The following topic to be discussed are the basic factors of life, which turn out to be crucial in a living organism. The first topic is metabolism, metabolism in basic terms is how quickly your food breaks down to obtain energy. For example, an older person’s metabolism is much slower than someone who is of a younger age. This is why a younger person can eat a whole pizza and still have gained no weight and have a lot of energy; in an older person this process would take longer, and if they would have the strength to eat a whole pizza, they would be more prone to gaining weight because by the time this four cheese pizza would fully break down, they might have already had 3 sweet tea refills and ice cream.
The next topics are irritability, homeostasis, and growth and development. These subjects are closely related because they all are related to bodily adaptation. Irritability is the ability of organism to respond to the changes in their environment, this is important because it allows the organism to stay balance.
An example of irritability is when the weather begins to get colder, an assortment of animals fur gets much thicker to prepare for the winter to come. Homeostasis is closely related because it is the ability for the body to maintain stability during internal changes despite the occuring external conditions. An example of this is when you shiver during colder weather, your internal body heat refrains from dropping by causing the skeleton muscle to shake and producing warmth.
The last related bodily function is growth and development. This is possibly the easiest function to understand, for you watch it happen from year to year. Growth and development is when your size, weight, height, maturity etc. increases. For example, a toddler goes from being three feet tall and still thinking scribbles are words, to being a seven year old who can read and write basic words.
The last discussed criteria of life is cells and organization. This includes organelle, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystem, and biosphere. These levels of organization start at the smallest unit of life, an atom or organelle, to the largest level or organization which is the biosphere. As each level increases, it include the levels from before. For example, a community includes populations, organisms and every level before that; but it does not include an ecosystem or the biosphere. The organelle contains the mitochondria, chloroplasts, ribosomes etc. Within the cell level, this includes eukaryotic and prokaryotic cells. The tissues include the brain and muscle tissue. Examples of organs are lungs, liver, kidneys etc. Organ systems include the nervous system, skeletal system and many more. Organism would simply be all animals and biotic factors. Populations refer to individuals and of a specific species living in a given place at a given time. A community refers to different species in a given place and time. Ecosystems consist of the living and nonliving factors of the environment. And lastly the biosphere makes up the sky to the rock and water below our feet, and everything in between.