February 2015 archive

Grade 9 variation and natural selection

Charles Darwin, Alfred Russell Wallace and their theory of Natural Selection:

Charles Darwin and Alfred Russell Wallace both discovered the process of natural selection independently, Darwin in 1837 and Wallace in 1858 as this 30 minute video shows.

Speciation:

Speciation is the formation of two species from one species.  Describe an example of speciation from one of our examples: Galapagos finches, giraffes or lizards.

Dogs, Wolves and Selective Breeding:

Where did dogs come from?  It is universally accepted by scientists that dogs came from wolves.  But were they selectively bred by humans or did they evolve from wolves into dogs?  These are  two competing hypotheses proposed by different scientists.  You will watch a video that presents the arguments.  You decide which is the best answer.

Here is an article about wolves, dogs and their diet and digestion.

Here is a model you can use to explain how Natural Selection works.

How does selective breeding of dogs help humans?

Has the selective breeding of dogs gone too far? Dogs That Changed the World, Part 2.  You will answer that question through a Criterion D assignment.  TSC here.

For this project you will need to choose a breed of dog as your main example. Find lists of breeds of:

working dogs  such as Herding dogs  or Guard dogs (scroll down to the bottom)  also hunting dogs or companion dogs, or just all dogs with a picture.  Very obscure breeds or ones without a clear purpose may be very hard to research well.

Once you choose a dog breed to focus on, please note your choice here. It would be best if everyone had a different breed of dog as their main choice.

Suggested timeline:

Feb 27 watch video on evolution of dogs from wolves (part 1) and take notes to answer question 1 (finish for HW)

Monday, March 2 watch dog video part 2 on selective breeding of dogs and take notes to answer section 3. Start research on chosen breed of dog for section 2.

We do not have class on Thursday March 5 but you could spend some time finishing your research during the entire week between classes.

Monday March 9 Complete section 4 and write the essay using your notes. Check your sources are in MLA format.

Thursday March 12 Turn completed essay in using Turnitin.com at start of class.

Organic chemistry Reactions

Here is a slide show with links to information on alkane and alkene reactions.

We will discuss some of this in class, but you will need to complete the notes for homework.

Here is the slide show part 2 of the organic reactions.

Here is a short version of most of the reactions you need to know and a couple you don’t. (Contains the upcoming HL only reactions as well.) Just FYI – knowing a bit more detail than this will be useful… so don’t be sad you spent longer on this than just writing the short cut version down.

Hey, soap makers! Take a look at the label on your shampoo bottles at home and see if you can recognize any ingredients. Then, take a look at this interactive from the Guardian (a UK news source) and find out a bit more about some of the ingredients. Here is a quote from the associated article that was expressing concern over exposure to unknown chemicals:

“While we wait for regulation, which will be slow in coming … consumers are left with two options: bone up on chemistry to better avoid or reduce exposure to certain chemicals or types of chemicals, and ask retailers to stock healthy products.”  YOU know which of these I am voting for (I added the italics)!

How many drops of water fit on a coin? Investigate surface tension and IMF in water

Here is the link to the TSC for this experiment.

The design for the experiment will be assessed on Monday. Please have it printed.

Use some background research to support your hypothesis.

One site that may be useful about surface tension of water is here. Here is another about salt dissolving in water. There is a link on the left of that second link about sugar as well. What ever you use, please cite in MLA format.