Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis

Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis English Medium

Select the correct answer.

Question 1.
Location of adrenal gland
a. Below thalamus
b. In the scrotum
c. Above the kidneys
d. Just below the sternum
c. Above the kidneys

Question 2.
The normal level of glucose in blood
a. 80 – 130 mg/100 ml
b. 70 – 110 mg/100 ml
c. 9-11 mg/100 ml
d. 60 – 100 mg/100 ml
b. 70-110 mg/100 ml

Question 3.
The ‘Youth hormone ’ is
a. Thymosin
b. Epinephrine
c. Melatonin
d. Oxytocin
a. Thymosin

Question 4.
The hormone in gaseous form
a. Auxin
b. Ethylene
c. Gibberellins
d. Cytokinin
b. Ethylene

Question 5.
Fill up the blanks by observing the relationship between the first pair.
a. Calcium : Calcitonin
Glucose : …………………
b. Breaks up stored food : Gibberellins. Promoting the growth of terminal buds : ………………….
c. Norepinephrine : Medulla Aldosterone : ………………..
a. Insulin
b. Auxin
c. Cortex

Question 6.
Find out the odd one and note down the common features of others.
a. Cortisol, Aldosterone, Epinephrine,Sex hormones.
c. Cretinism, Gigantism, Dwarfism, Acromegaly
a. Epinephrine
Others are produced by the cortex of adrenal glands.
b. ADH
Others are tropic hormones.
c. Cretinism
Others are related to the production of somatotropin.

Question 7.
The quantity of urine excreted by a person in different seasons is given below. Analyze it and answer the following questions.
Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis 1
a. Which is the coldest season?
b. Which hormone is responsible for the variation in quantity of urine?
c. How does this hormone regulate the water level of the body?
a. Season 3
b. Vasopressin (ADH)
c. If the production of vasopressin decreases, the reabsorption of water in kidneys decreases. As a result. the quantity of water level in urine increases.

Question 8.
Given below is an incomplete table showing reproduction related both’ changes, controlling hormones, their glands and functions. Fill the missing gaps.

Hormone Gland Function
Progesterone a Maintenance of embryo
b Ovary Growth of sex organs
Testosterone C d
Prolactin e f
g h Facilitating child

a. Ovary
b. Oestrogen
c. Testis
d. Sperm production, controls secondary sexual characters in males such as change in voice, growth of hair, etc.
e. Pituitary gland
f. Production of milk
g. Oxytocin
h. Hypothalamus

Question 9.
All hormones do not act upon all cells. Why?
Hormones reach every cell in the body as they are transported by blood. But each hormone acts only upon those cells which have specific receptors. The cells which are acted upon by hormones are their target cells

Question 10.
What are the functions of thyroxine? How do the abnormalities in the production of thyroxine affect the body?

  • Functions of thyroxine – Raises the rate of metabolism, accelerates the growth and development of the brain in the foetal stage and infancy, increases energy production, regulates growth in children.
  • The deficiency of thyroxine during the foetal stage or infancy – cretinism.
  • Lack of thyroxine in adults – myxoedema.
  • The condition in which all life activities controlled by thyroxine are accelerated due to the excessive production of thyroxine – hyperthyroidism.

Question 11.
Select the answers for the statements from the box given below.
Auxin, Gibberellins, Ethylene, Cytokinin,
Abscisic acid
a. Helps in the ripening of fruits.
b. Helps to sustain the plant in adverse conditions.
c. Promotes cell growth and differentiation.
d. Breaks up stored food.
e. Cell growth, cell elongation, promoting the growth of terminal buds
a. Ethylene
b. Abscisic acid
c. Cytokinin
d. Gibberellins
e. Auxin

Question 12.
Identify the disease. Write the reason for this.
Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis 2
Iodine is essential for the production of thyroxine. The production of thyroxine is obstructed in the absence of iodine. In an attempt to produce more thyroxine, the thyroid gland enlarges.

Question 13.
Find out the peculiarities of column A and rearrange columns B and C.

Oxytocin Parathyroid Prevents the rise of calcium
Prolactin Thyroid Facilitates lactation
Parathormone Hypothalamus Production of milk
Pituitary Prevents the lowering of calcium


  • Oxytocin – Hypothalamus – Facilitates lactation
  • Prolactin – Pituitary – Production of milk
  • Parathormone – Parathyroid – Prevents the lowering of calcium

Question 14.
Hints related to a patient are given below.
Analyze and answer the questions given below.

