Friday, February 27, 2009

The Bolsa Chica Project!

As you may know I am involved with a group called the Bolsa Chica Land Trust. Our goals is the preservation, restoration, and maintenance of the entire Bolsa Chica ecosystem. We have a plan to raise 5 million dollars in ONE DAY- EARTH DAY 2009. Check out the video to see how:

Did you like the video? If so sign up at Youtube, and comment on it and rate it! After signing in at Youtube just search "Bolsa Chica Project" to get to the video. You can also subscribe to get updates as there are more videos planned. Please share the video with your friends! This is a great way to spread our message and generate interest in the video.

Thursday, February 26, 2009

More review questions for second exam

Genetic Engineering

1. What are restriction enzymes?
2. What kind of cells have restriction enzymes, and what is the purpose of these enzymes in the cell?
3. What is a plasmid?
4. How are plasmids used in genetic engineering?
5. Why does human DNA work in a bacterial cell?
6. What is gene therapy? Thursday, September 25, 2008

DNA Review Questions

1. Describe the structure of the DNA molecule

2. If the sequence of bases on one stand of the molecule is AAC TGC CCG, what is the sequence on the complemetary strand?

3. During DNA replication, what enzyme breaks the hydrogen bonds between the base pairs, and what enzyme matches up nucleotides to the existing ones on the parent strand of DNA?

4. Why is this type of replication called Semi Conservative?

5. How is RNA different from DNA?

6. The production of messenger RNA from DNA is called ________, and this happens in the __________ of the cell.

7. The parts of the mRNA molecules which are edited out before RNA reaches the cytoplasm are called __________

8. mRNA gets a cap and a tail prior to being read by the ribosome. What is the function of the cap and tail?

9. If the DNA strand being copied had this sequence: ACT GGC ATA CTA what would the sequence of the mRNA be?

10. The function of transfer RNA is ?

11. What is the name of the enzyme that produces RNA from DNA?

12. If the sequence of DNA is the same in your body cells, why are all cells not the same?

13. The DNA in you, an earthworm, and a fungus is the same. So why are you a human and not an earthworm?

14. What is an anti-codon and where is it found?

15. The protein synthesis process that occurs at the ribosome is called _____________

16. What is a stop codon?

Mitosis and Meiosis Review Questions

1. If a cell has 8 chromosomes and does mitosis, how many cells will be made, and how many chromosomes will each cell have?

2. If a cell has 8 chromosomes and does meiosis to make sperm cells, how many cells will be made, and how many chromosomes will each cell have?

3. Mitosis creates cells which are ________, while meiosis makes cells which are _____.

4. What are homologous chromosomes?

5. What are sister chromatids?

6. What is crossing over, and during which process, (mitosis or meiosis) does it occur?

7. Why is crossing over important?

8. During __________ of mitosis sister chromatids separate.

9. During _________ of meiosis homologous pairs of chromosomes separate, but during ____________ of meiosis sister chromatids separate.

10. In meiosis, typically four sperm cells are made, but meiosis only makes one large egg cell. Why?

Wednesday, February 18, 2009

Massive Cache of Fossils Unearthed at La Brea Tar Pits

Scientists at the La Brea Tar Pits in Los Angeles are in the process of sorting through a massive collection of fossils removed from near the LA County Museum of Art which is next to the tar pits. 23 crate loads of deposits were removed with a crane prior to the site being readied for an underground parking garage.

Since the summer of 2006, scientists working at the Page Museum have been sorting through the deposits. One remarkable find is that of an intact Colombian mammoth ( named Zed) which is estimated to be about 40,000 years old.

Other fossils include American lion bones, horses, bison, coyotes, lynx, ground sloths and dire wolves. The deposits are being uncovered by the staff at the George Page Museum. The lab where this is happening is surrounded by windows, so if you want to go watch take a visit to the Page Museum. You can visit the Museum's webpage here.

To read more and see a picture of Zed's pelvis, click here. KNX news radio also has pictures on their website here

Friday, February 13, 2009

Valentines Advice from Sage Grouse

Gail Patricelli from the University of California at Davis has discovered that to impress the ladies male sage grouse need more than a fancy dance and a big tail. The most successful males also responded to the behavior of females in subtle ways.

