There are a number of ways in which organims can become more complex over generations, but the easiest method to convey and understand is through symbiosis..
On the single-cell level, there are two basic divisions known as "domains". One being called, "prokaryotes", and the other being "Eukaryotes. Eukaryotes are distinctively more complex due to the fact that they contain organelles and a nucleus containing it's DNA, whereas, prokaryotes simply have dna floating throughout their cell. It is thought that eukaryotes developed from multiple prokaryotes living symbiotically until, eventually, some prokaryotes began to live their entire lives inside other ones. This explains why mitochondria inside your own cells have their own DNA separate from the DNA in the nucleus (Apparently, at one time, they were independent organisms which found an advantage in the protection provided by your cells membrane while your cells found an advantage in the abundance of energy that the mitochondria provided).
Multicellular life appears to have developed from multiple eukaryotes grouping together colonially (as in the case of chlorella vulgaris, which became multicellular in a predatory environment under laboratory conditions). As later generations become more reliant on one-another, certain cells become better adapted to specific tasks involved in promoting the overall fitness of the body of cells. This results, eventually, in some cells becoming specialized tissues that, in turn combine to form the specialized structures we call "organs".
The perfect example of all of this is your own body which is literally a walking fortress of creatures that have become symbiotic with all of your specialized tissues which, themselves, have diversified into separate structures over a long series of generations. There are actually more bacteria living in your body performing specialized tasks than there are human cells. If those bacteria weren't there you couldn't digest food or process nutrients. Similarly, those prokariotic bacteria couldn't live without your body.
I'm sure there's someone else who would be glad to explain the genetics, mutations, and the selection mechanisms behind all of the above, but my intent was to keep it as simple as I could.
Simple organisms like bacteria, algae, and some protozoa dominated life during the Precambrian time. These were mostly single-celled and lacked complex structures like tissues or organs.
Soil is a complex mixture of minerals, organic matter, water, and air, so it does not have cell organization. Soil is composed of a variety of materials and organisms, including bacteria, fungi, earthworms, and plant roots, which are not organized in a cell structure like living organisms.
Organic matter is organized into a hierarchy starting with individual molecules, which combine to form macromolecules such as proteins, carbohydrates, and lipids. These macromolecules then assemble into organelles within cells, which in turn organize to form tissues, organs, and organ systems in multicellular organisms. Ultimately, organic matter is structured into ecosystems, where it cycles through various living organisms and the environment.
Complex organisms evolved over time through natural selection, which is the process where organisms with advantageous traits survive and reproduce, passing those traits on to the next generation. This allowed for the development of specialized structures and functions that enabled these organisms to better adapt to their environment and thrive.
World climates are organized into categories based on factors such as temperature and precipitation. These categories include tropical, dry, temperate, continental, and polar climates. Biomes are then organized within these climate categories based on factors like vegetation, wildlife, and adaptations of organisms to specific environmental conditions.
Simple Organism some simple organisms are made of single cell. Others are made of many cells that are similar Complex organisms in complex organisms, cells are organized into tissues, which make up organs. Organs form organ systems.
Fish are considered multicellular organisms. They are complex organisms made up of multiple cells with different functions, organized into tissues and organs.
Usually, complex organisms consist of many organ systems, which comprise from two or more organs, which is from two or more tissues, which comes from two or more cells working for the common function.
Organisms were named organisms because, organisms are highly organized in the way they live. Here is how organisms are organized; Cells Tissues Organs Organ systems Organism Or, Cells= tissues = organs= organ systems = organisim
System
System
In many-celled organisms, cells are organized into tissues, which are groups of cells that work together to perform specific functions. Different tissues come together to form organs, which then work together as organ systems to carry out complex processes necessary for the organism's survival.
Cells are organized into tissues, which are organized into, organs, followed by organ systems and finally organisms.
Cells are organized into tissues, which then form organs. These organs work together in organ systems to carry out specific functions in the organism. Overall, multicellular organisms have a hierarchical organization of cells, tissues, organs, and organ systems to support their complex physiological functions.
The name for a complex organized group of organisms is a "community". This term refers to a collection of different species living and interacting together in a specific environment.
Multicellular organisms can be organized into several hierarchical levels of biological organization. These levels include cells, tissues, organs, and organ systems. Cells group together to form tissues, which combine to create organs, and multiple organs work together within organ systems to support the overall function of the organism. This organization allows for complex functions and interactions essential for survival.
The highest level of organization a sponge has are Cells.