Question

The level of organization that includes two or more tissues that work together is a(n). a. organ. b. tissue. c. organ systern. d. organism.

Short answer

The level of organization that includes two or more tissues working together is an \(organ\). The correct answer is choice \(a. organ\).

Step-by-step solution

Understand the Hierarchical Structure

In the biological organization of multicellular organisms, tissues working collectively to perform a specific function form a structure higher than a tissue. When we examine the structure hierarchy, it is clear that a group of tissues working together takes place in an organ.

Matching the Definition with the Terms

The level of organization which comprises two or more tissues that work collectively is defined as an organ. Therefore, based on the given choices, the correct answer is: a. organ. The other terms are either a lower level (b. tissue), a higher level (c. organ system), or the highest level (d. organism) in the hierarchical structure of biological organization. So these choices don't match the definition given in the question.

Key concepts

Organ

Organs are fascinating components of living organisms. They are formed when several tissues work together to perform a specific function necessary for the survival and normal functioning of the body.
Each organ is distinct because it is composed of different types of tissues, each contributing to the overall function of the organ. For example, the heart is an organ consisting of muscle tissue that helps it contract and connective tissue that supports its structure.
Organs are crucial for maintaining homeostasis within the body, ensuring that internal conditions remain stable in response to changes in external factors.

• Organs perform specialized tasks.
• They help maintain balance in biological systems.
• They are made up of multiple tissue types.

By understanding organs, you can see how different tissues collaborate seamlessly to create a well-functioning system.

Tissues

Tissues are groups of similar cells that work together to carry out a specific function. They are one of the foundational levels of biological organization, existing below organs.
In the human body and other organisms, there are four primary types of tissues: epithelial, connective, muscle, and nervous tissue.

• Epithelial tissues: Cover body surfaces and line body cavities, offering protection and selective permeability.
• Connective tissues: Provide support and structure, holding various body parts together.
• Muscle tissues: Enable movement by contracting and relaxing.
• Nervous tissues: Transmit signals to coordinate bodily functions.

Understanding tissues gives insight into how cells with similar structures can have specialized roles, highlighting the complexity and organization within a living body.

Organ System

An organ system is a higher level of organization compared to organs. It consists of multiple organs that work together to perform complex functions vital for the survival of the organism.
For example, the digestive system includes organs like the stomach, intestines, and liver, all working in unison to process food and absorb nutrients.
Organ systems efficiently coordinate their activities, often relying on one another to maintain the body’s well-being and help in adapting to internal and external changes.

• Organ systems are comprised of several organs.
• They enable complex processes and interactions within the organism.
• Examples include the circulatory, respiratory, and nervous systems.

Recognizing how organ systems operate can lead to a deeper understanding of the integration and interdependence required for life.

Organism

An organism represents the most complex level of biological organization, encompassing organ systems, organs, tissues, and cells. An organism can be as simple as a single-cell bacterium or as complex as a human being.
It is the complete living entity capable of reproduction, growth, response to stimuli, and adaptation to the environment. Organisms are highly organized, ensuring survival through a combination of intricate interactions between their systems and the surrounding environment.

• Organisms can be unicellular or multicellular.
• They perform all necessary functions to sustain life.
• In multicellular organisms, there is a high level of organization and coordination.

Appreciating the organism level helps in understanding the culmination of biological processes and systems to form life as we know it.