Control and Coordination quiz

The gap between two neurons is called a:

Which part of the brain maintains posture and balance of the body?

The plant hormone that promotes cell division is:

The growth of a pollen tube towards the ovule is an example of:

Iodine is necessary for the synthesis of:

Which hormone is called the emergency hormone?

Involuntary actions such as blood pressure regulation, salivation and vomiting are controlled by the:

Dwarfism results from a deficiency of:

The plant hormone responsible for wilting of leaves and inhibiting growth is:

The brain is protected by a fluid-filled balloon-like structure and a bony box called the:

What is the difference between a reflex action and walking? (2 marks)

How does phototropism occur in plants? Name the hormone involved. (2 marks)

Why is the flow of signals in a synapse from the axon of one neuron to the dendrite of the next, and not the reverse? (2 marks)

Name the hormones secreted by the testes and ovaries, and state one function of each. (2 marks)

What happens at the synapse between two neurons? (2 marks)

Which signals will get disrupted in case of a spinal cord injury? (2 marks)

How do muscle cells move when they receive a nerve impulse? (2 marks)

What is the role of the hypothalamus in the secretion of growth hormone? (2 marks)

Why is the use of iodised salt advisable? (2 marks)

How does chemical coordination take place in animals? State two differences from nervous coordination. (2 marks)

In an experiment on reaction time, three trials of the ruler-drop test gave distances of 15 cm, 20 cm and 25 cm. Calculate the mean distance and use d = (1/2) g t^2, with g = 10 m/s^2, to estimate the mean reaction time. Comment on why practice may reduce the distance. (3 marks)

A stem placed horizontally bends upward by 90 degrees in 3 days, while the root bends downward by 60 degrees in the same time. Calculate the average rate of bending per day for each and name the type of tropism shown by each. (3 marks)

A survey of 400 students in a hilly district finds 60 with goitre. Calculate the percentage affected. After a year of using iodised salt, the number falls to 12. Calculate the new percentage and the percentage reduction in cases. (3 marks)

A patient's fasting blood glucose readings over a week were 160, 155, 170, 150, 165, 158 and 162 mg/dL, where the normal fasting range is about 70-100 mg/dL. Calculate the average reading. Which disease is suggested, which hormone is involved, and how is it commonly treated? (3 marks)

An adult's heart rate rises from 72 to 126 beats per minute when he is suddenly frightened. Calculate the percentage increase. Name the hormone responsible, its gland, and two other effects of this hormone that prepare the body for action. (3 marks)

Read the passage and answer the questions. Ravi accidentally touched a hot iron while ironing his clothes and immediately withdrew his hand, even before he felt the pain. Later he realised that his hand was red and painful. (i) Name this type of response and the pathway that produces it. (ii) Where in the body is this response coordinated, and why does it happen before he feels pain? (iii) Trace the path of the impulse from the receptor to the effector. (5 marks)

Read the passage and answer the questions. A gardener noticed that the shoots of potted plants kept near a window bent towards the light, while the roots grew downwards. When a pot was placed on its side, the stem began to grow upwards after a few days. (i) Name the movements shown by the shoot and the root in response to light and gravity. (ii) Which hormone is responsible for bending of the shoot? Explain how it works. (iii) Why are these called growth movements? (5 marks)

Read the passage and answer the questions. The pancreas releases insulin when blood glucose rises after a meal. When blood glucose falls, insulin secretion decreases. In some people, the pancreas does not produce enough insulin, and sugar levels in the blood remain high. (i) Name the disease caused by insufficient insulin. (ii) What type of control mechanism regulates insulin secretion? Explain briefly. (iii) Why is insulin given by injection and not by mouth? (5 marks)

Read the passage and answer the questions. A student touched the leaves of the sensitive plant (Mimosa pudica) and saw them fold up immediately. In another pot, a pea plant's tendrils had coiled around a stick over several days. (i) What causes the leaves of the sensitive plant to fold? (ii) How do the tendrils of the pea plant coil around the support? (iii) State one difference between the two movements. (5 marks)

Read the passage and answer the questions. During an inter-school race, Meera felt her heart beating fast, her breathing became rapid and her muscles seemed to have extra energy just before the start. (i) Name the hormone responsible and the gland that secretes it. (ii) List two changes this hormone causes in the body. (iii) How does the hormone reach the heart and muscles? (5 marks)

Draw a labelled diagram of the human brain. Describe the functions of the forebrain, midbrain and hindbrain, giving the role of the cerebellum, medulla and pons. Explain how the brain and spinal cord are protected. (6 marks)

What is a reflex arc? Draw a labelled diagram of the reflex arc for the knee-jerk or hot-object response, and explain why reflex arcs have evolved in animals. Distinguish between voluntary, involuntary and reflex actions with one example each. (6 marks)

Describe the plant hormones auxins, gibberellins, cytokinins and abscisic acid, stating one function of each. Draw a labelled diagram of a plant showing phototropism and geotropism, and explain how auxin causes the shoot to bend towards light. (6 marks)

Draw a labelled diagram of the human body showing the positions of the pituitary, thyroid, adrenal glands, pancreas, testes and ovaries. Name the hormone secreted by each and state one function. Explain what happens if growth hormone is secreted in excess or in deficiency during childhood. (6 marks)

Compare nervous control and hormonal control in animals in terms of speed, nature of signal, pathway, duration of effect and range of target cells. Draw a labelled diagram of a neuron and of a synapse to show how an electrical impulse is converted to a chemical signal. (6 marks)