Coordination (LAQs)

Biology | 5. Coordination – LAQs:
Welcome to LAQs in Chapter 5: Coordination. This page contains the most Important FAQs for Long Answer Questions in this Chapter. Each answer is provided in simple English, with a Telugu explanation, and formatted according to the exam style. This will support your preparation and help you secure top marks in your exams.

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LAQ-1 : Describe the structure of spinal cord.

Introduction

The spinal cord is a crucial component of the human body’s nervous system. It acts as a conduit between the brain and the rest of the body, facilitating the transmission of messages and control of reflexes.

Location of the Spinal Cord

The spinal cord resides within the vertebral column, a series of bones constituting the backbone. It originates from the medulla oblongata at the base of the brain and extends down to the lower back, ending near the first lumbar vertebra.

Shape and Composition

The spinal cord is cylindrical in shape. It comprises an outer layer of white matter and a central region of grey matter, contrasting with the brain’s structure.

White Matter

The white matter, forming the spinal cord’s outer layer, derives its color from the presence of myelinated axons—nerve fibers sheathed in a fatty substance. These axons project from both sides of the vertebral column.

Grey Matter

Centrally located, the grey matter lacks the myelin coating of the white matter, giving it a grey appearance. It contains the nerve cells or neurons.

Function and Importance

The spinal cord’s role extends beyond mere message transmission between the brain and body; it is pivotal in reflex actions. These are swift, automatic responses to stimuli, such as withdrawing a hand from a hot surface. The spinal cord enables these rapid reactions, bypassing the need for brain processing.

Summary

Nestled within the vertebral column, the spinal cord is a cylindrical entity comprising an outer white matter and a central grey matter. It plays a vital role in message transmission and reflex action control, offering a fascinating glimpse into the human body’s intricate mechanisms. This essential knowledge equips students for their exams and provides a captivating overview of the spinal cord’s function for a broader audience.

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LAQ-2 : Analyze the following information and answer the questions.

Hormones	Uses
Auxins	Cell elongation, differentiation of shoots and roots
Abscisic acid	Closing of stomata, seed dormancy
Ethylene	Ripening of fruit
Cytokinins	Promote cell division, promotion of sprouting of lateral buds, delaying the ageing in leaves, opening of stomata.

OR

Analyze the information given below. Write answers to the questions given below.

Hormones	Uses
Auxins	Cell elongation, differentiation of shoots and roots.
Cytokinins	Promote cell division, delaying the ageing in leaves, opening of stomata.
Gibberellins	Germination of seeds, sprouting of buds, elongation of stem, stimulation of flowering, development of seedless fruits, breaking the dormancy in seeds and buds.
Abscisic acid	Closing of stomata, seed dormancy, promoting ageing of leaves
Ethylene	Ripening of fruit

1. What do we call the hormones present in plants? Name any two of them.
   The hormones present in plants are known as phytohormones. Two examples are auxins and cytokinins.
2. Name the hormones which help in the growth of plants?
   Hormones that assist in plant growth include auxins, gibberellins, and cytokinins.
3. Which hormone promotes the opening of stomata, and which hormone acts against this?
   Cytokinins promote the opening of stomata, while abscisic acid acts to close the stomata.
4. Write the functions of Abscisic acid?
   Abscisic acid is responsible for closing stomata, inducing seed dormancy, and potentially promoting the aging of leaves.

OR

1. What are phytohormones? Write the names of two phytohormones.
   Phytohormones are hormones present in plants. Two examples are auxins and gibberellins.
2. Which hormone is responsible for the closing of stomata, and which hormone acts against it?
   Abscisic acid is responsible for closing stomata, while cytokinins promote their opening.
3. What are the functions performed by Abscisic acid?
   Abscisic acid helps in closing stomata, induces seed dormancy, and may promote leaf aging.
4. Which hormones help in plant growth?
   Hormones that aid in plant growth include auxins, gibberellins, and cytokinins.

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LAQ-3: Analyse the table and answer the following questions.

S.No.	Part of Brain	Functions
1.	Cerebrum	Mental abilities, memory, speech
2.	Dlencephalon	Sensory impulse, emotional impulse muscular activities
3.	Mid brain	Reflexes of sight and hearing equilibrium
4.	Cerebellum	Equilibrium
5.	Medulla oblongata	Respiratory, cardiac centres, blood pressure

1. Which part of the brain recollects childhood incidents?
   The cerebrum is responsible for recollecting childhood incidents, as it handles memory.
2. Write two parts of the hindbrain.
   The two parts of the hindbrain are the cerebellum and the medulla oblongata.
3. Name the part of the brain that may not function properly in a drunken person.
   The cerebellum may not function properly in a drunken person, affecting balance and coordination.
4. Name the part of the brain that controls involuntary actions.
   The medulla oblongata controls involuntary actions such as respiratory and cardiac functions, and regulates blood pressure.

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LAQ-4 : Explain the phytohormone which controls growth in plants.

Introduction

Phytohormones, or plant hormones, are critical chemicals that play a vital role in controlling and coordinating the growth and development of plants. These hormones respond to environmental stimuli and ensure efficient plant functioning. This article explores the various types of phytohormones and their specific roles.

Auxins

1. Auxins’ Role in Growth:
   Auxins play a critical role in growth, being essential for cell elongation and differentiation in both shoots and roots.
2. Uses of Phytohormones in Plants:
   These phytohormones are pivotal in controlling the direction of growth and assisting in the formation of various plant structures, underlining their importance in plant development and morphology.

