Chapter-6 Tissues

Explanation:

A tissue is a group of cells that perform a specific function or work together to achieve a particular task within an organism. In multicellular organisms, cells with similar structures and functions often aggregate to form tissues. Tissues can be found in various organs throughout the body and can be categorized into four main types: epithelial tissue, connective tissue, muscle tissue, and nervous tissue. Each type of tissue has its own unique structure and function that allows it to contribute to the overall health and functioning of the organism.

Explanation:

Tissues are essential in multicellular organisms for several reasons:

1. Specialization: Cells within a tissue are specialized to perform a specific function, and by working together in a tissue, they can perform that function more efficiently and effectively than they could individually.

2. Organization: Tissues help to organize the cells in multicellular organisms, enabling them to work together in a coordinated manner to carry out various tasks and processes.

3. Adaptation: Tissues allow organisms to adapt to their environment by developing specialized structures that enable them to perform tasks such as sensing light, digesting food, or circulating oxygen.

4. Protection: Tissues provide protection to the body by forming barriers that prevent the entry of harmful substances or organisms.

5. Repair: Tissues also play a critical role in repairing damaged tissues and healing injuries.

Overall, the utility of tissues in multicellular organisms is to enable efficient and effective functioning of the organism as a whole, allowing it to survive and thrive in its environment.

Explanation:

There are three types of simple tissues:

1. Parenchyma: Parenchyma is the most common type of simple tissue in plants. It is composed of thin-walled, living cells that are involved in various functions such as photosynthesis, storage, and secretion.

2. Collenchyma: Collenchyma is a type of simple tissue that provides mechanical support to the plant. It is made up of elongated cells with thickened cell walls that provide strength and flexibility.

3. Sclerenchyma: Sclerenchyma is a type of simple tissue that provides structural support to the plant. It is composed of thick-walled, dead cells with lignified cell walls that are extremely hard and durable. Sclerenchyma cells are often found in regions of the plant that require additional support, such as the stems and roots.

Explanation:

Apical meristem is found at the tips of roots and shoots of plants. It is a region of actively dividing cells that is responsible for the growth in length of the plant.

In roots, the apical meristem is located at the tip of the root, while in shoots, it is located at the tip of the stem.

The apical meristem is responsible for producing new cells that differentiate into various types of tissues, including the three types of simple tissues (parenchyma, collenchyma, and sclerenchyma) as well as the various types of complex tissues that make up the plant's organs.

Explanation:

The husk of a coconut is made up of a type of tissue called the sclerenchymatous tissue, which is a part of the fruit's exocarp or outermost layer. These cells of this tissue work together to provide mechanical support as it makes the plant to become hard and stiff and protect the seed inside.

The cells are dead of this tissue and their cell walls are thick because of the existence of lignin.

Explanation:

The phloem tissue is composed of four main types of specialized cells:

1. Sieve tube elements: These are elongated, tube-like cells that form the main conducting elements of the phloem. They are arranged end-to-end to form long, continuous tubes that transport organic compounds from source to sink organs.

2. Companion cells: Companion cells are closely associated with the sieve tube elements and provide metabolic support to the phloem. They help to load and unload organic compounds into and out of the sieve tube elements and provide energy for phloem transport.

3. Phloem fibers: Phloem fibers are elongated, sclerenchyma cells that provide mechanical support to the phloem tissue.

4. Phloem parenchyma: Phloem parenchyma cells are specialized parenchyma cells that provide additional support to the phloem tissue and store reserve carbohydrates and other organic compounds.

Explanation:

The tissue responsible for movement in our body is called muscle tissue. Muscle tissue is composed of specialized cells called muscle fibers that are capable of contracting and relaxing in response to nerve impulses.

The other tissue responsible for movement is called nervous tissue which makes up the nervous system which in turn is responsible for receiving and processing sensory information from the environment, coordinating and controlling our movement.

Explanation: 

Neurons come in different shapes and sizes, but they all have a similar basic structure. Some neurons are small and have short, unmyelinated axons, while others are large and have long, myelinated axons. The shape and size of a neuron depends on its function and location in the nervous system.

Explanation:

Cardiac muscle is a specialized type of muscle tissue that makes up the walls of the heart. Here are three features of cardiac muscles:

1. Striated appearance: Like skeletal muscle, cardiac muscle has a striated appearance when viewed under a microscope. The striations result from the arrangement of contractile proteins within the muscle fibers.

2. Involuntary control: Unlike skeletal muscle, which is under voluntary control, cardiac muscle is involuntarily controlled by the autonomic nervous system. This allows the heart to beat rhythmically and continuously without conscious effort.

3. Intercalated discs: Cardiac muscle fibers are connected to each other by specialized junctions called intercalated discs. These discs contain gap junctions that allow for rapid electrical communication between adjacent fibers, which is essential for coordinating the rhythmic contraction of the heart.

