Mention the types of growth regulators and give example.

1 Answer

Answer :

a) Plant growth promoters ex: Auxins, Gibberellins, cytokinins b) Plant growth inhibitors ex: Abscisic acid, Ethylene

Related questions

Description : Mention the functions of plant growth regulators.

Last Answer : Plant growth regulators promote cell division, cell enlargement/elongation and cell differentiation. They induce photropic movement of shoot system.

Description : Give reason: Phytohormones are also called growth regulators.

Last Answer : Phytohormones are organic compounds which regulate plant growth and development in plants. Hence they are called growth regulators also.

Description : Mention the common defects of the eye.

Last Answer : a) Myopic or short sight b) Hyper-metropia or long sight c) Presbyopia d) Nyctolopia or night blindness e) Cataract

Description : Which are the two fluids present in the eyeball? Mention their functions.

Last Answer : The area between the cornea and the lens is filled with a fluid called aqueous humour. The space between the cornea and the lens is filled with a thick fluid called vitreous humour. The fluids help in refraction of light rays and maintain the shape of the eye ball.

Description : Mention the two parts of the autonomic nervous system.

Last Answer : The two parts of the autonomic nervous system are: a) Sympathetic system b) para sympathetic system

Description : Mention the parts of a reflex arc.

Last Answer : The five distinct parts of a reflex arc are: a) A receptor to receive stimulus (sense organs) b) Sensory neurons to conduct the impulses from receptors to the spinal cord or the hind brain. c) ... pass the impulse to an effector. e) An effector to take necessary action in response to the stimulus.

Description : Mention the functions of adrenaline.

Last Answer : a) Adrenaline prepares the body to face emergency by producing adrenaline in excess during fear, anger, anxiety or emotional stress. b) It brings about co-ordination in heart beat, respiration and dilation of pupils.

Description : Mention the hormones secreted by adrenal medulla.

Last Answer : Adrenal medulla secretes three hormones adrenaline, nor-adrenaline and dopamine.

Description : Name the hormone secreted by the adrenal cortex. Mention its function.

Last Answer : One of the important hormones secreted by adrenal cortex is cortisone. It regulates the rate of metabolism and the concentration of salts in the blood.

Description : Where are the adrenal glands located? Mention the parts of the adrenal gland.

Last Answer : The adrenal glands are located on the upper part of each kidney. Each adrenal gland has two parts an outer cortex and inner medulla.

Description : Mention the hormones secreted by islets of Langerhans. State their function.

Last Answer : The hormones secreted by islets of Langerhans are insulin and glucagon. The functions are: Insulin promotes the conversion of glucose to glycogen for storage in liver and muscles. It is secreted ... the conversion of glycogen into glucose. It is secreted when blood glucose levels are low.

Description : Where are parathyroid glands located? Mention the hormone secreted. Mention the disorder caused due to its under secretion and over secretion. State its function.

Last Answer : Parathyroid glands are embedded in the tissues of thyroid gland. Parathyroid gland secreted a hormone called parathormone. The function of parathormone is to control the amount of calcium salts in ... cramps. Over secretion of parathormone removes calcium from the bones making them soft and spongy.

Description : What is hypothyroidism? Mention the abnormalities caused due to it.

Last Answer : Hypothyroidism is a condition in which the thyroid gland fails to produce enough thyroxin to meet the normal requirements of the body. Hypothyroidism leads to simple goitre, myxoedema and cretinism.

Description : Mention the functions of thyroxin.

Last Answer : a) Thyroxin influences the rate of metabolism. b) It increases the production of heat in the body. c) It promotes mental and physical development of the body.

Description : Mention the two ways of transferring information from one part of the body to another.

Last Answer : a) Sending chemical signals through the blood b) Sending electrical signals through the nerves.

Description : Mention the two methods of co-ordination of organ system in multi-cellular organisms.

Last Answer : Co-ordination of various organ systems in multi-cellular organisms is brought about in two ways a) Control by nervous system b) Control by endocrine system

Description : Give an example to show that sympathetic and para-sympathetic system work opposite in function.

Last Answer : Sympathetic system stimulates the pupil in the eye to dilate (open) where as parasympathetic system stimulates it to constrict (close).

Description : What are endocrine glands? Give example.

Last Answer : The glands that discharge their secretions directly into blood stream are called endocrine glands. Example: Pituitary gland, Thyroid gland

Description : What are exocrine glands? Give example.

Last Answer : The glands that discharge their secretions through the ducts to their target organs are called exocrine glands. Ex: Salivary gland, pancreas.

Description : What are phytohormones? Give example.

Last Answer : Plant hormones are also called phytohormones. They are organic compounds which are produced by tissues that regulate plant growth and development.

Description : Give an example of irritability.

Last Answer : If an earthworm is touched, it moves away from the place. Plants grow towards the light.

Description : Why is pituitary hormone referred to as ‘growth hormone’?

Last Answer : Somato Trophic Hormone which is secreted by pituitary gland regulates both physical and mental growth. Hence it is called as growth hormone.

Description : Which hormone is called growth hormone?

Last Answer : Somato Trophic Hormone is called growth hormone.

Description : What is a gland? Which are the two types of glands in our body?

Last Answer : A gland is an organ made up of cells which are specialised for secretion of particular chemical substances. The two types of glands are glands with ducts (exocrine glands) and glands without ducts (endocrine glands).

Description : Give reason: a) A strong blow on the ears is very dangerous.b) When there is severe throat infection we normally get ear pain.

Last Answer : a) A strong blow on the ears is very dangerous.As it would damage the semicircular canals and cochlea. This would lead to leakage of of fluids and sometimes even death, with ear ... pain. Throat infections affect the middle ear because eustachian tubes connect the middle ears and the throat.

