, germination of seeds and ripening of fruit.
Insulin and the control of blood glucose

What effect does insulin have on the body cells?

Show the answer
It makes them take glucose out of the blood and into the cell.
Type 1 and type 2 diabetes

Give two symptoms of untreated diabetes.

Show the answer
Feeling very thirsty and needing to urinate often, along with tiredness and unexplained weight loss.

The 13 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
The nervous system and coordinated responses	The central nervous system, what sensory, motor and relay neurones, receptors and effectors do, how sensory and motor neurones differ in shape, synapses and neurotransmitters, what a coordinated response is and why many receptors and connections help, the stages from stimulus to response, catching a falling glass, and why nervous responses are faster than hormonal ones.	16
The reflex arc	What a reflex action is and why it protects the body, the parts of a reflex arc in order, why a reflex is faster than a voluntary action, the relay neurone in the spinal cord, how synapses slow an impulse, the hot pan and blinking reflexes, why a person is aware of a reflex, and why the same stimulus always gives the same response.	10
The eye and its common defects	The cornea, pupil, iris, retina with its rods and cones, and optic nerve, how the ciliary muscles and suspensory ligaments change the lens to focus on near and distant objects, red-green colour blindness, the causes of short- and long-sightedness and the concave and convex lenses that correct them, and contact lenses and surgery.	16
The structure and function of the brain	The cerebrum and its two hemispheres, the cerebral cortex, the cerebellum and its control of balance and movement, the medulla and why damage to it is life-threatening, the role of the hypothalamus, the pituitary gland as the master gland, and working out which region an injury has damaged.	10
Hormones and the endocrine glands	What a hormone and an endocrine gland are, how hormones travel in the blood yet affect only some organs, the main endocrine glands including the adrenal glands, the hormones of the ovaries and testes, and how hormonal and nervous responses compare.	8
Hormones in reproduction and the menstrual cycle	Testosterone and oestrogen and what each does at puberty, what FSH does and where it is released from, the role of progesterone, the length of the menstrual cycle and when an egg is released, and what happens to the uterus lining without fertilisation.	8
Methods of contraception	How the combined pill, other hormonal methods, condoms and other barrier methods prevent pregnancy, the advantages and disadvantages of each, sterilisation, why natural methods are less reliable, and which methods are the most effective.	8
Tropisms, auxin and the roles of plant hormones	Tropisms, phototropism and gravitropism, where auxin is made and how its uneven spread bends shoots towards light and roots downwards, the processes plant hormones control, and why controlling germination and shedding leaves before winter helps a plant.	10
Homeostasis, and the skin in temperature control	What homeostasis is and the conditions it keeps constant, why body temperature and blood water content must be controlled, the receptor, coordination centre and effector of a control system, how the skin and hypothalamus detect temperature, and how sweating, vasodilation, vasoconstriction and shivering correct body temperature, with why sweating works poorly on a humid day.	16
Insulin and the control of blood glucose	Which organ monitors blood glucose, how insulin makes body cells take up glucose, storing it as glycogen in the liver and muscles, why blood glucose falls after a meal and must be controlled, and insulin control as negative feedback.	8
Type 1 and type 2 diabetes	What type 1 and type 2 diabetes are, when each usually appears, insulin injections and why insulin cannot be swallowed, diet and exercise for type 2, risk factors, symptoms, and glucose in the urine.	10
Osmotic changes in body fluids, and the kidneys	What happens to animal, red blood and plant cells in dilute and concentrated solutions, lysis, why blood concentration must stay steady, the kidneys' roles in controlling water and salt and removing urea made in the liver, how urine changes with water intake and on hot days, filtration and selective reabsorption, and the path of urine to the bladder.	16
Kidney structure and the parts of the tubule	The cortex, medulla and renal pelvis, the renal artery and vein, what a kidney tubule is and how many a kidney holds, filtration at the Bowman's capsule and why proteins and blood cells stay in the blood, reabsorption in the proximal convoluted tubule, the role of the loop of Henlé, and the collecting duct.	8

Organism Level Systems is 144 of the 981 questions in the guide.Get the guide, £7

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.