classification of living things - brian 2

All terrestrial life forms are divided into kingdoms and are farther broken down into phylum, classes, order, family, genus, and species. Before kingdoms though, there are domains. There are three domains: Archaea, Eubacteria, and Eukaryota. There are four kingdoms: Protista, fungi, plantae, and animalia. These are just the first couple steps in classifying living things. This system has been around for a while and has been altered and revised many times due to new discoveries and advancements. Within each kingdom, species are farther classified into groups based on similarities. For example, the full classification of a human is:
Domain- Eukarya
Kingdom- Animalia
Phylum-chordata
(subphylum- vertabrata)
class- mammalia
order- primates
family- hominidae
genus- homo
species- sapiens.

Classification of living things - Brian

All terrestrial life forms are divided into kingdoms and are farther broken down into phyla, classes, order, family, genus, and species. There are four kingdoms: Protista, fungi, Plantae, and animalia. This is just the first step to fully breaking down the classification of living things.

Classifications of Life

Today we will be explaining the seven classifications of life which help scientists put animals, plants, and other organisms into categories. Putting animals, plants, and organisms into categories is important because it helps scientists avoid confusion. This system was created by the Swedish botanist Carl Linnaeaus in 1757, which we today refer to as binomial nomenclature. The seven classifications of life in descending order are: Kingdom, phylum, class, order, family, genus, species. In 1990, three domains were created seperating single-celled organisms(archaea), unicellular microorganisms(bacteria), and complex celled organisms(eukarya), which includes protista, animalia, plantae, and fungi.

Questions for the Responder:
1.) What is the kingdom, phylum, class, and order of the reticulated python?
2.) Why is the classificaton of eukaryotes a controversial issue?
3.) Explain cladistics and why they are important to the subjects we are studying?

Taxonomy- The Science of Classifying Organisms

There are many different organisms, and scientists needed a way to classify them. Carlos Linnaeus, an 18th century scientist, came up with a system called binomial nomenclature, which means a "two name system." The two names were Genus and Species. Other scientists would later update the system to include more categories such as Kingdom, Phylum, Class, Order and
Family.
Taxonomy is the science of classifying organisms. The largest category is called the Kingdom, and this is broken down into a smaller group called a Phylum. Class is smaller than a Phylum, and so on. There are five major kingdoms used to classify living organisms:

1. Animalia: made up of animals, i.e. ants, frogs, horses, humans
   
2. Plantae: made up of plants which are organisms that can use photosynthesis to make their own food, i.e. trees, grass, cacti, algae
   
3. Fungi: feed on dead organisms, help the decaying or decomposing process of these organisms, i.e. mushrooms, mold
   
4. Protista: one-celled organisms that have a nucleus, i.e. Amoeba, Protists, Euglena
   
5. Monera: one-celled organisms that do not have a nucleus, i.e. Eubacteria, Archaebacteria

Before scientists can classify an organism, they have to make sure that it is living. The guidelines for living things are:

• They reproduce
• They use and make energy
• They respond to the environment
• They adapt to their environment
• They grow

The Kingdom Animalia is made up of organisms from ants to bears and even includes humans.

The Kindgom Plantae consists of plants that are multicellular and able to make energy from the sun.

The Kindom Fungi consists of multicelluar organisms that do not make their own food. Most are decomposers that break down dead organisms. The most common fungus is a mushroom.

The Kingdom Protista consists of unicellular or single celled organisms, with a nucleus. Some can make their own food, but others do not. These organisms are so small that we have to use a microscope to see them.

The Kingdom Monera consists of organisms that are unicellular and do not have a nucleus. These organsims are called bacteria.

1. There are some nonliving things that can act like a living organism. These are not classified in the kingdoms of living organisms. An example of one of these organisms is virus. Even though it can reproduce inside a cell, why isn't virus considered a living organism?
2. What are the two major groups of bacteria?
3. How are the Genus and species names written according to binomial nomenclature?

