The Endocrine System

Higher Level – Section A

2005 HL

3. Indicate whether the following are true (T) or false (F) by drawing a circle around T or F.

(a) Urea is formed in the kidneys. T F

(b) Motor neurons conduct impulses towards the central nervous system. T F

(c) Endocrine glands secrete hormones. T F

(d) Tendons join muscles to bones. T F

(e) The sino-atrial node (pacemaker) is located on the right side of the heart. T F

(f) A nucleus is absent from human red blood cells. T F

(g) Light is essential for the germination of seeds. T F

(h) Lenticels serve the same function as stomata. T F

(i) Parallel leaf veins are characteristic of monocotyledonous plants. T F

(j) Endosperm is a food reserve in some seeds. T F

Section A – Ordinary Level

2004 OL

1. (a) The hepatic portal vein carries blood from the alimentary canal to the

(b) A tendon joins ………………………………………… to bone.

(c) Phototropism is the growth response of a plant to

(d) Hormones are secreted by ………………..… glands.

(e) Gas exchange between a leaf and the atmosphere takes place through the

Section C – Higher Level

2005 HL

14. Answer any two of (a), (b), (c). (30,30)

(c) Answer the following questions in relation to systems of response to stimuli in the human body.

(i) The pancreas is both an exocrine gland and an endocrine gland. Explain the underlined terms.

(ii) Name a product of the endocrine portion of the pancreas and state one of its functions.

(iii) Name a disorder other than cancer for each of the following and indicate a possible cause and a means of treatment:

1. Musculoskeletal system

2. Nervous system.

2007 HL

15. Answer any two of (a), (b) and (c). (30, 30)

(b) (i) Other than the secretion of hormones, how does an endocrine gland differ from an exocrine gland?

(ii) State two ways in which hormone action differs from nerve action.

(iii) Copy the following table into your answer book and fill each of the empty boxes.

Endocrine Gland / Location / Hormone / Role of Hormone
Pancreas / Insulin
Thyroid Gland
“fighr or flight”

(iv) In the case of a named hormone give:

1. a deficiency symptom,

2. a corrective measure.

2010 HL

11. (a) (i) Name a disorder of the human nervous system.

(ii) In the case of the disorder referred to in part (i) state:

1. A possible cause.

2. A means of prevention or a treatment.

(b) (i) What is a reflex action?

(ii) Give one example of a reflex action.

(iii) Suggest an advantage of reflex actions.

(iv) The parts of the nervous system involved in a reflex action make up a reflex arc.

1.  Draw a large labelled diagram to show the structures involved in a reflex arc.

2.  Place arrows on your diagram to show the direction of impulse transmission in the reflex

arc.

(c) (i) What term is used to describe the glands that secrete hormones in the human body?

(ii) 1. Name a hormone-producing gland in the human body.

2. Where in the body is the gland located?

3. Name a hormone that this gland secretes.

4. State a role of this hormone.

5. Describe what happens if the body experiences a deficiency of this hormone.

(iii) Give two examples of the use of hormone supplements.

2011 HL

11. (a) (i) What do you understand by the term adverse external environment?

(ii) Give two ways in which plants protect themselves from adverse external environments. (9)

(b) (i) Name the group of substances in plants which control responses to external stimuli.

(ii) 1. What name is given to the regions in plants in which these substances are produced?

2. Give locations for two of these regions.

(iii) Most plant shoots are positively phototropic. Explain the underlined term.

(iv) How does the plant benefit from this response?

(v) Explain the mechanism of response by a plant to a named external stimulus.

(c) (i) What is a hormone?

(ii) State two ways in which hormones are similar to the group of substances referred to in (b)(i).

(iii) 1. What is meant by feedback in relation to hormone action?

2. Give a brief account of the feedback mechanism for a named hormone.

(iv) Describe one deficiency symptom of a named hormone.

Section C – Ordinary Level

2004 OL

15. (b) (i) What is a hormone?

(ii) Draw an outline diagram of the human body and indicate on it the location of the following hormoneproducing glands by using the following letters:

W Pituitary

X Thyroid

Y Pancreas (Islets of Langerhans)

Z Adrenals

(iii) In the case of one of the hormoneproducing glands that you have located in your diagram, state:

1. the gland and a hormone that it produces.

2. a function of this hormone.

3. a deficiency symptom of this hormone.

(iv) State one way in which hormone action differs from nerve action.

14. Answer any two of (a), (b) or (c) (30,30)

(b) (i) The diagram shows some parts of the human endocrine system.

Name the glands labelled A and B.

(ii) Name any one hormone produced by the body.

(iii) Give a deficiency symptom of the hormone named

in (ii) above.

(iv) Give one example of the use of hormone supplements.

(v) The central nervous system is made up of two main parts.

Name each part.

(vi) Name a disorder of the nervous system.

Give one cause of the disorder and suggest a means of

treating the disorder.