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Defense against infectious disease / Gas exchange
Nerves, hormones, homeostasis
Reproduction
Digestion and transport system
HL only
100
What is a ventilation system needed for in living organisms? A) To pump oxygen into the pulmonary artery. B) To pump oxygen into the pulmonary vein. C) To increase the rate of cell respiration in the alveoli. D) To maintain high concentration gradients in the alveoli.
D
100
The movement of which ion initiates an action potential? A) calcium B) magnesium C) sodium D) potassium
C
100
What is in vitro fertilization? A) Fertilization using donated sperm. B) Artificial fertilization of an egg inside the body. C) Fertilization of an egg outside the body. D) Cloning technique to help couples conceive.
C
100
Distinguish between absorption and assimilation.
Absorption: Food molecules enter the body and into the blood stream. Assimilation: Food molecules used in a particular tissue.
100
A blood clot contains a network of protein. What is the protein? A) Fibrin B) Fibrinogen C) Haemoglobin D) Thrombin
A
200
What causes air to flow through the airways to the lungs? A) Contraction of the internal intercostal muscles. B) Contraction of the muscles in the abdomen wall. C) An increase in volume of the thorax. D) An increase in pressure in the thorax.
C
200
What is the role of active transport in the transmission of nerve impulses by neurons? A) Propagates an action potential by pumping sodium ions across the membrane out of the neuron. B) Propagates an action potential by pumping sodium ions across the membrane into the neuron. C) Initiates the action potential needed for the transmission of an impulse by pumping calcium ions out of the endoplasmic reticulum. D) Establishes the resting potential needed for the transmission of an impulse by pumping sodium and potassium ions across the membrane.
D
200
List two roles of testosterone in males [1].
Pre-natal development of male genitalia; development of male secondary sexual characteristics; maintenance of sex drive
200
List four components of the blood.
Plasma, erythrocytes, leucocytes and platlets
200
How do the levels of oxytocin and progesterone change immediately prior to birth? A) Oxytocin decreases, progesterone decreases B) oxytocin decreases, progesterone increases C) oxytocin increases, progesterone decreases D) oxytocin increases, progesterone increases
C
300
Explain why HIV infection leads to decreased effectiveness of the immune system [3].
T-cells are involved in activating specific immune response; HIV targets T-cells specifically/reduces number of circulating T-cells; leads to reduced ability to develop specific immune response.
300
Distinguish between Type I diabetes and Type II diabetes [2].
Type I diabetes is due to low insulin production by pancreas and Type II diabetes is to to poor response of cells to insulin; There is a stronger dietary link to Type II diabetes.
300
Draw and label a diagram of the male reproductive system [5].
Testes; sperm duct; penis; urethra; prostate gland; seminal vesicle; epididymis
300
Draw and label a diagram of the heart [5].
four chambers, blood vessels, valves, direction of blood flow
300
State the names of the processes used to reabsorb water and salts.
Water is osmosis and salts by active transport / facilitated diffusion.
400
Draw a diagram of the human gas exchange system [5].
mouth/nose; trachea; bronchi; brochioles; lungs; alveoli; diaphragm; ribs/intercostal muscles
400
Using an example, explain the role of negative feedback in homeostasis [3].
A rise in level would feedback to decrease production; as levels drop to low this would feedback to increase production; eg: blood glucose concentration / body temperature
400
Draw and label a diagram of the female reproductive system.
Ovary; oviduct / follapian tube; uterus; cervix; vagina
400
State the source, substrate, product and optimum pH condition for a protease (ex: pepsin).
Source: stomach lining Substrate: Proteins Product: Smaller Polypeptides pH: 1.5-2
400
Compare the composition of blood arriving at the kidney with the composition of blood carried away from it [4].
More oxygen in the renal artery / less in the renal vein / oxygenated vs deoxygenated; less carbon dioxide in the renal artery / more in the renal vein; more urea in the renal artery / less in the renal vein; more ammonia / ethanol / toxins / hormones in the renal artery / less in the renal vein; more salts in renal artery than in renal vein; more water in renal artery than in renal vein; lower salt concentration / higher water concentration in vein with ADH
500
Discuss the mechanism of ventilation in the human lung [5].
consists of inhaling and exhaling air / exchanging stale air with fresh air (with the environment); external intercostal muscles contract moving the rib cage up / out; diaphragm contracts; increases volume in thorax / lowers lung pressure relative to air pressure / pulls air in; diaphragm relaxes; abdominal muscles contract; internal intercostal muscles contract moving the rib cage down / in; force air out / decreases volume of thorax / raise lung pressure relative to air pressure
500
Explain the control of body temperature in response to heating and cooling [5].
Response to heating: Arterioles that bring blood to skin dilate and vessels that bypass it constrict; skin warms up so there is a larger temperature difference between the environment and skin so heat is lost; sweat glands secrete sweat through the skin cooling the surface. Response to cooling: Blood flow brings heat from core of the body to skin, replacing heat lost to environment; arterioles constrict; shivering of skeletal muscles.
500
Explain the changes in the endometrium during a menstrual cycle in terms of hormone levels and the timing of ovlulation and implantation.
Lining of the uterus is shed during menstrutation; rising levels of estrogen; cause the thickening of the uterus lining / endometrium; in the days before ovulation; rising progesterone levels; maintain the thickened uterus lining / endometrium; endometrium is thickened at the time of implantation; falling progesterone levels cause the uterus lining / endometrium to break down
500
Outline the control of the heartbeat in terms of myogenic muscle contraction (5 marks)
Heart can contract by itself. Pacemaker is found in the right atrium known as the sinoatrial node and controls the rate of the heart beat. Excitations causes atria to contract. This excites the atrioventricular node, which sends to ventricles to contract those. Heart rate is controlled by the autonomic nervous system. Change in CO2 or adrenaline can be picked up by chemoreceptors in the medulla oblongata, which sends a signal via the vagus nerve to the pacemaker.
500
Explain how a muscle fiber contracts, following depolarization of its plasma membrane [6].
Calcium released from sarcoplasmic reticulum; calcium binds to troponin; troponin with calcium bound makes tropomyosin move; movement of tropomyosin exposes binding sites for myosin on actin; contraction of muscles fibres is due to the sliding of filaments (over each other); myosin heads bind to / form cross-bridges with actin; ATP binds to the myosin heads causing them to detach from the binding sites; hydrolysis of ATP / conversion of ATP to ADP causes myosin heads to move; myosin heads reattach to actin further along; myosin pushes actin / actin pushes towards the center of sarcomere / shortening of sarcomere