Characteristics of Living Things
Answer Activity No. 2.1 CHARACTERISTICS OF LIFE
The study of life Living things are known as organisms. The living world and the non-living world are mixed. As you look out the window here at school or as you investigate any environment you will find a mixture of the two. How can we identify something as an organism? For each of the items listed below state a reason that makes it living or non-living: Clouds Mushrooms Worm Fire Automobile
What characteristics do all living things share?
1. Living things are made up of units called cells (Organized) Some organisms are made of only one cell and some are made of trillions of cells. Cells are small self-contained units of living material that are separated from the surroundings by a barrier.
Unicellular organism made of only one cell
Multicellular organism made of more than one cell. In complex multicellular organisms such as humans, many different types of cells work together to perform the functions needed by the organism. Spirogyra is a common freshwater alga hydra (animal)
2.Living things reproduce: Reproduction is the life process that provides for continuation of the species. An individual will not die if it does not reproduce but the species will end if no members reproduce.
Sexual reproduction -requires cells from 2 parents to create a new individual different from each parent. Common in multi-cellular organisms (trees, birds etc.) Asexual reproduction -requires only one parent. Offspring is identical to parent.
3.The traits of living things are determined by the genetic code: (Composed of DNA) When organisms reproduce they pass on genetic information in the form of DNA to the offspring. In sexually reproducing organisms the offspring obtain a mixture of genetic information from each parent. In asexually reproducing organism the offspring have identical genetic information to the parent
4.Living things grow and develop. (GROWTH and DEVELOPMENT) Every organism has its own life-cycle a pattern of growth and change that occurs over the organisms lifetime.
5.Living things obtain and use materials and energy. (Metabolism) Examples Oxygen and sugar are needed by organisms to make energy. Food is needed to help build the body
Chemical reactions take place in the body to convert the materials from the environment into forms usable by the organism. Metabolism is the collection of all the reaction that take place within an organism. Examples of Metabolic Reactions: Building Cells Breaking down cells Converting oxygen and glucose to energy and carbon dioxide.
6. Living things respond to their environment. (SENSITIVITY) Organisms live in a constantly changing environment. Examples: Light, temperature and amount of water change from day to day and season to season. Plants and animals must respond to these changes or they will die.
7. Living things maintain and a stable internal environment. (HOMEOSTASIS) The steady state (balance) inside an organisms body is known as HOMEOSTASIS. While the environment outside changes an organism must be able to keep conditions inside mostly the constant. If homeostasis is disturbed the organism will become sick and will die if the balance is not fixed.
8. Taken as a group, living things change over time (Evolutionary Adaptation) Life has changed significantly over the history of the earth. The process of this change is known as evolution.
CHECK YOUR UNDERSTANDING #1: In essay format discuss what characteristics all living things have in common and how life on earth is different. Be sure to include the following terms in your response in a way that demonstrates an understanding of the term: Organism, unicellular, multi-cellular, sexual reproduction, asexual reproduction, life cycle, metabolism, homeostasis, evolution
Sample Essay Living things (organisms) can be distinguished from non living things by several characteristics and abilities. All organisms are comprised of cells. Whether organisms are made up of a single cell (unicellular) or many cells (multicellular) they are able to carry out similar processes. To continue the species all organisms must be able to reproduce. Some species reproduce by combining genes from two parents in a process known as sexual reproduction. Some species reproduce asexually and produce a genetically identical offspring. All organisms carry on chemical reactions in their body, called metabolism, that allow them to maintain a state of homeostasis or internal balance. Over time, life on earth has evolved to include these common characteristics, but life has developed many different ways of accomplishing these processes.
