Biology
The diagram given below represents an endocrine gland in the human body. Study the diagram and answer the following questions :
(i) Identify the endocrine gland. Where is it located?
(ii) Why is the above gland referred to as the 'Master gland'?
(iii) Name the hormone which in deficiency causes Diabetes Insipidus. How does this disorder differ from Diabetes Mellitus ?
(iv) Explain the term 'Hormone'. What is the role of Tropic hormones in the human body?
(v) Which lobe of the above gland secretes:
- Oxytocin
- ACTH
- Growth hormone
Answer
(i) Pituitary gland. The pituitary gland is a small projection which hangs from the base of the mid-brain below the hypothalamus.
(ii) The above gland is popularly called the master gland because it controls practically all other endocrine glands.
(iii) Deficiency of Antidiuretic hormone (ADH) / Vasopressin causes diabetes insipidus.
Difference between Diabetes Mellitus and Diabetes Insipidus is summarised below:
| Diabetes mellitus | Diabetes insipidus |
|---|---|
| Caused due to insufficient secretion of insulin. | Caused due to insufficient secretion of anti-diuretic hormone (ADH) / Vasopressin |
| High concentration of sugar in blood. | No sugar in urine |
(iv) Hormone is a secretion from some glandular part of the body, which is poured directly into blood and which acts on the target organs or cells of the same individual, bringing about coordination between distant parts of the body.
Tropic hormones stimulate other endocrine glands to produce their specific hormone.
(v) The lobe for the respective hormones is mentioned below:
- Oxytocin → Posterior lobe
- ACTH → Anterior lobe
- Growth hormone → Anterior lobe
Related Questions
The diagram given below represents an organ system in the human body. Study the same and answer the questions that follow:
(i) Identify the system.
(ii) Label the parts marked 2 and 4. Mention the function of part 5.
(iii) Name the structural and functional units of the part marked 1.
(iv) What is the fluid that accumulates in part 3? Which is the main nitrogenous waste present in it?
(v) Draw a neat, labelled diagram showing the longitudinal section of part 1.
State the main functions of the following :
(i) Medulla Oblongata
(ii) Cytokinins
(iii) Tears
(iv) Coronary Artery
(v) Seminal Vesicles
Given below are two stages in the evolution of man. Study them and answer the questions that follow:
(i) Identify Australopithecus and Neanderthal man from the above pictures.
(ii) Mention two characteristic features each for the two stages.
(iii) Who proposed the theory of 'Natural Selection'?
(iv) Name the organism used as an example to explain 'Industrial Melanisum'.
(v) Give two examples of vestigial organs in humans.
Given alongside is an apparatus which was set up to investigate a physiological process in plants. The setup was placed in bright sunlight. Answer the questions that follow :
(i) Name the process being studied. Define the process.
(ii) Why was the pot enclosed in a rubber sheet?
(iii) Mention two external factors which can accelerate the above process.
(iv) List two adaptations in plants to reduce the above process.
(v) Draw a neat, labelled diagram of a stomatal apparatus.