When hercyk first arrived we had to start talking about bacteria. We started off by talking about prokaryotes, namely bacteria and archae. We discussed how bacteria have three distinct shapes, Baccili, Cocci, and spirilli. Baccili bacteria are shaped like rods, cocci are spherical, and spirilli are spiral shaped. Bacteria have a variety of ways to get food, including decomposing, photosynthesis, and being a parasite. They are also highly beneficial to us as they help us digest food, make certain foods, and make medicine. There are also harmful bacteria providing some of the most devastating diseases ever inflicted, contaminating food, and being used as a biological weapon.
Archae are different from bacteria, but they used to be classified as bacteria until they were thoroughly examined and compared. The cell wall and membrane are made of different proteins and lipids than that of bacteria. Most archae are chemotrophs, getting energy by breaking down molecules. They also reproduce through binary fission. They also usually live extreme environments and are also identified based in where they live. If they live in a salt rich environment, they are a halophile. If they live in a hot environment then they are a thermophile. If they live in a methogen rich environment then they are a methogen.
We also learned about invertebrates and symmetry. There are three types of symmetry, a-symmetrical, radial, and bilateral. A-symmetry has no symmetry at all. Radial symmetry has a point in the middle that the organism is symettrical around. And when an animal has bilateral symmetry, it has only one line of symmetry and can be perfectly cut in half length wise.
Now we move onto animals. Animals are divided into vertebrates and invertebrates. Vertebrates are animals with a skull and backbone and invertebrates are animals without. The 6 following characteristics are for something to be classified as an animal: they are multicellular, reproduce sexually, develop from embryos, have specialized parts such as organs, they move, and are consumers. Animals are predators and prey, they are hunted and also hunt other organisms. They have come up with way to avoid being eaten though. Some use camouflage to blend in and hide, some have poisonous skin or can spray bad chemicals to deter predators, others have bright colors warning predators that they are poisonous. Some of us wondered how they knew to do this. If they knew from birth it is called innate behavior, but some creatures could modify a behavior making it a learned behavior. Animals also have some seasonal behaviors, such as migrating, or moving to a different place during extreme temperatures. During the winter some animals hibernate. Hibernation is a period of inactivity and decreased body temperature during the winter. Some animals estivate. Estivation is like hibernation during the hotter parts of the summer. They know when to start storing food due to their biological clock, or the internal control of cycles. Some biological clocks control daily cycles. These cycles are circadian rhythms. Some animals know how to migrate by remembering landmarks, or fixed objects. There are birds that even use the earths magnetic field like a compass.
Animals are social and need a way to maintain this, so how do they? They can use communication, or the sending of signals from one animal to another. There are different types of communication such as warnings, identification, intimidation, protecting their homes, courtship, which is used to attract a mate, and protecting their territory. There are other ways to communicate such as pheromones, or communication through chemicals, they can make noises, use body language, or physical touch. Animals also live in groups which can be safer or more dangerous than being alone.
Onto porifera and cnidarians. Sponges (or porifera) have a-symmetry and even though they look like plants, are actually animals. They feed by filtering micro-organisms through their pores, into their collar cells, while the excess water gets pumped through the sponge and through it's osculum to be expelled into the sea. Cnidarians have radial symmetry and can be either polyps or medusas. The main similarity across all cnidarians, is that they have stinging cells. Medusas are bell shaped with tenticles that drape down the bottom, they have a nerve ring instead of a nerve net, the nerve net is common across most cnidarians. Polyps are kinduf an upside-down version of the medusa, but they are more solid and do not have bell shaped bottom. Polyps also stay in one spot most of the time, and have a nerve net.
There are also other types of Invertebrates, like the flatworm, roundworm, tapeworm, annelid worms, arthropods, echinoderms, and mollusks.
Mollusks have bilateral symmetry and are very interesting creatures. They have special parts that other invertebrates do not. The radula for example is one, they use radula like scrapers for algea and other plants that grow on moist surfaces. They also use their radula to lacerate their prey to death and then consume it. Mollusks also only have 1 way to get around, and that is with a singular foot. No legs, just a foot. Some examples of mollusks are, snails, slugs, clams/oysters, and octopuses (and squid).
There are four types of worms, The flatworm is one. It has bitlateral symmetry. The flatworm is a very small invertebrate, about the length of your pinky finger nail. It has eyes and is a predator. It has a incomplete digestive system and only has a mouth. It also does not have many organs and uses a gastrovascular cavity to digest food.
The second type of worm is the roundworm. The roundworm also has bilateral symmetry but differs greatly from flatworms. Roundworms have a complete digestive system and a blood vessel to give blood to its organs. It is also much smalled than all the other worms, almost being micoscopic in size.
The third type of worm is the tapeworm it also has bilateral symmetry, the tapeworm can not travel very well and does not search for prey, instead, it latches onto a host and sucks nutrients from its host bloodstream to provide its own food, it has no eyes and cannot sense anything around it, it is very immobile, but it doesnt really need to be mobile since its whole lif is just hanging inside a host. You do NOT want a tapeworm inside you.
