Class 10 Science Chapter 6 MCQ

Here, all these statements are correct. Hence, your answer will be option [D].

There are two adrenal glands, one on top of each kidney that make adrenaline hormone. Testes are paired glands present in males, secretes male sex hormone. Pituitary grand is present just below the brain and is unpaired. It is also called master gland as it secretes a number of hormones. Ovaries are paired glands present in females, secretes female sex hormones.

Testosterone is the male sex hormone. It regulates male accessory sex organs. It is responsible for secondary sexual characters like moustache, beard, etc. thus, increasing fertility in males.

There are two adrenal glands in our body one on top of each kidney. The adrenal glands make adrenaline hormones when we are faced with any dangerous situation, then our nervous system stimulates the adrenal glands to secrete more adrenaline hormone into our blood, then we can react according to the situation.

The person having high sugar level in blood is called a “Diabetic”. Such persons are advised to take less sugar in diet, reduce weight, exercise regularly. Persons with severe diabetes (high sugar level in blood) are treated by giving injections of insulin. Pancreas secrete the hormone insulin. Its function is to regulate blood sugar level. Deficiency of insulin causes a disease known as diabetes that is characterized by large quantities of sugar in blood and even urine. Growth hormone secreted by the pituitary gland regulates growth and development of the body.

Pituitary gland is known as “master gland” and adrenal glands are often called “glands of emergency”

The brain is broadly divided into three regions: forebrain, midbrain and hindbrain. The forebrain consists mainly of cerebrum. The midbrain does not have any further division. The hindbrain consists of 3 centres called, pons, cerebrum and medulla.

Here, all these statements are correct. Hence, your answer will be option [D].

Medulla is part of hind brain. It controls the involuntary action and regulate reflex responses. The other parts of the hind brain are cerebellum and pons.

Here, all these statements are correct. Hence, your answer will be option [D].

Synapses actually act like one-way valves. This is because the chemical substance is present on only one side of the gap. Due to this, the nerve impulses or messages through a particular set of neurons can go across only from one side which contains the chemical substance. In this way, synapses ensure that nerve impulses travel in only one direction through a particular set of neurons.

There are mainly two types of nerves in our body, “Cranial nerve” and “Spinal nerves”. The “Cranial nerves” connect all the parts in the head directly to brain. The “Spinal nerves” connect all the remaining parts of the body like muscles and skin to the spinal cord. But there is a also third type of nerves, called visceral nerves. Most of the visceral nerves connect the internal organs of the body to spinal cord though some also connect to “Brain”.

The growth of a pollen tube towards ovule is in induced by a chemical (sugar) substance secreted by the ripened stigma of flower into the style towards ovary. It is an example of chemotropism, pollen grain response to a stimulus by growing a pollen tube in downward direction, towards ovule for fertilization.

The pathway or route taken by nerve impulse in a reflex action is called reflex arc. Reflex arcs allowed “Rapid response”.

Here, all these statements are correct. Hence, your answer will be option [D].

Pancreas secrete the hormone insulin. Its function is to regulate blood sugar level. Deficiency of insulin causes a disease known as diabetes that is characterized by large quantities of sugar in blood and even urine. Growth hormone secreted by the pituitary gland regulates growth and development of the body.

A receptor is a cell (or a group of cells) in a sense organ which is sensitive to a particular type of stimulus such as light, sound, etc. The common type of receptors are: i) Photoreceptors which are present in eyes detect light. ii) Gustatory receptors which are present in tongue detect taste. Iii) Olfactory receptors which are present in nose detect smell. iv) Thermo receptors which are present in skin detect heat or cold.

Cerebellum controls the voluntary action e.g. posture. The cerebrum (part of forebrain) is the main thinking part of the brain. It coordinates the voluntary action of the body. It has different areas for performing different functions such as centres of hearing, smell, memory etc. The hindbrain consists of pons (takes part in regulating respirations), cerebellum (helps in maintaining posture and balance the body) and medulla that controls involuntary actions such as breathing etc. The midbrain controls reflex movements.

The cerebrum (part of forebrain) is the main thinking part of the brain. It coordinates the voluntary actions of the body. It has different areas for performing different functions such as centres of hearing, smell, memory, etc. The hindbrain consists of pons (takes part in regulating respiration), cerebellum (helps in maintaining posture and balance of body) and medulla that controls involuntary actions such as breathing etc. The midbrain controls reflex movements.

The pathway taken by nerve impulse in a reflex action is called the reflex arc. A reflex action is involuntary action in response to a stimulus e.g. coughing, sneezing, etc. It follows a specific pathway as given below: Stimulus → Receptors → Spinal cord → Effector → Response