1. a group of cells with a common structure and function.
2. usually composed of several types of tissues that together perform a specific task.
3. groups of several organs that work together to perform the functions of the body.
4. compact, complex animals have specialized that provide a large surface area.
5. the protective covering of the body is called the
6. the regulation of internal conditions within a range that supports life's processes.
7. most of the control mechanisms that maintain an internal steady state are based , in which a change in a variable triggers mechanisms that reverse that change.

1. Tissues are a group of cells with a common structure and function.

2. Organs are usually composed of several types of tissues that together perform a specific task.

3. Organ systems are groups of several organs that work together to perform the functions of the body.

4. Compact, complex animals have specialized internal exchange surfaces that provide a large surface area.

5. The protective covering of the body is called the integumentary system.

6. Homeostasis is the regulation of internal conditions within a range that supports life's processes.

7. Most of the control mechanisms that maintain an internal steady state are based on negative feedback, in which a change in a variable triggers mechanisms that reverse that change.

Explanation:

1. Tissues are a group of cells with a common structure and function.

It is called tissue, a structure constituted by an organized set of cells of the same nature, which perform a common function. For example, muscle tissue is formed by cells called myocytes or muscle fibers that have the ability to contract. Its function is to generate the movements of organs and organisms.

2. Organs are usually composed of several types of tissues that together perform a specific task.

An organ is a collection of tissues that structurally form a specialized functional unit to perform a specific function. For example, the heart is an organ that is responsible for pumping blood to the rest of the body and to the lungs.

3. Organ systems are groups of several organs that work together to perform the functions of the body.

A set of organs that fulfill similar functions or have the same final purpose form an organ system.

4. Compact, complex animals have specialized internal exchange surfaces that provide a large surface area.

The exchange surface is understood as the place where the exchange between internal and external substances in the environment occurs. In animals, for example in the group of vertebrates with the exception of fish, they are characterized because they have pulmonary respiration. The lungs are bags of thin walls that serve to perform the gas exchange, for which they connect with the outside through a series of ducts.

5. The protective covering of the body is called the integumentary system.

The integumentary system is formed by the skin and its annexes. It is essential for the body, as it represents the first barrier of protection against external invading agents.

6. Homeostasis is the regulation of internal conditions within a range that supports life's processes.

Homeostasis is the state of dynamic equilibrium or the set of self-regulation phenomena that allow the maintenance of a relative constancy in the composition and properties of the internal environment of an organism.

7. Most of the control mechanisms that maintain an internal steady state are based on negative feedback, in which a change in a variable triggers mechanisms that reverse that change.

The negative feedback seeks to maintain the balance or original state of the system, responding with the objective of reducing the effects of the actions that caused some change.

"d.) carbon dioxide and hydrogen sulfide"