Description : Give reason: A convex lens is used to correct hypermetropia.

Last Answer : In a hypermetropic eye, light is focused behind the retina. A convex lens will force it to form on the retina. Hence a convex lens is used to correct hypermetropia.

Description : Give reason: A concave lens is used to correct myopia.

Last Answer : In a myopic eye light falls too short from the retina. A concave lens forces light to fall on the retina. Hence concave lens is used to correct myopia.

Description : Give reason: a) When we suddenly enter a cinema hall, we will not be able to see any objects.b) There is no image formation at blind spot.

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Description : Give reason: Choroid is thick and rich with blood vessels

Last Answer : Choroid has a layer of blood vessels which nourishes the back of the eye.

Description : Give reason: A drunkard walks unsteadily.

Last Answer : The alcohol affects the cerebellum which is responsible for maintaining balance of the body. It is not able to control and coordinate the movement of muscles while walking.

Description : “An injury to the left cerebral hemisphere may result in paralysis of organs on the right side”. Give reason.

Last Answer : The nerves coming from the right side of the body are connected to the left cerebral hemisphere.

Description : Give reason: Person suffering from diabetes incipidus pass large quantity of dilute urine.

Last Answer : Since reabsorption of water in the kidneys has decreased

Description : Give examples show that not all responses in plants are slow.

Last Answer : Insectivorous plants like Venus fly trap responds very quickly to touch. The leaflets of touch me not plant (Mimosa Pudica) get folded immediately on touching.

Description : Give reason: Response in plants cannot be observed immediately

Last Answer : Response in plants is very slow. Hence it cannot be observed immediately.

Description : What structures enable the skin to function as a sense organ?

Last Answer : Sensory receptors are distributed all over the skin which perceive the stimuli. Touch receptors are located near the surface of the skin. Pressure receptors and pain receptors are located deep inside the skin.

Description : After relay race, Runner-A pours glucose powder into his mouth. Runner-B tastes the glucose slowly with the tip of his tongue. Whom do you think, experiences the sweetness most? Why?

Last Answer : Runner-B experiences most sweetness because the taste buds of sweetness are distributed in the front.

Description : Briefly explain the mechanism of taste.

Last Answer : Food that is eaten mixes with saliva and enters the pores of the taste buds. They chemically stimulate the sensory cells. These cells convert the chemical stimuli into electrical impulses. The electric impulses pass to the brain through the sensory neuron. The brain interprets the impulses as taste.

Description : Explain the structure of tongue.

Last Answer : The tongue is covered by a mucus membrane. It has numerous tiny sensory cells called taste buds. Taste buds are composed of a cluster of cells with receptors lying in a small depression on the surface.

Description : Explain how a pea or a button which has got into the nasal cavity be removed. OR What is the first aid to be provided to a person who got a pea or a button into the nasal cavity accidentally?

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Description : Why does food appear relatively tasteless when one has cold or running nose?

Last Answer : When you put food in your mouth, odour molecules from that food travel through the enter nose and stimulate the olfactory receptor cells at the top of your nasal cavity, If mucus in your ... receptor cells. Thus, the brain receives no signal identifying the odour Hence food eaten appears tasteless.

Description : Briefly explain the sensation of smell.

Last Answer : The molecules from the substance escapes and are carried by the inhaled air. On reaching the olfactory epithelium, they get dissolved in the mucus and stimulate the receptors. The stimulations are ... olfactory nerve to the brain. Here it interprets the impulses and gives the sensation of smell.

Description : Briefly explain the structure of the human nose.

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Last Answer : a) Hardened wax from the auditory canal should not be removed using sharp objects as they damage the eardrum. b) Loud noise must be avoided as they damage the eardrum. c) Visit a doctor if ... hearing. e) Small insects entering the ear can be removed by filling the external ear with salt water.

Description : What are these? State their function a) Pinna

Last Answer : a) Pinna: It is a cartilagenous organ covered with skin. It collects sound waves and directs them into the auditory canal. b) Tympanum: It is an obliquely placed membrane at the end of ... called Cochlea. It also contains a delicate structure called organ of corti which forms the auditory nerve.

Description : How is the ear protected?

Last Answer : a) The auditory canal has hairs at its opening to prevent tiny particles from entering the ear. b) The wax secreting cells on the inner lining of the auditory canal produces wax that traps small organisms and dust.

Description : a) What is organ of corti? b) Name the liquids that are present in inner ear.

Last Answer : a) Cochlea has delicate structures called organ of corti, which have receptors that join to form the auditory nerve. b) The entire ear is filled with a fluid called endolymph. The inner ear is surrounded by a fluid called perilymph.

Description : Describe the structure of the human ear.

Last Answer : a) The human ear is divided into three parts namely the outer ear, the middle ear and the inner ear. b) The outer ear consists of pinna, auditory canal and the tympanum. c) Pinna is ... Cochlea has delicate structures called organ of corti, which have receptors that join to form the auditory nerve.

Description : What are the precautions to be taken regarding the care of the eyes?

Last Answer : a) Do not strain your eyes by reading in dim light b) Avoid reading books during journey on roads. c) Avoid very bright light. d) Avoid watching television from a short distance. e) Avoid working on ... with cold clean water atleast twice a day. g) Consult an eye specialist in case of any problem.

Description : A person is not able to identify the colours in the traffic signal. What disease is he suffering from?

Last Answer : The disease is called colour blindness. It is a genetic disorder in which a person is unable to differentiate colours.

Description : What is Glaucoma?

Last Answer : Glaucoma is a disorder of the eye. The eyeball of a person suffering from glaucoma gradually hardens. The person sees flashes of light and coloured rings around the objects. The vision gradually decreases and leads to blindness. It occurs in persons above forty years of age.