Groups of male sage grouse strut, inflate air sacs and make booming sounds in a complicated dance on a dancing area called a lek, while they compete for the attention of the females. Dr. Patricelli studied these behaviors with a camera ("called the fembot") disguised as female grouse. She found the few males which were successful in mating were those who were the most responsive to signals from the females.

So gentlemen, take a lesson from the sage grouse, and try a little sensitivity.
Take a look at the sage grouse display and the "Fembot" below

Post Darwin: Homer Simpson evolves

One of my friends posted this on his blog, and it is too good not to share with all of you. Enjoy

Thursday, February 12, 2009

Happy Birthday Mr. Darwin

What concepts did Darwin develop, and why were they so revolutionary?

Species can change- Living things are not fixed, but can change over many generations.

Common Descent—All life on Earth shares a common ancestry. Yes, even humans.
Drawing from one of Darwin's notebooks

Gradualism--The change of a species takes a long time.
Marine Iguana, Isabela Island, Galapagos

Land Iguana, North Seymour Island, Galapagos.
The land iguana and marine iguana evolved from a common ancestor, probably an iguana from the mainland of South America.

Natural selection
Certain randomly acquired traits are helpful.

Individuals with helpful traits survive longer, have more offspring, so over time these traits increase in a

Nature selects which traits are beneficial, and which are not.

Small ground finch, San Cristobal Island, Galapagos

Medium ground finch, San Cristobal Island, Galapagos.

The main difference between "Darwin's finches" is the size and shape of their bills. What advantage would their be to an individual with a beak like the one found on the medium ground finch? What about the the bill found on the small ground finch?

Others prior to Darwin had suggested species may have changed over time, and were not fixed. However, Darwin was the the first to suggest a logical mechanism (natural selection) though which these changes occurred.

Happy Darwin Day

Have you googled today? If you have then you might have noticed the tribute to Mr. Dawin. I see some of "Darwin's finches", from the Galapagos Islands in the illustration. When Darwin collected the birds, he actually thought he had a mix of finches, blackbirds, and warblers only to discover after the birds were examined back in England, by ornithogist John Gould that indeed they were all finches.

The bird that really go his attenion in the Galapgos were the mockingbirds on different islands.

Darwin wrote in The Voyage of the Beagle:
"My attention was first thoroughly aroused, by comparing together the numerous specimens, shot by myself and several other parties on board, of the mocking-thrushes, when, to my astonishment, I discovered that all those from Charles Island belonged to one species (Mimus trifasciatus); all from Albemarle Island to M. parvulus; and all from James and Chatham Islands (between which the other two islands are situated, as connecting links) belonged to M. melanotis."

He also noticed that the different species did not occur together on the various islands he visited and he wondered why this was...

Wednesday, February 11, 2009

Darwin Day Special: Evolution of Lice

Pubic louse (Pthirus pubis)

Biologists wonder about all kinds of things. Dr. Robert Weiss for example wondered why humans are parasitized by two different species of lice, head lice (Pediculus humanus) and pubic lice (Pthirus pubis commonly called crabs). What would have caused this separation of lice into two species, both of which occupy different habitats on the body? After all our ancestors were hairy all over so why specialize in different areas of the body?

Head louse (Pediculus humanus)

It turns out Dr. Weiss discovered pubic lice that infect humans evolved from lice found on gorillas (Pthirus gorillae). The two species of lice diverged about 3.3 million years ago according to David Reed from the University of Florida, however humans and gorillas diverged earlier, about 7 million years ago. Dr. Reed's work also demonstrated that human head lice probably came from our hominid ancestors. Dr. Weiss hypothesizes that later our human ancestors caught the pubic lice ancestor from the gorillas while hunting and butchering them. This close contact would have allowed the gorilla lice to jump onto our ancestors, burrow in and start feeding!

Weiss et al. Apes, lice and prehistory. Journal of Biology, 2009; 8 (2): 20 DOI: 10.1186/jbiol114

Monday, February 9, 2009

Darwin Day Special: Links

I've come across a couple of websites of interest to those of you who wish to learn a bit more about Charles Darwin.