  • The blood glucose level is more than normal level.
  • Always tired
  • The production of insulin is normal in his body.

a. Identify the disease.
b. Write the reason for this disease.
c. How is the disease related to tiredness?
a. Diabetes
b. Malfunctioning of insulin.
c. Insulin enhances cellular uptake of glucose molecules. If the insulin is malfunctioned, it cannot perform this function. The glucose level in cell decreases leading to low energy production. So he feels tired.

Question 15.
Observe the illustration.
Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis 3
Complate A,B,C,D,E
A. Cortex
B. Norepinephrine
C. Aldosterone
D. Sex hormones
E. Cortisol

Question 16.
“Isn’t this merely a storage and distribution centre? Is it sensible to call this a gland?” This is a doubt raised by Hari, pointing to a particular portion of a gland in the picture of the brain.
a. Which part of which gland may be the basis of Hari’s doubt?
b. Why does Hari have such a doubt? Is his doubt genuine? Why?
a. Pituitary – Posterior lobe
b. Sensible. The hormone produced by hypothalamus is stored and released from here. The posterior lobe of pituitary itself does not produce hormone.

Question 17.
Use of artificial plant hormones contributed a lot to the progress of the agricultural sector.
Justify this statement.
(Hints: Artificial gibberllins, artificial abscisic acid, Ethylene)
Artificial gibberllins – It is used for increasing fruit size in grapes and apple and also for preventing ripening of fruits to assist marketing.

Artificial abscisic acid – It is used for harvesting fruits at the same time.
Ethylene- Ethylene is used for the flowering of pineapple plants at a time and for the ripening of tomato, lemon, orange, etc. Ethyphon, a chemical which is available in liquid form, gets transformed into ethylene, when used in rubber trees and it increases the production of latex.

Question 18.
Arrange columns B. C according to the data given in column A.

Diabetes mellitus Excessive production of somatotropin. Low metabolic rate, hypertension. sleeplessness
Acromegaly Lack of thyroxine Increased appetite and thirst and frequent urination.
Cretinism Decreased production of insulin. High metabolic rate, rise in body temperature.
Production of somatotropin decreases Growth of the bones on face, jaws and fingers.


Diabetes mellittus Decreased production of insulin. Increased appetite and thirst and frequent urination.
Acromegaly Excessive production of somatotropin. Growth of the bones on face, jaws and fingers.
Cretinism Lack of thyroxine Low metabolic rate, hypertension, sleeplessness.

Question 19.
Observe the graph and answer the questions given below.
Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis 4
a. Who has the normal level of calcium in blood?
b. Name the hormones which help to regulate the blood calcium level in other persons. Explain the action of these hormones.
a. Mini
Raju- The level of calcium in blood is more.
The calcitonin secreted by thyroid gland helps in maintaining the level of calcium in blood by depositing the excess calcium in bones and by preventing the mixing of calcium with blood from the bones.

Jose – The level of calcium in blood is less. The parathormone secreted by parathyroid gland helps in maintaining the level of calcium in blood by the reabsorption of calcium in the blood from kidneys and also prevents the deposition of calcium in bones.

Question 20.
Some hormones are given below. Make them into four pairs. Give reasons for pairing.
Oxytocin, Thyroxine, Insulin, Epinephrine, Vasopressin. Glucagon, Cortisol, Calcitonin

  • Oxytocin, Vasopressin – Secreted by hypothalamus
  • Thyroxine, Calcitonin -Secreted by thyroid gland
  • Insulin, Glucagon – Secreted by pancreas.
  • Epinephrine, Cortisol – Secreted by adrenal gland

Question 21.
Manu rubbed strongly across the path of the row of moving ants. All the ants moved in different directions immediately.
a. Which is the substance responsible for this?
b. Write another use of this substance.
a. Pheromones
b. Pheromones help in attracting mates, informing the availability of food, determining the path of travel, informing about dangers, etc.

Question 22.
Analyze the illustration and answer the questions.
Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis 5
a. What is indicated by A (Write the lobe also)?
b. ‘A’ produces the hormones of same type. Do you agree with this statement ? Why?
a. The anterior lobe of pituitary.
b. No. It produces tropic hormones (TSR. ACTh,GTH, STH) and prolactin.