The last "type" of worm goes a little deeper, since they are classified a little differently than the others, they are the annelid worms, annelid means 'segmented' so we will be going over segmented worms like bristle worms, earthworms, and leeches. annelid worms have special segments of their bodies that have certain functions, they also have a closed circulatory system. Bristle worms are aqautic worms that are covered in giant bristles to help them move around underwater, and they mainly try to find prey in the mud in water. Earthworms are everywhere, there is little chance you havent seen one already, they are decomposers and would rather munch on some dirt than a live animal, they also live in the, well, earth... Leeches live in the water mostly and they are parasites just like tapeworms, the difference is, they stay on the outside of a host instead of on the inside, they can also move better and have an anti-coagulant chemical in their saliva to help them drink blood faster.
Echinoderms are another type of invertebrate. They mostly hav radial symmetry and they are also have a special way of staying alive, they use a water vascular system. A water vascular system takes in water and pumps it though the water to help the echinoderm move using little tubes on the end of their feet .Some examples of echinoderms are starfish, sea urchins, and sea cucumbers.
The last type of invertebrate are arthropods, arthropods means "jointed legs" in greek. One main thing that all arthropods have in common is their exoskeleton and jointed legs. Arthropods are split into a few groups, those groups being: 1. arachnids, arachnids are your spiders and eight legged arthropods, they also don't have 3 segments, they only have two, the cephalothorax and the abdomen. 2.insects, insects make up most of the world and are absolutely everywhere, they have 3 segments and 6 legs, and alot of them have compound eyes. 3. crustaceans, crustaceans are very similar to insects and have 3 segments and 6 legs, but alot of them live underwater and are amoung some of the most successful species in the world, as they are found as much in water as insects are found on land. Some examples are, lobsters, hermit crabs, and shrimp. There are also centipedes and millipedes that have many segments and many legs and are very long. Centipedes are carnivores and Millipedes are herbivores, centipedes have poison as millipedes do not.
Moving on to vertebrates. We learned about three kinds. These are fishes, reptiles, and amphibians. Fishes are aquatic vertebrates, one of the most abundant forms of life in a body of water. Fishes are also ectothermic. The following are the three types of fish: jawless, bony, and cartilaginous. Jawless fish include lampreys and hagfish and were some of the earliest fishes, being smooth and slimy, they also had lungs. They next ones were cartilaginous fish with jaws as an adaptation. They also had a system of fins, a skeleton made of cartilage, and a lateral line system, they also have gills. Cartilaginous fishes are contained of sharks, Rays, and skates. They also have denticles, teeth like structures on their skin. They final type of fishes are bony fishes. These fish are divided into two categories, Ray-finned and lobe-finned. These fishes are common fish, with fins and a swim bladder to stay afloat. They have a skeleton made of bone, giving them the name of bony fish.
Now reptiles. Reptiles were one of the first vertebrates fully adapted to life on land. Unlike amphibians, reptiles have thick dry to preserve water. They also have an amniotic egg, or an egg with a protective shell, which also preserves water. Reptiles also reproduce using a system known as internal fertilization. Reptiles are ectothermic as well. Reptiles are generally divided into the four following groups: turtles and tortoises, alligators and crocodiles, lizards, and snakes. Turtles and tortoises are inflexible but have a highly protective shell. Tortoises have legs while turtles have a fin-like structure to hell swim underwater. They also usually lay their eggs in mud or sand on land and bury them. When they hatch they will squirm their way up. Alligators and crocodiles are some of the biggest reptiles and are carnivores, eating only meat. They have a tail to help speedily swim and navigate through water and are comoflauged to blend in to the water, exposing only their head. The largest groups of reptiles are lizards making up 4000 species. Lizards also live in diverse climate from jungles to deserts. Most species of lizards are omnivores, eating plants and meat. The next species are snakes, the only reptiles to lack legs. Snakes are able to move due to contractions of their body. Snakes are also carnivores, eating eggs and small animals. The way they eat their prey is also different, they swallow them whole. Snakes don't have very good senses but they can smell well to track their prey. They smell by flicking their tongue out and pulling molecules from the air inside of its mouth and senses them there.
Amphibians were some of the first vertebrates to go onto land, and some of the first to have lungs to hold air. The first amphibians were likely to have looked like a cross between a salamander and fish. Amphibians have two stages to their life, one in the water and one on land post-metamorphosis. Amphibians have smooth, moist, thin skin where they absorb water. Some can breathe by gulping air into their lungs and other breath by absorbing oxygen through their skin. Pre-metamorphosis amphibians are called tadpoles, or an aquatic larvae that developed in the water as well as developing feet and lungs. There are three types of amphibians as listed here: Caecilians, which are snakelike with bony scales, salamanders, the closest amphibian to its ancestors with some not even going through metamorphosis, and frogs and toads, the most common type of amphibian found in diverse climates with powerful leg muscles and developed vocal cords for calling and singing.
Thank you for taking the time to see our presentation. Have a nice day!
Credits:
Created with images by Paul from www.Castaways.com.au - "Great Barrier Reef, Eddy Reef off Mission Beach"