Unit 9 Reflection

In the past two units, we zoomed out of the microscopic view of what we had previously learned. We first focused on ecology. This unit, we learned about Earth's animal population, its evolution, and taxonomy. Along with the traditional vodcasts and notes, we were tasked with a small presentation on a certain animal. This presentation was almost stress-relieving because it was a project, but we had the power to choose what we wanted to put. We did not have any other labs or projects.

https://docs.google.com/presentation/d/1MBv4B7VQrq3Jxy0raEQ_UJpPckNFZYN5mk-YhTZWI3E/edit?usp=sharing

Taxonomy is the naming and classifying of organisms. This study and classification was created to avoid confusion, as the same organisms have many different names and descriptions in different environments of the world. It was created by Carolus Linnaeus, a Swedish botanist in the early 1700s. He created the seven levels of organization with proper classification and the binomial nomenclature system. Phylogeny is the evolutionary history and relationships of species using taxonomy. It is represented using a phylogenetic tree. In the phylogenetic tree are the levels of taxonomy: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
https://upload.wikimedia.org/wikipedia/commons/7/70/Phylogenetic_tree.svg

Then we jumped into the Kingdoms and Domains. There are three domains in taxonomy, and those are the Archaea, Bacteria, and the Eukarya. Inside these three domains there are four kingdoms, the Protista, the Fungi, the Plantae, and the Animalia. The Protista is is very broad and considered the junk drawer, where all the hybrids and mismatches go. The Fungi's defining characteristic is that the kingdom is filled with decomposers. The Plantae kingdom's defining characteristic is that they all photosynthesize. Animalia's defining characteristic is that they are only heterotrophic.

Bacteria and Viruses were the first "animals" we looked at. Bacteria have been that 1% of all species that survive the test of time and have been alive for billions of years. The are about 1/2 a micrometer. They also have cell walls made up of peptidoglycan, which is a network of sugar polymers cross-lined by polypeptides. They move using the flagella, which spirals around forcing movement. Bacteria is important because they are decomposers, nitrogen fixers, and they help in the biotech industry. Viruses are considered nonliving. They latch onto a host cell and take over all machinery. Once a viral genome has entered the cell, the cell begins to manufacture viral proteins. The virus either uses the cell and then kills it, a lytic infection, or it uses it to make copies of the virus, and keeps it alive, a lysogenic.

Fungi used to be considered plants, but they are very different. Once main difference is that plant cell walls are made up of cellulose while fungi cell walls are made up of chitin. Fungi don't photosynthesize either. Fungi are useful for food, medicine, model systems, etc. However they can also be pathogens causing ringworm or athlete's foot, and also Dutch elm. Plants used to be water-dwelling organisms only, but they slowly evolved to land, which gave them a great advantage because they could now reproduce easier and less competition. Cuticles allowed plants to stay hydrated on land, and a vascular system allowed plants to grow off the ground. There are two majors types of angiosperms: monocots and dicots. Monocots have leaf veins that are parallel, have flowers in multiples of 3, and have a bundle of vascular tissue scattered in the stem. Dicots have netlike leaf veins, have flower parts in multiples of 4, and have bundles of vascular tissue in rings of stem.

http://images.wisegeek.com/leaf-diagram.jpg

Invertebrates are diploid and usually reproduces sexually. Most animals have HOX genes, which control early development. They tell the body what to do, when to do it, and how. Instead of talking about every class, I will choose the most significant and explains why. Sponges (Porifera) were the earliest with specialized cells but no tissues. They are immobile and can repoduce sexually and asexually. The Cnidaria phylum has the oldest existing animals, such as jellyfish, sea anemones, coral, hydra, and box jellies. Annelida have segmented bodies, and they have a coelom, which is a fluid-filled space completely surrounded by muscle. The arthropods share many highly adapted features such as chitiin, jointed apendages, and segmented bodies. It is split into 5 groups - the trilobites, the crustaceans, the chelicerates, the insects, and the myriapods. Crustaceans are very diverse and have 2 distinct body sections, a cephalothorax and an abdomen. They also have a pair of appendages per segment. Echinoderms are on the same evolutionary branch as the vertebrates. They have radial symmetry, and use a series of water-filled canals to move around. They also have a complete digestive system. The classes in this reflection are significant because they highlight the evolution of invertebrates in the increasing complexity of the organisms. We first talked about sponges who were filter feeders and weren't even made up of tissues, and then we went all the way to echinoderms, who have a very advanced form of movement along with a complete digestive system. The annelids and mollusks were the middle stages, as we could see the formation of a digestive system.

The Chordata phylum includes all vertebrates. The first is the jawless fish, the Agnatha. These were the first recognizable vertebrates. However, these gave way to the condricthyes and the osteicthyes. These fish had a skeleton made of cartilage or a full bony skeleton, respectively. They also had gills which was huge as it made breathing much more efficient and easier. The last of the aquatic only vertebrates were the lobe-finned fish. These had a pair of pectoral and pelvic fins that were round. They were not as maneuverable, but they could support their own weight, which allowed for adventures onto the shore. The final step to land was the class of Amphibians. They evolved from lobe-finned fish and were tetrapods.  They breathe through their skin, and can lay eggs on both land and in water. Along with the evolution onto land, there came major adaption for reproductive systems. The amniotic egg is a completely waterproof container that holds the embryo and keeps it safe. All amniotes have 2 circuits of blood vessels. The class Reptilia share characteristics such as having a 3 chambered heart, being covered with dry scales, and being an ecotherm. Class Aves are birds that evolved from theropod dinosaurs. They have hollow bones and fused collar bones for flight. These major adaptions allowed for flight. Lastly, the class Mammalia share characteristics such as hair to retain heat, mammary glands, a middle ear, and chewing jaw.

This unit is very tough as we need to not only memorize the taxonomy but also understand the defining characteristics. This is because there is overlap, and you must be able to differentiate. This unit reminded me of the mitosis and meiosis unit because that unit was the hardest for the first semester. We had to memorize, understand, and differentiate for that unit as well.
This was that unit review http://shivpaulgupta.blogspot.com/2016/11/unit-4-reflection.html