Question 23.
Arrange columns B and C according to the data given in column A.

Vasopressin Adrenal On either side of trachea, just below the larynx
Cortisol Pituitary Just below the sternum
Thymosin Hypothalamus Above kidneys
Thymus Below thalamus


Vasopressin Hypothalamus Below thalamus
Cortisol Adrenal Above kidneys
Thymosin Thymus Just below the sternum

Question 24.
Arrange the statements suitably ¡n the table given below
a. Low metabolic rate.
b. High metabolic rate
c. Emotional imbalance
d. Increase in body weight
e. Oedema
f. Excessive sweating

Hypothyroidism Hyperthyroidism







Hypothyroidism Hyperthyroidism
Low metabolic rate High metabolic rate
Increase in body weight Emotional imbalance
Oedema Excessive sweating

Question 25.
Observe the illustration and answer the question given below
Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis 6
a. Identify the hormones indicated by i, ii, iii, iv
b. Write the functions of prolactin and oxytocin.
c. Name the condilion caused by the decreased production of somatotropin?
a. i. Vasopressin
ii. Oxytocin
iii. Tropic hormones
iv. Somatotropin

  • Prolactin – Production of milk
  • Oxytocin – Facilitates child birth by stimulating the contraction of smooth muscles in the uterine wall, facilitates lactation,

c. Dwarfism

Question 26.
Some statements related to endocrine system are given below.
A. Hormones are the secretions of endocrine glands.
B. Hormones are transported through lymph.
C. Hormones are transported through blood.
D. All the hormones produced by the endocrine glands are proteins.
a. Choose the correct statement.
b. Imagine that a particular hormone is not entering a particular cell. What may be the reason?
a. A.Hormones are the secretions of endocrine glands.
C.Hormones are transported through blood.

b. Receptors of that hormones are not in the cell.

Question 27.
Case sheets of two patients are given below. Analyse them and answer the questions.

Case -1 Case -2
Age – 4 yrs Age – 42 yrs
Mental retardation High metabolic rate
Stunted growth Increased heart beat
Emotional imbalance

a. Which are the diseases whose symptoms are indicated above?
b. Write the reasons for the diseases.
a. Case – 1 Cretinism
Case – 2 Hyperthyroidism

b. Case – 1
Deficiency of thyroxine during foetal stage and infancy.
Case – 2
Excessive production of thyroxine.

Question 28.
Observe the diagram of the endocrine gland given below and answer the questions.
Kerala SSLC Biology Chapter 3 Questions Chemical Messages for Homeostasis 7
a. Name the parts indicated as A and B.
b. Name the hormones synthesized by A. Explain their action.
a. A-Medulla B – Cortex
b. Epinephrine, Norepinephrine
Epinephrine – Helps to tide over emergency situations.
Norepinephrine – acts along with epinephrine.

Question 29.
Analyse the statements given below and write the reason.
a. Oxytocin is injected in pregnant women during child birth (delivery).
b. Feels sleepy during night, wakes up when day breaks.
a. Facilitates child birth by stimulating the contraction of smooth muscles in the uterine wall.
b. When the level of melatonin increases at night, we feel sleepy. We wake up when the level of melatonin decreases during the day.

Question 30.
A farmer named Balan cultivated oranges in his orchard. Now the trees are full of oranges. The price of oranges is Rs. 80/kg.
A. This farmer wants to harvest all fruits together.
B. Ripen them together.
a. Suggest two artificial plant hormones to satisfy the A, B needs of the farmer.
b. Uncontrolled use of plant hormones must
be controlled. Evaluate this statement.
a. A – Abscisic acid.
B – Ethylene

  • Control uncontrolled use.
  • Environmental issues.
  • Health issues.

Question 31.
Indicators related to the endocrine glands are given below. Analyse them and answer the questions.

  • Situated just below the sternum.
  • Active during infancy.

But constricts at puberty.
a. Name this endocrine gland.
b. Which is the hormone synthesised by this gland?
c. Write the function of this hormone.
a. Thymus gland
b. Thymosin
c. Controls the activities and maturation of lymphocytes which help to impart immunity.

Kerala SSLC Biology Chapter Wise Questions and Answers