Cytokinins

1. Promotion of Cell Division by Cytokinins:
   Cytokinins are vital for promoting cell division, a fundamental aspect of plant growth.
2. Diverse Uses in Plant Development:
   They play a significant role in the sprouting of lateral buds, delaying the aging of leaves, opening stomata (tiny pores on leaf surfaces), and enhancing overall plant growth and vitality, highlighting their crucial role in various facets of plant development and health.

Gibberellins

1. Gibberellins in Seed Germination and Plant Growth:
   Gibberellins are instrumental in assisting seed germination, bud sprouting, and stem elongation, playing a key role in the early stages of plant growth.
2. Uses of Gibberellins in Plant Development:
   These hormones actively stimulate flowering, aid in the development of seedless fruits, and are crucial in breaking the dormancy in seeds and buds, thereby significantly facilitating plant growth and development.

Abscisic Acid (ABA)

1. Role in Managing Plant Stress Responses:
   Abscisic Acid is significant in managing plant stress responses, playing a crucial role in growth regulation under challenging conditions.
2. Functional Uses in Plant Adaptation:
   Its uses include involvement in closing stomata to minimize water loss, maintaining seed dormancy, and promoting leaf aging, highlighting its essential function in the adaptation and survival of plants.

Ethylene

1. Control of Fruit Ripening by Ethylene:
   Ethylene, a gaseous hormone, predominantly controls the ripening of fruits, playing a vital role in their growth and development.
2. Commercial Uses of Ethylene:
   In terms of its uses, ethylene is widely utilized in commercial settings to regulate the ripening process of many fruits, ensuring they ripen at the appropriate time and thereby maintaining their quality and market value.

Summary

Phytohormones are essential regulators of plant growth, with each type having specific roles and applications. From directing growth and developing plant parts (Auxins) to encouraging cell division (Cytokinins), aiding in seed germination (Gibberellins), managing stress responses (Abscisic Acid), and ripening fruits (Ethylene), these hormones are vital for the healthy development and functioning of plants. A thorough understanding of these hormones is fundamental for students of botany and those interested in plant growth and care.

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LAQ-5 : Analyse the following information and answer the questions.

Organ	List-1 : Effect of Nervous System	List-2 : Effect of Nervous System
Eye	Dialates pupil	Constricts pupil
Mouth	Inhibits salivation	Stimulates salivation
Lungs	Relaxes bronchi	Constrict bronchi
Heart	Accelerates heart beat	Heart beat to normalcy
Blood pressure	Increase blood pressure	Decrease blood pressure
Pancreas	Inhibits pancreas activity	Stimulates pancreas activity

1. Write two functions of the Sympathetic Nervous System.
   The Sympathetic Nervous System dilates pupils and accelerates heartbeat.
2. Name two organs influenced by the Parasympathetic Nervous System.
   The Parasympathetic Nervous System influences the heart and the pancreas.
3. Name the nervous system mentioned in the table that increases blood pressure.
   The Sympathetic Nervous System increases blood pressure.
4. What systems constitute the Autonomic Nervous System?
   The Autonomic Nervous System comprises both the Sympathetic and Parasympathetic Nervous Systems.

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LAQ-6 : Karthik is suffering from excess sugar in urine and varun is suffering from repeated dilute urination. What are the reasons for these disease? Explain.

Introduction

The medical conditions that Karthik and Varun are experiencing are related to two different types of diabetes, each distinct in their causes and symptoms. This explanation aims to clarify these two diseases and the reasons behind them.

Diabetes Mellitus: Karthik’s Condition

1. Characteristics of Diabetes Mellitus:
   Diabetes Mellitus, commonly known as sugar diabetes, is characterized by an excess of sugar in both the blood and urine.
2. Cause: Insulin Deficiency:
   This condition is primarily caused by a deficiency of insulin, a hormone produced by the pancreas.
3. Role of Insulin in Blood Sugar Regulation:
   Insulin plays a crucial role in regulating blood sugar levels by aiding glucose (sugar) entry into cells for energy.
4. Consequences of Insulin Insufficiency:
   When insulin is insufficient, blood sugar levels become elevated, leading to excess sugar being filtered into the urine, which is the reason for the presence of sugar in Karthik’s urine.

Diabetes Insipidus: Varun’s Condition

1. Characteristics of Diabetes Insipidus:
   Diabetes Insipidus is characterized by frequent urination of large volumes of dilute urine.
2. Primary Cause: Vasopressin Deficiency:
   The primary cause of this condition is a deficiency of vasopressin, also known as antidiuretic hormone (ADH).
3. Role of Vasopressin in Water Balance:
   Vasopressin is crucial for maintaining the osmotic concentration of body fluids, thereby controlling the body’s water balance.
4. Consequences of Vasopressin Insufficiency:
   When vasopressin is insufficient, the kidneys struggle to conserve water, resulting in frequent urination and the production of diluted urine, as observed in Varun’s case.

Summary

Diabetes Mellitus and Diabetes Insipidus are two distinct medical conditions affecting the urinary system. Karthik’s excess sugar in the urine is due to Diabetes Mellitus, caused by a lack of insulin. In contrast, Varun’s repeated dilute urination is due to Diabetes Insipidus, caused by a deficiency of vasopressin. Despite sharing the common name “diabetes,” these two types have different causes and effects, reflecting their distinct impacts on the body’s regulation of sugar and water balance.