Plant Tissues Overview

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Questions and Answers

Which tissue type is responsible for primary growth in plants?

Intercalary meristem

Apical meristem (correct)

Permanent tissue

Lateral meristem

Which characteristic is NOT associated with meristematic tissue?

Absence of intercellular spaces

Thin cell walls

Presence of large vacuoles (correct)

Ability to divide

What characteristic is true of permanent tissues?

They are composed of cells that cannot divide. (correct)

They can divide indefinitely.

They have no definite shape or size.

They consist only of dead cells.

What type of permanent tissue is responsible for supporting plants and storing food?

Parenchyma Signup and view all the answers

What type of permanent tissue is involved in support and strength?

Collenchyma Signup and view all the answers

Which characteristic is associated with collenchyma cells?

They provide flexibility and support. Signup and view all the answers

Which meristem leads to the thickening of stems and roots?

Lateral meristem Signup and view all the answers

What is unique about chlorenchyma within parenchyma tissues?

It contains chlorophyll for photosynthesis. Signup and view all the answers

Which of the following is a type of complex permanent tissue?

Phloem Signup and view all the answers

What best describes the cells of parenchyma tissue?

Alive with thin walls and large gaps. Signup and view all the answers

What is the primary function of xylem sclerenchyma?

Mechanical support Signup and view all the answers

What types of cells make up phloem?

Sieve tubes, Companion cells, Phloem fibers, and Phloem parenchyma Signup and view all the answers

How can the age of a tree be determined?

By counting the number of annual rings Signup and view all the answers

What happens to the nucleus of a sieve cell at maturity?

It degenerates but the cytoplasm persists Signup and view all the answers

Which statement about xylem elements is correct?

Only xylem parenchyma is a living element Signup and view all the answers

What is the main function of tracheids in the xylem?

Conduction of water and minerals Signup and view all the answers

Which xylem component is characterized as advanced and primarily found in angiosperms?

Vessels Signup and view all the answers

What type of cells in xylem are primarily responsible for starch storage?

Xylem parenchyma Signup and view all the answers

Which characteristic best describes xylem vessels?

They form a continuous channel for efficient conduction Signup and view all the answers

What is a key distinction of xylem sclerenchyma compared to other xylem components?

It provides mechanical support Signup and view all the answers

What function does the epidermis serve in desert plants?

Reducing water loss Signup and view all the answers

What is the main function of cork in trees?

Protection from infections Signup and view all the answers

Which type of tissue in animals is responsible for covering body surfaces?

Epithelial Tissue Signup and view all the answers

What is the primary function of collenchyma tissues in plants?

Allow flexibility for bending without breaking Signup and view all the answers

How do epidermal cells in plant roots enhance water absorption?

By increasing surface area Signup and view all the answers

Which characteristic accurately describes sclerenchyma cells?

They have thick walls and are dead Signup and view all the answers

What happens to the tissues of bark as they age?

They are replaced by secondary meristem Signup and view all the answers

Where are collenchyma tissues predominantly located?

In leaf stalks just below the surface Signup and view all the answers

What is a significant feature of sclerenchyma tissue?

They provide structure through lignin thickening Signup and view all the answers

Which of the following is NOT a characteristic of collenchyma cells?

They are dead and narrow Signup and view all the answers

What is a primary function of epithelial tissue?

Protect underlying structures Signup and view all the answers

Which type of epithelial tissue would be found lining the inner surface of the intestines?

Columnar Epithelium Signup and view all the answers

Which type of muscular tissue is characterized by visible striations?

Cardiac Muscle Signup and view all the answers

Which characteristic is NOT associated with epithelial tissue?

Highly vascularized Signup and view all the answers

What distinguishes cardiac muscle from other types of muscular tissue?

It is found in the heart and shows striations Signup and view all the answers

What is the primary function of phloem tissues?

Conducts organic solutes or food materials. Signup and view all the answers

Which of the following best describes the direction of conduction in phloem?

Bidirectional between leaves and storage parts. Signup and view all the answers

Which plant tissue is responsible for mechanical support in relation to phloem?

