Class 10th Science Extra Questions
Science is an important subject for Class 1oth students. If you have decided to opt for Science stream then you must score good marks in CBSE Class 10th Science exam. NCERT back questions/answers alone are not enough. You need to practice exra questions too. So, today we bring to you
CBSE Class 10th Science Extra Questions
Control and Coordination Extra Questions
Q.1. What are reflex actions?
Reflex actions are those in which the response of a message comes directly from the spinal cord. The message does not go to the brain for processing. Reflex actions needs a quick response so the response message is generated from the spinal cord itself. Whenever there is a stimuli, spinal generates the correct response and send it to the effectors in the body, which takes the necessary action.
Example of Reflex action
For Ex. you accidentally touch a very hot object, so then in that case the spinal cord comes into action. The receptors present in your hands receive the signal (extremely hot object) and send it to the spinal cord for the response. Spinal cord in no time generate a message to remove your hand. In removing your hand the effectors of your hand muscles comes into action. This process is very fast and it happens in fraction of a second.
Q.2. Why should we use iodized salt in our diet?
Iodized salt contains iodine which is essential for our body. Iodine stimulates the thyroid gland and helps in its proper functioning. The release of thyroxin hormone is important for the body. Its deficiency can cause Goitre, which is an enlargement of the thyroid gland. Long time back, you must have noticed that few people in the villages or backward areas having a bulged out thyroid.
Q.3. Draw a labelled diagram of the human brain and explain the important parts and their functions in a human brain.
Human brain is the most important part of the human body. It is also called as the control centre of the body as it controls all the major functions of the human body. It is the central processing unit in the body. Muscles are attached to the brain which takes message from the brain and performs an action. Human brain is divided into three different components: The Fore brain, mid brain and the hind brain. The fore brain consists of the cerebrum, hypothalamus, and the thalamus. Mid brain consists if tectum and tegmentum. Hind brain consists of medualla, pons and the cerebellum.
Cerebellum The cerebellum coordinates actions like body balancing during swimming, cycling, and running on the track. It controls the eye movements. It handles control of voluntary movements of the body.
Cerebrum Cerebrum is the largest part of the brain which comprises of cortex and the subcortical structures. Cerebrum handles the following things: Intelligence, human memory, consciousness and your mind power. It is also responsible for problems solving, thinking, reasoning, speech etc.
It is the smallest region of the brain and controls various functions of the brain. It helps in the actions which are not under our control ex, the respiration and the cardiovascular activities. Sneezing, vomitting, and swallowing is also controlled by Medulla Oblangata only.
Q.4. What are hormones in our body? State functions of any 2 hormones.
Hormones are chemicals which are secreted by different glans of the body and control various functions of the body. It control various activities. We will discuss the fucntions of 2 hormones
Insulin: This hormone helps in the regaulation of body’s blood sugar.
Thyroxine: This hormone helps in the metabolism of fats and carbohydrates that we get from our food.
Q.5 . What are the different types of tropisms that can be seen in plants?
Tropism means movement. Plants show different type of movements.
Hydrotropism: Movement of a part of the plant towards water is known as hydrotropism.
Phototropism: Movement of a part of a plant towards light is known as Phototropism
Chemotropism: Movement of a part of a plant towards chemicals is known as chemotropism.
Geotropism: Movement of a part of a plant towards earth is known as Geotropism. Roots of the plants shows positive geotropism while the shoot or the stem shows negative geotropism.
Q.6. Name few plant hormones and briefly explain their functions.
Plants does not have a nervous system just like humans. All the functions and actions are thus controlled by hormones. Plant hormones are responsible for growth, and other responses in the plants. Some of the plant hormones are Cytokinins, Gibbererllins, Ethylene, Auxin and Abscisic acid.
- Auxin helps in the growth related movements. It helps in various tropisms like hydrotropism, geotropism, phototropism and movement of plant towards touch etc.
- Gibberellins helps in the enlargement of leaves and growth of stem.
- Cytokinins promotes cell division
- Ethylene helps in the ripening of the fruits
- Abscisic acid inhibits growth. It helps in the wilting of the the leaves, fruits and flowers.
Q.7. Name 2 endocrine glands present in the human body and explain them in short.
Thyroid gland and the Adrenal gland are 2 endocrine gland present in the human body. Lets study their functions.
- Thyroid Gland: This gland releases thyroxin hormone which regulates the metabolism of the carbohydrates, proteins and fats in the human body.
- Adrenal Gland: Adrenal gland secretes adrenaline and corticoid hormones. The corticoid hormones regulates blood pressure, heartbeat, the rate of breathing in humans. Adrenaline is secreted when we get a sense of fear. Our heart starts beating fast, rate of breathing increases. oxygen is rapidly supplied to the muscles.
Q.7. What are receptors in human body and what is their importance.
Receptor is an organ or cells which are able to respond to various stimulis like heat, light etc. Receptors are present in the whole body to receive sensations and it sends a message to spinal cord in case of reflex actions. for. Ex, if you touch a hot object accidentally the receptors present in your hands will sense it and will send a message to the spinal cord, that the object is extremely hot.
Q.8. What is Autonomic Nervous System?
Autonomic nervous sytem is responsible for involuntay actions of the body like the hearbeat, functions of blood vessels, gland and muscles etc. It is further divided into 2 parts namely. 1. Sympathetic and 2. Parasympathetic nerve fibers.
Q.9. What are the various hormones secreted by the Pituitary Gland?
The 3 hormones secreted by the Pituitary Glands are:-
- Growth Hormones
- Adrenocorticotrophic hormone
- Follicle stimulating hormones , FSH
Q.10 Explain how control and coordination takes place in the Plants.
Control and Coordination in plants takes place with the help of plant hormones. Plants do not have a brain and nervous system to control all the functions, like in the case of humans. Plants show growth, respond to various things like earth, light, touch etc. all these functions are carried out through various plant hormones. Some of the common plant hormones are Cytokinins, Gibberellins, Auxin etc
Q.11. Why brain is not involved in reflex actions?
Brain is not involved in reflex actions because these actions require fats response. The message is sent to the spinal cord for the response and in no time a response message is sent to the corresponding effectors. If the message had to be passed to the brain in case of reflex actions it would have taken more time to process and till then the stimuli would have caused damage or changes. Ex. in the case of touching a hot bowl or accidentally getting electric shock while touching a switch. Both the cases are examples of Reflex actions.
So, this was all about the Class 10th Science Extra Questions from the chapter Control and Coordination. If you have any query or doubt, feel free to ask us in the comments section below. Share the post with your friends. Stay Tuned with Careeradvice4u for more such articles.
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