Control and Coordination in Living Organisms
Previous years question control and coordination in living organisms
2018
Q1 The tentacles on leaves of an insectivorous plant, called sundew bend will trap the insect as soon as they come in contact with the insect’s body. This is________
Seismonasty
Thermonasty
Photonasty
Chemonasty
Answer: Seismonasty
The tentacles on leaves of an insectivorous plant, called sundew bend will trap the insect as soon as they come in contact with the insect body.
Q2 In the case of women, the Follicle Stimulating Hormone that stimulates the Graafian Follicle of the Ovary to secrete the hormone is_______
TSH
ADH
Oestrogen
ACTH
Answer: Oestrogen
In the case of women, the Follicle Stimulating Hormone that stimulates the Ovary to secrete the hormone
Q3 Which one of the following is the correct reflex arc?
Receptor → Effector → Efferent nerve→Nerve centre → Afferent nerve
Nerve centre→ Receptor →Afferent nerve- Effector→ Efferent nerve
Efferent nerve → Receptor →Afferent nerve- nerve centre-Effector
Receptor→ Afferent nerve →Nerve centre→ Efferent nerve →Effector
Answer: Receptor→ Afferent nerve →Nerve centre→ Efferent nerve →Effector is the correct reflex arc
Q4 Due to deficiency of Iodine, the synthesis of ______ hormone is hampered.
Answer: thyroid
Q5 Hypothalamus helps to maintain body balance in humans.
Answer: True.
It is responsible for maintaining your body’s internal balance, which is known as homeostasis.
Q6 Auxin helps the seed to germinate by breaking off dormancy
Answer: False
Auxin does not help in breaking seed and bud dormancy.
Q7 Name the hormones related to the following functions
(i) Regulation of sugar level in the blood
(ii) Stimulation for the secretion of hormones from the Thyroid gland
(iii) Increasing blood pressure due to anxiety
Answer: (i) Insulin and glucagon are hormones that help regulate the body’s glucose levels.
(ii) The thyroid-stimulating hormone regulates the production of thyroid hormones, thyroxine and triiodothyronine, by the thyroid gland.
(iii) Adrenaline hormone increases the blood pressure due to anxiety.
Q8 Draw a diagram of the reflex arc and label the following parts:
(a)Receptor
(b)Sensory Nerve
(c)Nerve centre
(d) Motor Nerve
Answer:
2017
Q9 Some flowers that open after sunrise and close after sunset. This is_________
Photonasty
Seismonasty
Chemonasty
Thermonasty
Answer: Photonasty
Q10 Name the hormone from the following, which a person affected with Diabetes Mellitus is unable to secrete.
Adrenaline
Insulin
Thyroxine
Testosterone
Answer: Insulin
Q11 Choose the odd one out and write it: TSH, ACTH, GTH, CSF
Answer: CSF or cerebrospinal fluid is the odd one out from TSH, ACTH, GTH and CSF.
Q12 Write one function of myelin sheath.
Answer: Myelin sheaths are cells that are part of our central nervous system and protect our nerve cells and act as an insulator which prevents short-circuiting in the neurons.
Q13 Give two differences between tropic movement and nastic movement.
Tropic Movement Nastic Movement
1)growth-dependent 1)growth independent.
2) Response in the direction of stimulus 2)Response is non directional
Q14 Write the parts of the Central Nervous System and the Peripheral Nervous System.
Answer: Central nervous system(CNS) consists of the brain and the spinal cord, while the Peripheral Nervous System(PNS) is made up of all the nerves travelling from the CNS to all the organs in your body, from the skin on your scalp to the tip of your toes.
2016
Q15 Which is the Thyroxine hormone secreting endocrine gland?
(a) Adrenal’
(b) Testis
(c) Thyroid
(d) Pancreas
Answer: (c) Thyroid
Q16 Apart from hearing, what is the other function of the human ear?
Answer: Other than hearing, the other function of the human is maintaining balance.
Q17 Which is the blood sugar controlling hormone secreted from pancreas?
Answer: Insulin is the hormone secreted by pancreas that helps in regulating the blood sugar.
Q18 Name the plant hormone that regulates tropic movement.
Answer: Auxins are the plant hormone that regulates tropic movement.
Q19 What is the one function each of “dendron” and “axon”?
Answer: Dendrites assist to convey incoming signals to the cell body. Axons are the sites where the nerve impulses are generated and passed away from the cell body to the synapse.
Q20 Why are hormones called “chemical co-ordinators”?
Answer: The prominent role of hormones is that of a messenger or a coordinator. The neurosecretory cells are specialised in the secretion of a hormone called neurohormones. They stimulate the pituitary to produce various other hormones. The changes in the level of hormone production lead to certain changes in the body. Thus, hormones as a regulator maintains the homeostasis of the body.
Q21 What is a synapse? Mention differences between ‘Afferent’ and ‘Efferent’ Nerves.
Answer: Synapse is a junction between two neurons or a neuron and a target or effector cell such as a muscle cell.
The nerves fibres are of two types – afferent fibres and efferent fibres.
The afferent nerve fibres are responsible for the transmission of impulses from the tissues to the central nervous system while the efferent nerve fibres are responsible for the transmission of impulses from the central nervous system to the concerned tissues or organs.
Q22 Define “Nerve Ganglion.” Mention two functions of the spinal cord.
Answer: Retina, the innermost layer of the eyeball is made up of three layers of nerve cells, one of which is the Ganglion cells.
Important functions of Spinal Cord are mentioned below:
- Forms a connecting link between the brain and the PNS
- Provides structural support and builds a body posture
- Facilitates flexible movements
Q23 What are the three characteristic features of hormones?
Answer:
- Chemically, hormones may be classified as either proteins or steroids.
- They are transported to the target cells/ tissue/organ through blood.
- They are destroyed after their actions.
Q24 Write the site of secretion and two functions of progesterone.
Answer: Progesterone is a steroid hormone produced by the Ovaries.
Function
- Progesterone prepares the uterus for the pregnancy after ovulation.
- It reduces the risk for miscarriage or pre-term delivery.
Q25 Describe the structural characteristics of ‘Axon’. Where is the ‘organ of corti’ located and what’s its function?
Answer: Axon is a tube-like structure that carries electrical impulse from the cell body to the axon terminals that passes the impulse to another neuron. The Axon is the longest thread on the cell body of a neuron and has an insulating and protective sheath of myelin around it.
Organ of Corti is situated in the basilar membrane of the inner ear, the organ of Corti is the organ of hearing.
Q26 From where is Adrenaline secreted in humans? Why is it called “Emergency Hormone”? Mention two functions of “Gibberellin.”
Answer: Adrenaline hormone is secreted during the time of stress or emergency by the adrenal medulla and is hence often referred to as the emergency hormone. Upon the release of adrenaline, the heart starts to beat rapidly thereby supplying a rush of oxygen to the muscles. This rush on supplying of oxygen to muscles has an impact on the lungs which leads to fast rapid breathing. The flow of blood into the skin and digestive system reduces. Muscles tend to an increased flow of blood to the skeletal system.
two main functions of Gibberellin:
- The dormancy of plant can be overcome by treating them with gibberellin.
- It speed up the process of seed germination.
Q27 Draw a neat labelled diagram of the longitudinal section of the eyeball in human and label it.
Answer:
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