Welcome to your Eduqas Component 3 Which of the following is not a characteristic of a double circulation? Mixing of oxygenated and deoxygenated blood. Presence of 2 atria and 2 completely seperated ventricles. Left side handles oxygenated blood. Right side handles deoxygenated blood. Vessels carrying blood away from the heart. Arteries Veins Capillaries Tubules The mammalian circulatory system is a ___________. Closed double circulation Open double circulation Pulmonary circulation Systemic circulation Fine network-like structure containg one-cell thick blood vessels are called Capillaries Arterioles Veins Ventricoules Vessels carrying blood towards the heart. Veins Arteries Capillaries Tubes At which stage in cardiac cycle do both ventricles and atria get relaxed? Cardiac Diastole Cardiac Systole Ventricular Diastole Atrial Systole Which of these is not a risk due to the effect of Atherosclerosis? Migraine Heart attack Stroke Thrombosis Select the incorrect statement regarding channel proteins. Most channel proteins are 'non-gated'. Channel proteins are water filled pores. Channel proteins have a fixed shape. They allow charged substances, usually ions, to diffuse through the membrane. By what process is a large molecule transported? Endocytosis Exocytosis Osmosis Diffusion Surface area to volume efficiency in gas exchange is best for a small organism increases with increase in size of organism inversely proportional to size of organism is not related to size of organism Oxygen moves into a cell down its concetration gradient up its concentration gradient irrespective of concentration gradient inverse of concentration gradient Select the incorrect statement regarding the structure of xylem. The only function of xylem tissue is the transportation of water in plants. Xylem vessels are made from cells joined end to end to form tubes. The cells of xylem vessels are dead. Xylem vessels have a lignified cell wall. The movement of water up through xylem vessels is by _________. Mass flow Root pressure Translocation Osmosis What are the 3 layers of a heart? a) Endocardium b) Epicardium c) Pericardium d) Myocardium a, d & c a, b & c a, d & b c, b & d The 'lub' sound of the heart is caused by the closure of which type of valves? Atrioventricular Mitral Pulmonary semilunar Aortic semilunar Which ions receive the action potential from the T-tubules? Ca2+ Na+ K+ Mg2+ Stimulation during negative feedback follows the path Hypthalamus > Anterior pituitary > Adrenal cortex Adrenal cortex > Anterior pituitary > Hypothalamus Hypthalamus > Adrenal cortex > Anterior pituitary Adrenal cortex > Hypothalamus > Anterior pituitary The small, uncovered areas of axon between Schwann cells. Nodes of Ranvier Terminal branches Synaptic knob Dendrite Which of the following is responsible for saltatory conduction in myelinated neurones? Nodes of Ranvier Axon membranes Schwann cells Voltage-gated channel proteins Which of the following is not a part of nervous system? Membrane Cell body Axon Dendrite Myelin sheath acts as An electrical insulator An electrical consuctor Signal sender from cell body to neurons Support for node of Ranvier Myelin sheath is produced By Schwann cells in PNS By Motor neurons in CNS By Sensory neurons in ANS By Axons in CNS In myelinated neurons, impulses jump from one node to the next. This is called Saltatory conduction Salt conduction Saltory conduction Ranvier conduction Which statement is true for resting and threshold phases of generation of action potential? Na-inactivation gates are open and K-gates are closed Na-activation gates are open and K-gates are closed Both Na-gates are open and K-gates are closed Both Na-gates as well as K-gates are open Which of these contain synaptic vesicles filled with neurotransmitters? Synaptic knob Synaptic cleft Synaptic divergence Synaptic effector Time is Up!