This site by David Leff, has an amazing amount of information about Darwin the man as well as Darwin the scientist.

The complete works of Charles Darwin are online. This is a wonderful resource for exploring some of his letters, books and other publications

Sunday, February 8, 2009

Darwin Day Special: More from Sir David Attenborough

This is a clip from the trailer of the new series, and a bit of a preview in which Sir David talks about one of the most compelling parts of Darwin's theory-that is that we, as humans, are not separate from the natural world, but part of it.

Saturday, February 7, 2009

Darwin Day Special: from Dinos to Turkeys

Darwin Day Special: National Geographic's new show "Morphed"

National Geographic is broadcasting a series of shows this week as part of a new series called "Morphed" You can visit the website here, and watch short video segments about whale evolution, the evolution from dinosaur to birds, and bear evolution.

I watched the video clips, and did cringe a bit when in the one about the transition ancestors of whales underwent from land animals to marine animals, the narrator talks about a paleontologist "going after the biggest fish in the sea." Whales, after all are mammals like you and me, not fish.

There is a great deal of information on the website including a short preview of a program on Darwin's notebooks that includes a re-enactment of Darwin in Patagonia.

The series starts broadcasting tomorrow.

Friday, February 6, 2009

Darwin Day Feb. 12 Happy 200th Birthday to Charles Dawin

In honor of the 200th anniversary of the birth of Charles Darwin, I will be posting information about evolution over the next week or so. Remember, come to the Darwin Day presentation on Feb 10 at 11 AM in Science Lecture hall 201.

Darwin Day Special: OK so flies evolve... but what about people

In my last post I wrote about work that demonstrates the evolution of fruit flies over a period of a couple of hundred years. This kind of research shows us we can look around at the living world and see evidence that evolution is happening around us, but what about us? Are there things in our bodies that hint at our evolutionary past?

Why do we have parts in our bodies that don't function? Why do we have things like goose bumps, which don't do anything for us? Structures present in an organism, but not functional (even though these structures may function in other organisms) are called vestigial structures.

What is responsible for the construction of vestigial structures during development? Sequences of DNA.
Where does DNA come from? Our ancestors......

For a list of vestigial structures found in humans click here.

Darwin Day Special: Flies that live on apples providing more clues to formation of new species

Biologists from Notre Dame, Michiagan State and the University of Florida have just published an article in which they describe how the introduction of apple trees to the US 400 years ago has affected the evolution of a type of fruit fly AND the parasitic wasp that feeds on the maggots of the fly.

Prior to the presence of apple trees in the US, these flies Rhagoletis pomonella found mates, and laid eggs on the fruit of the hawthorn tree. In the 1800's some of these flies began going to apples to mate and lay their eggs instead. These flies have now become genetically different from the flies that still visit the hawthorn fruit.

This is an example of how new species can form. Over time mutations, natural selection and other mechanisms of evolution affect the two fly population in different ways, until they are so genetically different they become species.

What is really interesting to me is how fast this happens, and that the same kind of speciation is also happening to the parasitic wasps that feed on the maggots of the flies. This is an example of co-evolution. Co-evolution happens when the evolution of one species affects the evolution of another.

So you see, it is not necessary to go off to some exotic place to study evolution. The process of evolution is happening all around us. Articles like this make me wonder what kind of evolution could be going on right here at the college?

Forbes et al. Sequential Sympatric Speciation Across Trophic Levels. Science, 6 February 2009: 776-779 DOI: 10.1126/science.1166981

Wednesday, February 4, 2009

Darwin Day Special: Discovery of new transitional fossil of whales announced

Boy oh boy, give me a little free time and look at all the posts I can publish! I'll leave the news about the giant fossil snake, Titanaboa cerrejonensis, for you to find on your own by the way.

Philip Gingerich and colleagues have just published an article describing fossils of whale ancestors they discovered in Pakistan. They found two adults, one male and one female, and as they uncovered the fossil of the female whale they discovered a fetus inside. These early whale ancestors still had legs, and most likely gave birth on land.

