1. THE 9 CHARACTERISTICS OF LIVING THINGS
STATION 5
Zombies walk around, they look for food in the form of brains, they seem alive, but when I was in school my teacher told me that they are not living things. How can something that is not living show characteristics of life?
Sponges are the opposite of Zombies, they do not show characteristics of life, but I remember my teacher telling me they are living. How can this be possible? The only sponge that I have seen with any characteristics of life is Sponge Bob, but he is a character from a kids show….ugh, this is all so confusing.
Big Question: Are sponges and Zombies alive? If they are living, like sponge bob why do they not show all the characteristics of DOGS REACH?
Sometimes it is difficult to see all of the characteristics of living things in every organism. Sponges for example do not walk around and actively catch their food in the way that a human does. Similarly a zombie moves around and can sense its surroundings, but does that make the zombie alive? When exploring the question, is something living or non living, there are further observations which can be made to determine whether it is alive or not. These observations are a lot more detailed and may require scientific tools such as microscopes and video capture devices to observe the slightest of movement that could be otherwise missed by the human eye. There are 8 characteristics that can be observed by living thing. (Adaption is a characteristic we cannot observe…..adaptions take hundreds, thousands, or millions of years to occur.)
ALL LIVING THINGS HAVE DNA: Sponges have DNA, the DNA is like a blue print of how to make a new sponge, the DNA is contained in the nucleus of the cells.
ALL LIVING THINGS HAVE LEVELS OF ORGANIZATION: the sponges have cells which are organized to form tissue, the cells have specific functions which relate to the overall function of the sponges.
ALL LIVING THINGS GROW AND DEVELOP: when a new sponge is created through sexual or asexual reproduction it will develop and grow into a mature sponge.
ALL LIVING THINGS CAN SENSE AND RESPOND TO THEIR ENVIRONMENT: the sponge can sense predators, they can then respond by contracting their surface layer which reduces the are that might be exposed to a predator.
ALL LIVING THINGS REPRODUCE: sponges can reproduce asexually, by branching off and producing a new sponge (similar to cutting off your own arm and growing a new you). They can also reproduce sexually. Many sponges are hermaphrodites, meaning they have male and female reproductive organs that work at the same time, they produce sperm, which is the male sex cell and eggs which are the female sex cell.
ALL LIVING THINGS USE ENERGY: sponges move by contracting their muscle cells (movement). These cells need energy in order to contract. Some sponges can make their own food through photosynthesis, others get their food by absorbing nutrients form the water, they do this by allowing water to flow through them, the sugars that was produced by photosynthesis and extracted from the nutrients are reacted with oxygen, which is absorbed from the water, this process of reacting sugar with oxygen is respiration and will produce energy for the sponge. The water also carries out waste products (excretion).
ALL LIVING THINGS HAVE CELLS: sponges have many different specialized cells that run through out its structure. For example it has muscle cells called Myocytes, which contract the sponge (movement).
ALL LIVING THINGS MAINTAIN HOMEOSTASIS: sponges maintain homeostasis by diffusion,
the movement of particles from area of high concentration to areas of low concentration.
(Scan the QR code to watch
a sponge doing diffusion)