Phloem fibers. Signup and view all the answers

What type of cells are associated with the transport of substances in phloem?

Sieve tubes. Signup and view all the answers

Which of the following tissues serves as the outer protective layer of plants?

Epidermis. Signup and view all the answers

What is a key feature of skeletal muscles?

They are voluntary and multinucleated. Signup and view all the answers

Which statement accurately describes cardiac muscle fibers?

They are branched and uninucleated. Signup and view all the answers

What type of muscles are non-striated muscles commonly referred to as?

Smooth muscles Signup and view all the answers

Where in the body would you primarily find smooth muscles?

Walls of hollow organs and blood vessels Signup and view all the answers

Which of the following best describes the structure of smooth muscle fibers?

They are spindle-shaped and uninucleated. Signup and view all the answers

Which type of muscle is under voluntary control?

Striated Muscle Signup and view all the answers

What feature distinguishes cardiac muscle from striated and non-striated muscles?

It has intercalated discs Signup and view all the answers

Which component constitutes the largest percentage of blood?

Plasma Signup and view all the answers

What is the main function of non-striated muscle?

To control involuntary movements like peristalsis Signup and view all the answers

Which of the following features is NOT characteristic of connective tissue?

Has a striated appearance Signup and view all the answers

Study Notes

Plant Tissues

Plant tissues are categorized into two main types: Meristematic and Permanent.
Meristematic tissue consists of cells that have the ability to divide.
- These cells are small, isodiametric, and have thin cell walls.
- Apical meristem: Found at the tips of stems and roots, responsible for primary growth (plant becoming taller).
- Intercalary meristem: Located at the base of leaves or between nodes on branches, helping in the growth of internodes and leaves.
- Lateral meristem: Responsible for secondary growth (plant becoming thicker).
Permanent tissue consists of cells that have lost the ability to divide.
- These cells are large, have varied shapes, and thick or thin cell walls.
- Simple permanent tissue includes parenchyma, collenchyma, and sclerenchyma.
- Complex permanent tissue includes xylem and phloem.

Parenchyma

Forms the basic packing tissue in plants.
Cells are simple, not highly specialized, and alive.
Cells have thin walls and large gaps between them.
Chlorenchyma: Parenchyma containing chlorophyll that performs photosynthesis.
Aerenchyma: Parenchyma with large air spaces, aiding plants in floating.

Collenchyma

Found in leaf stalks just below the surface.
Provides flexibility, allowing leaves and stems to bend without breaking.
Cells are alive, long, have thick corners, and have very little space between them.

Sclerenchyma

Found in stems, around vascular bundles, in leaf veins, and in the hard coverings of seeds and nuts.
Provides hardness and stiffness.
Cells are dead, long, and narrow with thick walls strengthened by lignin.
The hard husk of a coconut is made of sclerenchyma tissue.

Xylem

Also known as wood, it's a vascular and mechanical tissue.
Thick-walled cells form tubular passages for water and mineral conduction.
Consists of four types of cells:
- Tracheids: Elongated, angular dead cells mainly involved in water conduction in gymnosperms.
- Vessels: Cylindrical tube-like structures forming a continuous channel for efficient water conduction (generally found in angiosperms).
- Xylem parenchyma: Small, thick-walled cells used for starch storage.
- Xylem sclerenchyma (Xylem Fibre): Non-living fibers with thick walls and narrow cavities that provide structural support.

Phloem

Consists of both parenchymatous and sclerenchymatous cells.
Contains four types of elements: Sieve tubes, companion cells, phloem fibers, and phloem parenchyma.
Sieve tubes: Slender, tube-like structures made up of elongated, thin-walled cells placed end-to-end.
- The end walls are perforated by pores called sieve plates.
- The nucleus degenerates at maturity, but cytoplasm persists due to protoplasmic continuation with companion cells via plasmodesmata.
- Sieve cells contain slime protein involved in growth and repair.
Companion cells: Have dense cytoplasm and prominent nuclei.
- They are sister cells to sieve cells, originating from a single mother cell.
Phloem fibers: Provide mechanical support to sieve tubes.
Phloem parenchyma: Store food and help in radial food conduction.