The fetus had teeth and was facing head first toward the birth canal which is why the researchers believe the animals gave birth on land. As you can imagine, heading into the water head first to take one’s first gulp of air would be disastrous for the baby. Modern whales are born tail first.

The well formed teeth suggest the young were very precocious, and ready to feed soon after birth.

The name of this 45 million year old ancestral whale fossil is Maiacetus inuus. You can read the article by Gingerich and colleagues here as well as see photos and drawings of the fossils.

Darwin Day Special: 635 Million year old Steroids

Scientists at the University of California at Riverside working with scientists at MIT have have discovered massive amounts of steroids in sediments that are 635 million years old. These steroids were made by sponges, and are the earliest evidence of animal life discovered to date!

You can read more about this discovery here

DNA a "bar code" for plants?

Last year researchers from the Royal Botanical Gardens in England in collaboration with researchers at the University of Johannesburg and the University of Costa Rica, discovered a gene that could be used to readily identify plant specimens. This gene called the matK gene is different in different plant species, but has the same DNA sequence in plants of the same species.

This gene could be useful to identify different plant species which look very similar, or to identify plants which have been pulverized for use in medicines or teas.

The use of this gene will also make it possible to identify endangered plant specimens more easily, especially those which physically resemble less rare plants. It could also be used for example, by customs agents trying to detect the illegal importation of rare or endangered plants from other countries.

To read more about this discovery click here

Bio 120 review questions for the first exam

Hi Folks,
These questions appear elsewhere on the blog, but I have brought them up in a current post so they are easy to find.

1. What are the building blocks of carbohydrates?
2. What is the difference between a saturated and unsaturated fatty acid?
3. Why is the shape of an enzyme important to the function of the enzyme?
4. At what level of complexity do proteins usually become functional?
5. What makes up a nucleotide?
6. What bond forms between amino acids as they react to form proteins?
7. How is the function of carbohydrates different in plants and animals?
8. What is the name of the carbohydrate human cells use to store glucose?
9. Which of the macromolecules we discussed stores energy in the most efficient way?
10. What is the most common steroid in the body?

Here's some more questions for you to answer !
1. A cell must maintain an imbalance of sodium ions on either side of the membrane for it to function. What process would it most likely use of the ones we discussed today in class?
2. How are polar and non polar covalent bonds different?
3. What is a hydrogen bond, and why are these bonds important to life?
4. Oxygen has 8 electrons, with 6 in the outermost energy leve. Will this atom react?
5. How are ions formed?
6. A solution with a pH of 5 is how many times more acidic than a solution with a pH of 7?
7. What determines if an atom with react with another?
8. A plant cell in a hypertonic solution will under go _____________
9. An animal cell in a hypotonic solution may undergo _____________
10. A Paramecium can survive in fresh water without bursting. Why?

1. How are the mitochondria and chloroplasts similar?
2. Why do we think the mitochondria was once an independent organism?
3. Describe the plasma membrane. Include how a lipid membrane functions in a watery environment.
4. What role do the proteins in the plasma membrane play?
5. How is active transport different from diffusion and osmosis, and faciliated diffusion?
6. How is dialysis different from osmosis?
7. What affect would a hypertonic solution have on a cell?

How is a hypothesis different from a theory?
What are five characteristics of living things?
How are prokaryotic cells different from eukaryotics cells?
What can cyanobacteria do that the bacteria living in your mouth do not do?
How are archebacteria different from the bacteria living on your skin?
Describe briefly what organelles would be involved in making a protein and exporting it from the cell.
Give an example of two cell organelles working together to accomplish a task.
What organelle is found on the ER?
What is the function of lysosomes?
Where is the nucleolus?
What are the functions of the Golgi bodies?

Of the taxonomic groups listed below, which is the least inclusive group?
domain, species, family, genus

To which Kingdom do you belong?

Monday, February 2, 2009

David Attenborough and the Tree of Life

Another preview about the Tree of Life. This is a wonderful representation of the Tree of Life on Earth. It is a beautiful presentation, even if it does seem to leave out plants. Algae at least get a brief mention. Take a look!