Carbon Dating

Carbon dating is a type of radioactive dating used to identify the age of human, animal, and plant remains. This method uses an isotope of carbon, carbon 14, which is formed when cosmic rays enter our atmosphere, strike nitrogen, and change it into another element. This isotope is radioactive and has a half-life of 5,730 years. This means that the quantity of carbon 14 in an organism will be cut in half every 5,730 years. All organic matter has both carbon 12(the most abundant form of carbon) and carbon 14, which is much less in abundance. Since C12 does not decay scientists compare the ratio of C12 in a sample to the amount of C14 left and they then can estimate how much C14 was there to begin with. Today, the ratio in the atmosphere is about one C14 atom for every one trillion C12 atoms. Here is an example, if a fossil is discovered and there is one C14 atom for every two trillion C12 atoms, you can assume that the fossil is 5,730 years old since the radioactive carbon has decayed one half-life. Basically, scientists date organic material based on the amount of C14 left in a sample compared to the amount of C12.

There are several flaws with this method of dating. One is that the method only works for organic material that is 60,000 years old or younger because by the time something reaches that age, the amount of C14 left becomes untraceable. Scientists can only account for around 10 half-lives of C14. Also, we are assuming that the ratio of C12 atoms to C14 was the same in the past as it is today. Since radioactive carbon is forming 28-37 percent faster than it decays, our environment has not yet reached equilibrium and the amount of C14 in our environment is constantly increasing. We have no way of undoubtedly knowing how much C14 was originally in a sample.


Questions:
1. What is the instrument used to detect C14 and briefly explain how it works.

2. Into what element does Carbon 14 decay?

3. What is another way to find the age of organic material?

Paleontology

Paleontology is the study of ancient life. It includes organisms' evolution and interactions with each other and their environments. Since it is a “historical science,” researchers explain causes instead of conducting experiments. This science has been around since the 18th century.
Paleontologists study mainly fossils to learn the history of the earth and evolution of mammals. They can sometimes work together with archeologists, who primarily study objects made by humans and human remains, since they study the evolution of humans as organisms.
Due to an increase in knowledge, paleontology has been broken down into several subdivisions, all studying the fossils of different organisms. There are also different kinds of fossils that paleontologists study, like trace fossils and body fossils.

Questions (:
What is stratigraphy and how does it relate to paleontology?

Name and briefly describe two subdivisions of paleontology.

What is mass extinction, when was the last mass extinction, and what became extinct after it?

Paleontology

Paleontology is the study of prehistoric life, including organisms' evolutions and interactions with each other and with their environments. Paleontologists have made observations dating back to the 5th century BC. They study ancient plants, rocks, fish, dinosaurs, mammals, insects, and much more. They search for fossils in rocks from all over the earth, discovering clues that will help them recreate what life was like in the ancient past. Paleontology is a "historical science", which means that instead of conducting experiments to observe effects it aims to explain causes. Paleontologists study fossils to derive what conditions were like during the lifetime of the fossil. Paleontologists can look at a fossil found somewhere and determine the age of the environment surrounding the fossil such as ice or rock. Through a paleontologists studies they can confer reasons as to extinctions, ice ages, and global warmings.

Questions :



1) What is the difference between paleontology, arthropology, and archeology?

2) How do paleontologists date their fossils in order to define the time period from which they came?

3) How can paleontologists use their findings to pridict the Earth's organic and inorganic past?

Evolution is, simply stated, the gradual change and development of a species due to the environmental challenges it experiences. In this way, species have developed over the millenia in order to become well-adapted in their habitat. The Darwinian concept of "survival of the fittest" is a large part of the evolutionary sequence. Species which are not well-adapted to their environment usually die out and are replaced by a species with a better chance of survival.

Creationism (or creation science as it is sometimes called) is a direct contradiction to evolution. Creationism explains the development of species as being the product of an intelligent mind, more commonly refered to as God. The theory is based upon a literal interpretation of the Bible, with all modern-day species being develped at the same time as man, and without the process of natural selection taking place

1. What are some important court cases involving evolution and natural selection?

2. How was the theory of evolution and the theory of creationism developed?

3. How has each theory been "proven?"