Comparison of Xylem and Phloem

Feature	Xylem	Phloem
Function	Conducts water and minerals	Conducts organic solutes or food materials
Direction of Conduction	Mostly unidirectional (from roots to apical parts)	Bidirectional (from leaves to storage/growing parts or vice versa)
Conducting Channels	Tracheids and vessels (dead elements)	Sieve tubes (living elements)
Living Elements	Xylem parenchyma (only living element)	Sieve tubes, companion cells, and phloem parenchyma
Dead Elements	Tracheids, vessels, and fibers	Phloem fibers
Mechanical Support	Provides mechanical strength to the plant	Does not perform a mechanical function

Protective Tissues

Epidermis: The outer protective layer of the plant.
- In desert plants (xerophytes), a thick cuticle reduces water loss by lowering transpiration rate.
- In roots, epidermal cells increase surface area for better water and nutrient absorption.
Cork tissue: Another protective layer, found in older parts of the plant.
- It protects the tree from bacterial/fungal infection and prevents water loss.

Animal Tissues

Animal tissues are classified into four main types: Epithelial, Muscular, Connective, and Nervous.
Epithelial tissue covers organs and lines cavities of hollow organs.
- Cells are closely packed on a non-cellular basement membrane.
- No blood vessels or nerves.
- Primary function is protection.
- Squamous epithelium: Found in the inner surface of the mouth, esophagus, blood vessels, and alveoli (lungs).
- Cuboidal epithelium: Found in the nephron (kidney tubules) and salivary glands.
- Stratified squamous epithelium: Found in the outer layer of skin.
- Columnar epithelium: Found in the inner surface of the intestine and alimentary canal.
- Ciliated epithelium: Found in the trachea, bronchi, fallopian tubes, nasal cavity, bronchioles, and uterus.
Muscular tissue aids in movement in the body.
- Cells are long and fiber-like, capable of contraction and relaxation.
- Striated muscle (skeletal muscle): Show striations, are voluntary muscles controlled by will.
- Cardiac muscle: Show striations, are involuntary muscles found in the heart walls, and have a rhythmic contraction and relaxation pattern.
- Smooth muscle: No striations, are involuntary muscles found in the walls of stomach, intestines, urinary bladder, bronchi, iris of the eye, etc., and are responsible for peristaltic movements in the alimentary canal.
Connective tissue provides structural framework, connects body parts, offers protection against infections, stores fats, and fills spaces.
Blood is fluid connective tissue that transports gases, digested food, hormones, and waste materials throughout the body.
- Consists of plasma (55% of blood) and blood cells.
- Plasma: About 90-91% water, 7 % protein, and 0.9% inorganic salt.
Nervous tissue is responsible for communication and coordination in the body.

Comparison of Muscle Types

Feature	Striated Muscle (Voluntary)	Non-Striated Muscle (Smooth)	Cardiac Muscle
Control	Voluntary (under the control of one's will)	Involuntary	Involuntary
Location	Attached to the skeleton	Walls of stomach, intestine, urinary bladder, bronchi, iris, etc.	Walls of the heart
Structure	Multinucleated and unbranched fibers	Uninucleated, spindle-shaped fibers	Uninucleated and branched fibers
Membrane	Enclosed by a thin membrane called sarcolemma	Not enclosed by a membrane, fibers joined in bundles	Enclosed by sarcolemma with intercalated discs
Cytoplasm	Called sarcoplasm	Called sarcoplasm	Called sarcoplasm
Fatigue	Get tired and need rest	Do not get tired easily	Do not get tired, rhythmic contraction and relaxation occur
Appearance	Striated (striped appearance)	Non-striated (smooth appearance)	Intermediate structure between striated and non-striated
Function	Responsible for voluntary movements	Controls involuntary movements like peristalsis	Controls rhythmic contraction and relaxation of the heart

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Description

Explore the fascinating world of plant tissues, including their types and functions. This quiz covers meristematic and permanent tissues along with their subtypes, such as parenchyma and xylem. Test your knowledge and understanding of plant biology!