February 22, 2013

February 24, 2013

February 24, 2013

I hope everyone was able to enjoy their weekend.  I know ours was a busy one with lots of family time!

Events of the Past Week

Monday - No School.  Happy President's Day!

Tuesday - We began the Mendelian Genetics portion of our genetics unit on Tuesday.  The students were introduced to monohybrid crosses involving simple dominance and incomplete dominance, as well as a type of experiment called a testcross.  For homework, the students completed Problem Set 1.

Wednesday - Problem Set 1 was collected at the beginning of class.  We then spent a little time talking about some common human traits controlled by one pair of genes, such as having a widow's peak, a hitch-hiker's thumb, a longer second toe than big toe, or the ability to roll your tongue.  After investigating some of our own traits, we then learned how to perform a dihybrid cross.  The dihybrid cross is used to predict the outcome of a cross involving two different traits at the same time.  For homework, the students were given Problem Set 2.

Thursday - We learned about X-linked traits on Thursday.  Examples of common X-linked traits are red-green colorblindness, hemophilia, and Duchenne muscular dystrophy.  These are all traits whose genes are located on the X chromosome.  This means that males are more likely to have them because they only inherit one gene for any X-linked trait, meaning that a recessive gene cannot be hidden.  The students then worked on the first 8 problems for Problem Set 3, which were to be completed for homework.

Friday - The students began class by taking a prequiz assessment to see how ready they were for their quiz on Monday, which will cover monohybrid crosses, dihybrid crosses, simple dominance, incomplete dominance, X-linked traits, pedigrees, and testcrosses.  After the prequiz, the students were introduced to pedigrees, which are basically family trees.  After being introduced to pedigrees and how to interpret them, the students were given time to work on problems 9 and 10 from Problem Set 3, which are to be done for Monday.

Upcoming Events

Monday - The students will take their first genetics quiz, which will consist of 15 multiple choice problems and one, 3 part written problem.  After the quiz, the students will take a look at the pedigree for Queen Victoria's family to learn how an X-linked recessive trait caused the Russian Revolution and the rise of communism!  Afterwards we will listen to the song "I'm My Own Grandpa" by Ray Stevens and try to draw a pedigree of the family described in the song.  At the end of class I will take some time to explain the requirements of the lab report the students will be writing using the data from their fruit fly computer simulation that was run at the beginning of our unit.

Tuesday - We will learn about traits for which more than one allele exists in the population on Tuesday (such as blood types).  We will also learn about a type of inheritance called codominance (not to be confused with incomplete dominance) at the same time when we study blood types that day.  Homework will be to complete numbers 1-7 on Problem Set 4.

Wednesday - The students will be introduced to polygenic inheritance (traits controlled by more than one pair of genes, such as height and skin color).  For homework they will complete questions 9 and 10 in Problem Set 4.  Question 8 will be skipped as it covers a topic that we will learn about during our evolution unit.

Thursday - Problem Set 4 will be collected.  The students will then be introduced to the concept of epistasis, in which one pair of genes controls the expression of another set of genes.  We will look at coat color in labrador retrievers as our example.  For homework there will be worksheet with 2 different epistasis problems.

Friday - We will review everything we learned during the course of the week in preparation for our second genetics quiz on Monday.  If there is any time remaining after our review, the students can use that time to work on their fruit fly reports with their groups.  Homework will be to study for the quiz on Monday.

Graba Geek of the Week

This week's Geek of the Week goes to Madelyn Ziaj, who earned excellent grades on both Problem Set 1 and Problem Set 2, and was not afraid to send me questions via e-mail to help her when she was confused on anything in the homework.  Keep up the hard work, Madelyn!

February 17, 2013

February 17, 2013

February 17, 2013

We have been very busy in class this past week collecting data that will be used in our fruit fly lab reports that will be due near the end of our genetics unit.

Events of the Past Week

Monday - Class began with an explanation of the differences between the formation of sperm in males (spermatogenesis) and the formation of eggs in females (oogenesis).  We then spent some time reviewing our meiosis material in preparation for our meiosis quiz on Tuesday.  Homework was to study for the meiosis quiz that we took on Tuesday.

Tuesday - Periods were shortened on Tuesday due to the Late Start Day.  The quiz took most of the class period, but there was time to introduce our fruit fly (Drosophila melanogaster, for you science geeks out there) computer software.  The students learned how to use the program, and were given their groups for the project.  I attempted to group students according to their math levels and grades, such that each group should have at least one strong math student in it.  Genetics is a very mathematically based unit, and this particular project requires quite a bit of math skill, so this seems to be the best way for me to group students.  I created the groups for all four of my classes.

Wednesday - The students began using the computer program to collect data for their projects.  They were given two different fruit flies, each with a different mutation, to breed.  They then counted 100 of their offspring, classifying them as male or female, and also looking for any mutations in the flies.

Thursday - The students continued collecting data, first by breeding 2 of the offspring from their first generation and counting 200 of their offspring, then by breeding two different males and females and counting them through two generations.

Friday - We finished collecting data, and the students then handed their data over to me so that I have a copy of it.  This will prevent them from changing their data later in the genetics unit after they have determined how their traits are inherited.  Class periods were only 28 minutes on Friday due to an early dismissal.

Upcoming Events

Monday - No school - PRESIDENT'S DAY

Tuesday - Students will be introduced to how to predict the results of a breeding between two individuals where we look at only one trait being passed down to the next generation.  These types of problems are called "monohybrid" crosses.  They will also be introduced to a special type of cross called a "testcross", and a type of inheritance called "incomplete dominance."  Homework will be to complete Problem Set 1 on a separate piece of paper.

Wednesday - Problem Set 1 will be collected.  5 of the 10 problems will be graded.  Each problem that is graded will be worth 2 points, with one point coming from the work that is shown being accurate, and the other point coming from having the correct answer.  If an answer is given with no work, then no credit will be given for the problem.  Since it is homework, without any work being shown, I have no way of knowing if the student just asked for the answers from a friend, or if they actually took the time to do the work.

After collecting Problem Set 1, the students will be introduced to "dihybrid crosses," where they will be determining the expected outcomes of a cross between two individuals where we look at two traits being passed down at the same time to the next generation.  Homework will be to complete Problem Set 2 on a separate piece of paper.

Thursday - Problem Set 2 will be collected from the students, with 5 of those questions being graded at 2 points each.  After being collected, the students will be given the opportunity to ask any questions they may have from Problem Set 2.

We will then be looking at traits that are carried on the sex chromosomes (specifically, the X-chromosome). This type of inheritance is called X-linked, or sometimes sex-linked, inheritance.  The students will then be given Problem Set 3, and will complete up through and including number 7 on a separate piece of paper.  Any problems not finished will be completed for homework

Friday - At the beginning of class, the students will be taking their first genetics quiz.  The quiz will cover the topics of monohybrid crosses, incomplete dominance, and test crosses.  In addition, the students will be expected to know any new vocabulary learned during the course of the week. 

When everone finishes the quiz, we will learn about pedigrees.  Pedigrees are family trees that trace the inheritance of a particular trait through a family.  After looking at a few pedigrees, the students and I will look at the inheritance of hemophilia in Queen Victoria's descendants.  We will look at how the inheritance of this X-linked recessive trait led to the rise of communism and the Cold War between the United States and Russia (we might be stretching it a little bit, but we'll have fun with it)!  Homework will be to complete the worksheet "Human Pedigree Genetics" on a separate piece of paper.

Graba Geek of the Week

This week's Geek of the Week is Matt McCabe, who earned a perfect score on his meiosis quiz in the beginning of the week.  Fantastic job, Matt!