Answer;
Cell
Explanation;
-The biological levels of organization of living things arranged from the simplest to most complex are: organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere.
-Cell is the basic unit and building block of life. It is bound by a cell membrane, and possesses a nucleus which acts as its brain. Arachnoidiscus ehrenbergi is an example of diatoms which are unicellular, therefore it is a cell.
Endocrine gland - a group of cells that secretes substances into the blood or directly into an organ.
Differ from exocrine glands, endocrine glands have no ducts and secrete products (hormones) directly into blood.
Hormone - a substance produced by cells that helps specific groups of cells to perform specific functions. It is a product of endocrine gland which functions as chemical messengers to stimulate other cells.
Duct – a channel or tube that conveys a substance. It is part of the exocrine glands (such as salivary glands) which makes contact with surface .
Answer:
A planet is a celestial body that revolves around a star. In our solar system, Earth is the third planet from the sun. The word planet comes from the Greek planetes, which means "wanderer." Since ancient times, people have been fascinated by the wandering of celestial bodies in the night sky.
Explanation:
3) decrease
Without the green house effect, earth would be like a solid ball of ice and rock.
Life as we know it wouldn't exist without greenhouse gases.
The temperature would drop below 0° Fahrenheit!