The Scale of Biology Sub-Units of metric system used in Biology Tools for length Kilo 1000 times Centi 1/100 th Milli 1/1000 th Micro 1/1,000,000 th Nano 1/1,000,000,000 Measuring Tape Ruler Ruler Light Microscope Electron Microscope
For each of the following organisms listed below choose the appropriate scale of measurement (metric) for scientists to use: Kilograms Weight of an Elephant Width of a Bacteria Micrometers Celsius or Kelvin Temperature of a liquid Length of a feather Centimeters Weight of a feather Grams Height of a person Meters
Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html
Definition of Cell A cell is the smallest unit that is capable of performing life functions.
First, what is a cell?! It took a long time for people to discover cells and figure out what they were all about. They need sophisticated equipment (microscopes) to be able to see cells. Every thing we know about cells we call cell theory.
Examples of Cells Amoeba Proteus Plant Stem Bacteria Red Blood Cell Nerve Cell
Cell Theory says that. 1. All living things are made of cells. 2. Cells are the basic units of structure and function in all living things. In other words, cells are like the building blocks of all living things. 3. New cells are only made from existing cells.
Cells come in all shapes and sizes!
There are two types of cells: Prokaryotic Cells and Eukaryotic Cells
These are two distinct types of cells with STRUCTURAL differences. Prokaryotes Eukaryotes Bacteria Animal Plant
PROKARYOTE CELL A single celled organism that does not have a nucleus. Pro means before Karyon means nucleus
Traits of Prokaryotes: (pro-care-ee-ohts) 1. They do not have a nucleus, and their genetic material is not stored in the nucleus. 2. They have some organelles, but not many. 3. They are less complicated that eukaryotes. 4. All bacteria are prokaryotes.
PROKARYOTIC ORGANISM The first cells to appear on Earth were prokaryotic cells. A prokaryote is an organism made of a single prokaryotic cell. The earliest prokaryotes may have arisen more than 2.5 billion years ago.
Bacteria may be small but they are powerful! During the 14 th century, 25% or ¼ of Europe was killed by a killed by a bacteria called the Bubonic Plague, also called Black Death. This bacteria was spread through fleas and rodents.
The most recent international incident involving the alleged use of biological weapons happened in Syria on August 21, 2013 during which hundreds of people were killed including women and children. DAVAO CITY--The NPA bandits have employed bioterrorism in its attacks against military and civilian targets, latest military records show. He said that the shrapnel used by the NPA on their bombs were intentionally contaminated with bacteria in order to further improve its lethality. Enterobacter Cloacae and Streptococcus Agalacteiae
But at the same time we need bacteria to live! Bacteria are decomposers and without them all other organisms would not be able to survive. We use bacteria in our digestive system to help digest our food. There are approximately ten times as many bacterial cells as human cells in the human body! We could not make cheese or yogurt without bacteria.
EUKARYOTE CELL A more complex cell with a nucleus and many organelles. Eu means true Karyon means nucleus
EUKARYOTIC ORGANISMS Eukaryotes are organisms made of one or more eukaryotic cells. The earliest eukaryotes, like the first prokaryotes, were single-celled organisms. They arose about 1 billion years later than the earliest prokaryotes. Later, multicellular eukaryotes arose. Every type of multicellular organism that exists is made up of eukaryotic cells.
TRAITS OF EUKARYOTES: (you-care-ee-othts) 1. They all have a nucleus where the genetic material of the cell is stored. 2. They have many organelles that work together to help the cell function.
MORE TRAITS OF EUKARYOTES: (you-care-ee-othts) > Eukaryotic cells are much more complex then prokaryotic cells. > They can be just one cell or can make up more complex multi-cellular organisms. > All plants, animals, fungi, and protists are eukaryotic cells.
Think Pair - Share What do you think is the main difference between a prokaryotic cell and a eukaryotic cell?
The NUCLEUS! Prokaryotic cells do not have a nucleus and eukaryotic cells do have a nucleus. This allows eukaryotic cells to make multi-cellular organisms and perform more complex functions.
PROKARYOTIC Do not have structures surrounded by membranes Few internal structures One-celled organisms, Bacteria http://library.thinkquest.org/c004535/prokaryotic_cells.html
EUKARYOTIC Contain organelles surrounded by membranes Most living organisms Plant Animal http://library.thinkquest.org/c004535/eukaryotic_cells.html
ANIMAL and PLANT CELLS
Cell Differentiation Each kind of cell has a DIFFERENT job to do it is specialized. I am a heart cell! I am a skin cell I m a Prison Cell!
http://web.jjay.cuny.edu/~acarpi/nsc/images/cell.gif Cell
CELL PARTS Organelles
An organelle is a membrane-bound structure that carries out specific activities for the cell.
Surrounding the Cell
CELL MEMBRANE Flexible and thin covering, protects cells Outer membrane of cell that controls movement in and out of the cell Double layer http://library.thinkquest.org/12413/structures.html
CELL WALL Most commonly found in plant cells & bacteria Made up of cellulose for plants. Supports & protects cells http://library.thinkquest.org/12413/structures.html
Inside the Cell
NUCLEUS Largest organelle Directs cell activities Separated from cytoplasm by nuclear membrane Contains genetic material - DNA
NUCLEAR MEMBRANE Surrounds nucleus Made of two layers Openings allow material to enter and leave nucleus http://library.thinkquest.org/12413/structures.html
CHROMOSOMES Found in the nucleus Made of DNA Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html
NUCLEOLUS Small dark area Inside nucleus Contains RNA to build proteins It is responsible for making ribosomes. http://library.thinkquest.org/12413/structures.html
Gel-like mixture CYTOPLASM (not an organelle - but important) Surrounded by cell membrane Contains hereditary material All organelles reside (live and float around in) the cytoplasm.
ENDOPLASMIC RETICULUM http://library.thinkquest.org/12413/structures.html Moves materials around in cell Smooth type: lacks ribosomes Rough type ribosomes embedded in surface
Smooth Endoplasmic Reticulum (SER) Transports materials throughout the cell. It synthesizes lipids, phospholipids, and steroids. Cells which secrete these products,
Rough Endoplasmic Reticulum (RER) Covered with ribosomes. Produces proteins. works in concert with the golgi complex to target new proteins to their proper destinations.
Each cell contains thousands RIBOSOMES Synthesizes proteins Present in the cytoplasm. Present with Rough ER. No membrane present.. (not an organelle - but important) http://library.thinkquest.org/12413/structures.html
MITOCHONDRIA Produces energy through chemical reactions breaking down fats & carbohydrates A bean shaped organelle that controls level of water and other materials in cell Recycles and decomposes proteins, fats, and carbohydrates http://library.thinkquest.org/12413/structures.html
VESICLES It is a small sac/ bubble that surrounds material to be moved into or out of a cell
LYSOSOME Lysosomes (lys = split, some = body) Has a lot of enzymes. Digestive 'plant' for excess or worn-out cell parts, food particles and invading viruses or bacteria. Transports undigested material to cell membrane for removal Cell breaks down if lysosome explodes "Suicide Cells" http://library.thinkquest.org/12413/structures.html the cell's recycling compartment.
Membrane-bound sacs for storage, digestion, and waste removal A vesicle containing water solution Help plants maintain shape http://library.thinkquest.org/12413/structures.html VACUOLES
Central Vacuole (Plant Cell Only) Most plant cells have one large one. Filled w/ fluid. Helps maintains turgor pressure and shape of cell.
GOLGI BODIES http://library.thinkquest.org/12413/structures.html separates and packages proteins for export. Move materials within and out the cell (vesicles) produces cell membranes and lysosomes. The Golgi apparatus are stacks of membranecovered sacs.
CHLOROPLAST Usually found in plant cells Contains green chlorophyll Where photosynthesis takes place http://library.thinkquest.org/12413/structures.html
CENTRIOLE a) collections of microtubules (9 triplets) b) found in pairs. 1 pair = centrosome. c) Separate chromosomes