Explanation: 

Explanation:

A tissue is a group of cells that perform a specific function or work together to achieve a particular task within an organism. In multicellular organisms, cells with similar structures and functions often aggregate to form tissues. Tissues can be found in various organs throughout the body and can be categorized into four main types: epithelial tissue, connective tissue, muscle tissue, and nervous tissue. Each type of tissue has its own unique structure and function that allows it to contribute to the overall health and functioning of the organism.

Explanation:

The xylem tissue is composed of four types of elements, which are:

1. Tracheids: elongated, tube-like cells with tapered ends, which overlap and form a continuous column for water conduction. Tracheids are present in all vascular plants, including ferns, gymnosperms, and angiosperms.

2. Vessel elements: wider and shorter cells than tracheids, with a perforated end wall that allows water to flow freely between adjacent cells. Vessel elements are only found in angiosperms and a few species of gymnosperms.

3. Fibers: long, narrow cells with thick walls that provide structural support to the xylem tissue.

4. Parenchyma cells: relatively unspecialized cells that perform various functions, such as storage, secretion, and wound healing. Parenchyma cells are present in most plant tissues, including the xylem.

Explanation:

The main differences between these two types of tissues are summarized in the following table:

Explanation:

The main differences between these three types of tissues based on their cell wall are summarized in the following table:

Explanation:

Stomata are tiny openings or pores found on the surface of leaves, stems, and other plant organs. They are surrounded by specialized cells called guard cells and play several important functions in plant physiology.

The main functions of stomata are:

1. Gas exchange: Stomata allow the exchange of gases, such as carbon dioxide (CO2) and oxygen (O2), between the plant and the atmosphere. During photosynthesis, CO2 is taken in through the stomata and used to produce sugars, while O2 is released as a byproduct.

2. Transpiration: Stomata also allows for the loss of water vapor from the plant through a process called transpiration. This is important for regulating water balance and preventing dehydration.

Explanation:

There are three types of muscle fibers:

1) Cardiac muscle tissue: This type of muscle tissue is found only in the heart and is responsible for the involuntary contraction of the heart. Cardiac muscle fibers are striated and interconnected in a complex network, allowing for coordinated contraction of the heart.

2) Smooth muscle tissue: This type of muscle tissue is found in the walls of hollow organs such as the stomach, intestines, and blood vessels, and is responsible for involuntary movement of these organs. Smooth muscle fibers are spindle-shaped and lack striations. They are arranged in a crisscross pattern that allows for slow, sustained contractions.

3) Striated muscle tissue: This type of muscle tissue is attached to bones and responsible for voluntary movement of the body. Striated muscles are composed of long, cylindrical muscle fibers that are arranged in bundles and contain multiple nuclei. Striated muscle fibers are striated (have a striped appearance) due to the organization of myofilaments within the fibers.

Explanation:

The specific function of the cardiac muscle is to generate and conduct electrical impulses that coordinate the rhythmic contraction of the heart. The rhythmic contraction of the heart is essential for the pumping of blood throughout the body, delivering oxygen and nutrients to tissues and removing waste products.

The cardiac muscle tissue is specialized and distinct from other muscle tissues in the body. It is striated, like skeletal muscle, but it is also branched and interconnected in a complex network that allows for coordinated contraction of the heart.

Explanation:

Labelled diagram of a Neuron:

Explanation:

a) Epithelial tissue or epithelium is the tissue that forms the inner lining of our mouth.

b) Tendon is the tissue that connects muscle to bone in humans.

c) Phloem tissue is the tissue that transports food in plants.

d) Adipose tissue is the tissue that stores fat in our body.

e) Blood is the connective tissue with a fluid matrix.

f) Nervous tissue is the tissue present in the brain.

Explanation:

Skin: Stratified squamous epithelial tissue.

Bark of tree: Protective tissue and Cork cambium tissue (a type of lateral meristem).

Bone: Osseous tissue (which is a type of connective tissue).

Lining of kidney tubule: Simple cuboidal epithelial tissue.

Vascular bundle: Complex tissue (consisting of xylem and phloem tissues) which is a type of conducting tissues.

Explanation:

Parenchyma tissue is present in various regions of plants, including:

1. Leaves: Mesophyll parenchyma is present in the interior of leaves, responsible for photosynthesis. Parenchyma containing chlorophyll is known as chlorenchyma. 

2. Stems: Pith parenchyma is present in the center of stems, while cortex parenchyma is present in the outer region of the stem.

3. Roots: Cortex parenchyma is present in the outer region of roots.

4. Fruits: Parenchyma tissue is present in fruit pulp, which stores food and provides mechanical support.

5. Seeds: Endosperm parenchyma is present in seeds, which provides nutrition to the developing embryo.

6. Parenchyma in aquatic plants allows them to float as they have air cavities , and are known as aerenchyma.

Explanation: 

Explanation:

Cork is a protective tissue that forms as a secondary tissue in woody plants. It is composed of dead, waterproof cells called cork cells, which are produced by the cork cambium, a type of lateral meristem.

Cork cells are filled with a waxy substance called suberin, which makes them highly impermeable to water and gases. This helps to protect the underlying tissues from excessive water loss and prevents the entry of pathogens.

Explanation:

The completed chart is: