Happy New Year!

Merry Christmas!

The Arctic Tundra Ecosystem

The Arctic tundra is a flat, cold desert in which the temperatures can go down to -34 degrees and usually do not go higher than 7 degrees Celsius. The tundra gets about 15 to 25 centimeters of rain every year. Despite the lack of rain, the tundra has some producers, such as lichen, moss, shrubs, and flowers. There are almost no trees because the soil freezes 25-90 centimeters below the surface year-round, preventing them from growing.

Most of the consumers that live in the tundra do not live year-round, but some of them do, like the wolf and the brown bear. The animals that live year-round usually hibernate and come out during the 2 or 3 months when the tundra is not covered in snow. Most of the animals are primary consumers, like the arctic hare and the lemming, but the snowy owl, the Arctic fox, and other animals are secondary consumers. There are not a lot of decomposers in the tundra, but lichen, mushrooms, and other fungi and bacteria grow there.

Works Cited:

http://www.brainpop.com/science/earthsystem/tundra/

http://ths.sps.lane.edu/biomes/tundra4/tundra4.html

http://www.cotf.edu/ete/modules/msese/earthsysflr/tundraA.html

https://web.duke.edu/nicholas/bio217/spring2010/kommaraju/newarctic.htm

Viruses and Vaccines

     Viruses are tiny particles that are made up of DNA or RNA, a protein coating, and sometimes a fatty membrane. They cannot reproduce themselves, so they use an organism to do it for them. Viruses do this by attaching themselves to a cell in the organism and inject the virus DNA into the cell. It is fooled into replicating the DNA and making the protein coatings, which will combine to form new viruses. The new viruses then exit the cell by exocytosis or by bursting out of the cell and go on to infect other cells. Viruses can also mutate into different strains so the immune system doesn’t recognize it.

     Before vaccines were invented, many people died of diseases caused by viruses such as smallpox, mumps, and polio. 1 out of 3 children died before they were 10 years old because of these diseases. In 1796, Edward Jenner noticed that some milkmaids did not get smallpox, but they did get cowpox. Jenner wondered if smallpox and cowpox were related. He then did an experiment in which he scraped a sore from a milkmaid’s arm and then injected the sore into an eight year old boy’s arm. Jenner then injected some of the smallpox virus into the boy. The boy didn’t get infected! Jenner did this with 20 other people, all of whom did not get smallpox.

     Other doctors tried to do the same thing with different diseases. One doctor injected rabbits with polio, crushed up their spines, and injected the spines into people to prevent polio. It worked, but over time the people developed other problems caused by the injection. After this, doctors stopped using animals to cure diseases.

     A large percentage of people need to be vaccinated in order for the disease to be wiped out. This is why you need to get vaccinated. Washing your hands and general hygiene can also help to prevent disease.

Happy Thanksgiving!

Transporting things across a membrane

  

     There are four types of transportation of things across a membrane: Diffusion, active transport, osmosis, and endocytosis. Diffusion is when the molecules bump into each other and spread out, and sometimes one of the molecules gets bumped into a cell. The places that do not have a lot of molecules in them have a low concentration, the places that have a lot of molecules have a high concentration, and the difference between them is called the concentration gradient. An example of diffusion is: if you put a drop of food coloring in a cylinder of water, you will see that the food coloring spreads out to the places where there is a low concentration. After a couple hours the food coloring will have completely diffused through all of the water in the cylinder.

     A molecule in active transport, however, can go either way with the concentration gradient. It uses proteins to bring molecules in and out, and only one kind of molecule can fit into a certain protein. Active transport uses ATP to function, unlike osmosis.

     Osmosis is when water flows freely in and out of the cell. If sugar or salt is present outside the cell, the water will go towards it, therefore lowering the concentration gradient of the cell. Because they are both polar, the water will be attracted to the sugar or salt.

     Endocytosis is when a big molecule is surrounded by the cell membrane. It then pinches off the membrane and forms a package called a vesicle or a vacuole. White blood cells do this with viruses and bacteria, and amoeba do this also with food. A similar type of transportation is exocytosis, which is when the cell pushes large molecules out. Both use ATP.

Photo courtesy of www.hartnell.edu

Salmon Mating and Reproduction

     Salmon swim to the place they were born, and can encounter many obstacles along the way, such as dams, waterfalls and bears. Once a female finds a place, she fans her tail against the pebbles on the riverbed, making a kind of nest for her eggs.  While she is doing this, some males will gather near her, and she permits one to stay with her, and they release egg and sperm into the nest. Then the female buries the eggs and guards the place until she dies.

     Before the egg and sperm are formed in the salmon, the DNA in the diploid cells undergo segregation, also called meiosis, which is when the chromosomes separate into halves. The diploid cells now have half the number of chromosomes a regular cell has. When the egg and sperm are developed and the salmon release them, a sperm penetrates the egg, and recombination happens, which is when the chromosomes recombine to form the first set of chromosomes in what will be the new salmon.

Works Cited

"Fish and Wildlife Service." Fish and Wildlife Service. N.p., n.d. Web. 05 Nov. 2013.

"How Do Fish Reproduce?" How Do Fish Reproduce? N.p., n.d. Web. 05 Nov. 2013.

"Kids' Species Information, Delta Smelt." Kids' Species Information, Delta Smelt. N.p., n.d. Web. 05 Nov. 2013.

"Login." Login. N.p., n.d. Web. 05 Nov. 2013.

"Salmon Run." Wikipedia. Wikimedia Foundation, 26 Oct. 2013. Web. 05 Nov. 2013.

"Salmon Spawning." YouTube. YouTube, 01 May 2011. Web. 05 Nov. 2013.

"Salmonidae." Wikipedia. Wikimedia Foundation, 11 Feb. 2013. Web. 05 Nov. 2013.

"Trout Species - TroutJournal.com." Trout Species - TroutJournal.com. N.p., n.d. Web. 05 Nov. 2013.

Happy Back-to-Homeschool!

Summer Field Trip: Metropolitan Museum of Art

Today we went on a field trip to the Metropolitan Museum of Art. We toured the ancient Greece and Rome exhibits, then saw the exhibits Arms and Armor, Arts of Africa, Oceania, and the Americas, and Musical Instruments.

We spent the most time in the Greece and Rome exhibits since we just finished studying Greece and are now on Rome. However, my favorite exhibit of the day was Arts of Africa, Oceania, and the Americas.

Summer Homeschool 2013!

Here are some of the subjects we will explore this summer:

Online math practice
Literature
French
Ancient Greece
Arts and Crafts
Sewing
Music
Swimming
Hiking
Community Service/Volunteering

Happy Summer!

DNA and Heredity

Why don't a black cat and a white cat have a gray cat? It has to do with DNA and heredity. DNA stands for Deoxyribonucleic Acid and is a double helix structure made out of 4 amino acids: Adenine, Thymine, Guanine, and Cytosine. DNA holds the instructions for life and is stored in things called chromosomes. Humans have 46 pairs of chromosomes in almost every cell. When parents have offspring, that offspring gets 23 pairs from each parent.

 Let us go back to the question: Why don't a black cat and a white cat have a gray cat? Let's say the cats are purebred. That means the black cat only has genes for black fur and the white cat only has genes for white cat fur. A gene is a unit of heredity. The offspring would have black fur, because the gene for black is dominant. The offspring didn't get white fur because white fur is a recessive trait. The offspring can only have the recessive trait if both parents have that trait.

Daddy- Long- Legs by Jean Webster

Daddy- Long- Legs by Jean Webster is about a 17 year old orphan named Judy Abbot who lives at the John Grier Home.  She is sent to college by an anonymous benefactor, and he will pay for her education under the condition that she write to him every month about what she is learning. For instance, she did a newspaper- like letter about Hannibal and the Punic Wars. She gives the benefactor the nickname Daddy- Long- Legs because she got a glimpse of him and saw that he had long legs.

At college Judy meets two girls: the amiable Sallie McBride and the stuck- up Julia Pendleton. They become friends and have adventures together, like when they walked up a hill at the crack of dawn to see the sun rise. She also meets Julia’s uncle, Jervis Pendleton, who is the exact opposite of Julia.

In the summer, Judy goes to a farm called Lock Willow, at the request of Daddy- Long- Legs. There she has a lot of adventures, such as fishing with Jervis Pendleton.

  
I would highly recommend this book. It was really funny, and I liked it a lot. I also liked how the book ended.

Electrolysis of water

The electrolysis of water happens when water (H2O) gets separated into oxygen and hydrogen atoms. In order to do this, energy must be introduced in form of electricity. Usually, this cannot happen on its own. The video below shows this reaction. We connected a 9-volt battery to two wires to supply the energy. The bubbles on the black wire are hydrogen bubbles, and the bubbles on the red wire are oxygen.

 

The Girl Who Circumnavigated Fairyland in a Ship of Her Own Making

The Girl Who Circumnavigated Fairyland in a Ship of Her Own Making is about a girl named September who lives in Omaha, Nebraska. She goes with the Green Wind, who takes her to Fairyland, where she meets a Wyvern named A-through-L, and they have adventures together.

This book is awesome. I love the characters and the plot is good, but it is sad at some parts, such as when the Marquess locks up A-Through-L and Saturday, the Marid, and September has to circumnavigate Fairyland to rescue them.  My favorite part is when Ell (A-through-L’s nickname) shakes persimmons from a tree and September eats them.

This book has a lot of creative characters in it, such as Lye, the soap golem, and Goodbye, the witch. My favorite character was Gleam, the 100-year-old lamp. She comforted September when September was thrown in a well by Hannibal, the pair of sandals. He was my least favorite character. All in all, it was a good book.

Happy New Year!