CBSE Class 10 Science Control and Coordination Assignment Set D

CCT BASED QUESTIONS

A brain is displayed at the Allen Institute for Brain Science. The human brain is a 3- pound (1.4-kilogram) mass of jelly-like fats and tissues—yet it's the most complex of all known living structures The human brain is more complex than any other known structure in the universe. Weighing in at three pounds, on average, this spongy mass of fat and protein is made up of two overarching types of cells—called glia and neurons— and it contains many billions of each. Neurons are notable for their branch-like projections called axons and dendrites, which gather and transmit electrochemical signals. Different types of glial cells provide physical protection to neurons and help keep them, and the brain, healthy. Together, this complex network of cells gives rise to every aspect of our shared humanity. We could not breathe, play, love, or remember without the brain.

Question. Animals such as elephants, dolphins, and whales actually have larger brains, but humans have the most developed cerebrum. It's packed to capacity inside our skulls and is highly folded. Why our brain is highly folded?
Answer : To increase the surface area of the brain to receive sensory impulses from various receptors, interpret the sensory information with the information that is stored in the brain and respond accordingly

Question. Which among this is not a function of cerebrum?
a) speech
b) Learning
c) Posture
d) Emotion
Answer : C

Question. Which among these protects our brain?
a) Neurotransmitter
b) Cerebrospinal fluid
c) Meninges
d) Grey matter
i) a, b & c
ii) b & c
iii) c & d
iv) b,c&d
Answer : B

Question. Ram was studying in his room. Suddenly he smells something burning and sees smoke in the room. He rushes out of the room immediately. Was Ram’s action voluntary or involuntary? Why?
Answer : 4. Ram’s action was voluntary because rushing out of the room was under conscious control. The smoke and smell were perceived by the receptor and sensor and signals are sent to the brain. The brain then sent the signals to effector organs.

Very Short Answer type Questlons

Question. If we happen to touch a hot object unknowingly, we immediately pull back our hand. What is this type of action known as ?
Answer : Reflex action

Question. Which part of the brain maintains posture and balance of the body ?
Answer : The cerebellum of the brain maintains posture and balance of the body.

Question. State one function each of cerebellum and pons.
Answer : The pons participates in regulating respiration. The cerebellum helps in maintaining balance and posture of the body.

Question. Name one hormone secreted by the pituitary gland.
Answer : Antidiuretic hormone (ADH, or vasopressin)

Question. Where are hormones made in the human body ?
Answer : Endocrine glands

Question. What is the name of the system of glands which produces hormones ?
Answer : Endocrine system

Question. Name the three components of a neuron (or nerve cell).
Answer : The three components of a neuron (or a nerve cell) are the cell body, the dendrites and the axon.

Question. (a) What are the short fibres of a neuron known as ?
(b) What is the long fibre of a neuron known as ?
Answer : (a) The short fibres of a neuron are known as the dendrites.
(b) The long fibre of a neuron is known as the axon.

Question. Name the most important part of the human brain.
Answer : The cerebrum (forebrain) is the most important part of the human brain.

Question. Which gland secretes the growth hormone ?
Answer : The pituitary gland

Question. Name the hormones secreted by (a) testes, and (b) ovaries
Answer : (a) The testes secrete testosterone also known as male sex hormone.
(b) The ovaries secrete oestrogen and progesterone also known as female sex hormone.

Question. Name the two systems of control and coordination in higher animals.
Answer : The two systems of control and coordination in higher animals are the nervous system and the endocrine system.

Question. What are the two parts of the vertebrate nervous system ?
Answer : The two parts of the vertebrate nervous system are the central nervous system and the peripheral nervous system.

Question. What are the scientific names for the following receptors in animals ?
(a) receptors for light (b) receptors for heat (c) receptors for sound
(d) receptors for smell (e) receptors for taste
Answer : The scientific names for the following receptors in animals are-
(a) receptors for light - Photoreceptor.
(b) receptors for heat - Thermoreceptor.
(c) receptors for sound - Phonoreceptor.
(d) receptors for smell - Olfactory receptors.
(e) receptors for taste - Gustatory receptors. 

Question. Name the disease caused by the deficiency
Answer : Scurvy: It is caused by a deficiency of vitamin C.
Rickets: It is caused by the deficiency of vitamin D.
Anaemia: It is caused by the deficiency of iron.
Goitre: It is caused by the deficiency of iodine

Question. Name the disease caused by the deficiency of thyroxine hormone in the body.
Answer : Goitre

Question. Which halogen element is necessary for the making of thyroxine hormone by the thyroid gland ?
Answer : Iodine

Question. Why are some patients of diabetes treated by giving injections of insulin ?
Answer : 1. Insulin is a hormone secreted by the pancreas that regulates the sugar level in the blood.
2. When this hormone is not synthesised in proper amount then the sugar level in the blood rises, then the person is said to be suffering from diabetes. This is the reason why diabetic patients are treated by giving injections of insulin.

Question. What is the name of in-built ‘arrangement’ in our body which controls the timing and amount of hormones released by various endocrine glands in the body ?
Answer : Feedback mechanism

Question. Name one gland each :
(a) which acts only as an endocrine gland.
(b) which acts only as an exocrine gland.
(c) which acts both as an endocrine gland as well as an exocrine gland.
Answer : (a) Thyroid is a large ductless gland present in the neck, acts only as an endocrine gland.
(b) Salivary gland present in and around the mouth and neck, acts only as an exocrine gland.
(c) Pancreas, an organ located in the abdomen, acts both as an endocrine gland and an exocrine gland.

Question. What part does the diet play in helping us to have a healthy thyroid gland ?
Answer : Diet provides iodine for making thyroxine hormone which keeps the thyroid gland healthy

Question. If sugar is detected in the urine of a person, name the disease he is suffering from.
Answer : Retina

Question. Name two parts of the body which contain receptors of chemical stimuli.
Answer : Nose and Tongue

Question. Which part of the eye contains cells which are sensitive to light ?
Answer : Retina

Question. What are the two main communications systems in an animal’s body ?
Answer : The nervous system and the endocrine system are the two main communication systems in an animal body.

Question. Which one term in each of the following includes the other three ?
(a) thyroid, ductless gland, thymus, pituitary, ovary
(b) adrenalin, insulin, hormone, thyroxine, estrogen
Answer : (a) ductless gland (b) hormone

Question. Which parts of the body form the central nervous system ?
Answer : The central nervous system is made up of the brain and spinal cord.
The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.

Question. Give three examples of reflex actions.
Answer : Coughing, yawning and blinking of eyes are examples of reflex actions.

Question. Why do you need iodine in your diet ?
Answer : Iodine is needed in our diet because it helps the thyroid gland in making thyroxine hormone.

Question. State whether coughing is a voluntary action or reflex action.
Answer : Reflex actions are those actions which we do without thinking to protect ourselves. Coughing is a reflex action as it clears our windpipe.