Marking Period 3: Biology

Pedigrees

The best pedigree in the world won't sell a lame race horse. Anon.

We can look at the characteristics of  ancestors to predict characteristics of offspring.  The pedigree tool is a useful way to predict passing of characteristics in live stock and in people.  This is useful to geneticists in predicting the likelyhood of genetic disease being passed to one's children.

Dominance: Simple Mendalian Genetics

Things aren't always what they seem.  You are only seeing part of me.  There is more than you could ever know behind the scenes. Francesca Battestelli

Mendel came up with the concept of dominant and reessive characteristics, but was limited by the pea chcracteristics hee was studying.  There is a little more to inheritance patterns that simple dominance.  This unit will explore some of the nuances of dominance as it pertains to oorganisms other than the pea Mendel relyed on.

 

Mendelian Genetics: An Introduction

The relationship between Genotype and Phenotype is rarely as simple as in the pea plant charateristics Mendel studied. Anon.

Gregor Mendel was able to determine the basic patterns of inheritance by observing how physical characteristics were passed from one generation of pea plant to another.  There were many limitations he had to overcome, not least of which was the mechanism for such inheritance.  He is considered the father of modern genetics for the ideas and models he proposed.

Punnett Squares: Mono-Hybrid Crosses

The 50-50-90 rule: anytime you have a 50-50 chance of getting something right, there's a 90% probability you'll get it wrong.  Andy Rooney

The characteristics of an individual are controlled by the combination of genes from two parents. It is important to recognize that not all combinations of genes are equally likely; in fact, we can predict the probability of any specific combiation using statistical methods.  Reginald C. Punnett developed a method to determine the statistical likelyhood of a particular outcome.  The elegance of this method is that we create a tabular summary of possible combinations of maternal allele's with paternal allele.  These tables can be used to examine the genotypic outcome probabilities of the offspring of a single trait (allele), or when crossing multiple traits.

Inheritance: The Concept

Genetics explains why you look like your father, and if you don't, why you should  Anon.

It is important that we realize how far we have come in such a short time.  It wasn't so long ago that we didn't know anything about the invisible world around us - the world of cells and microbes.  The development of the microscope opened up a whole new world to biologists, and allowed us to discover so much about life.

Incomplete & Co-Dominance 

Genetics play a huge part in who we are. But we also have free will.  Aidan Quinn

We can look at the characteristics of  ancestors to predict characteristics of offspring.  The pedigree tool is a useful way to predict passing of characteristics in live stock and in people.  This is useful to geneticists in predicting the likelyhood of genetic disease being passed to one's children.

Sex-Linked Traits

I inherited a pound from my British uncle. I’d have rather gotten a dollar, because what do I want with an animal shelter?  George Washington.  Jarod Kintz

We can look at the characteristics of  ancestors to predict characteristics of offspring.  The pedigree tool is a useful way to predict passing of characteristics in live stock and in people.  This is useful to geneticists in predicting the likelyhood of genetic disease being passed to one's children.

Punnett Squares: Di-Hybrid Crosses

When you have eliminated the impossible, what ever remains, however improbable, must be the truth.George Washington. Sir Arther Conan Doyle; The Sign of Four

We can look at the characteristics of  ancestors to predict characteristics of offspring.  The pedigree tool is a useful way to predict passing of characteristics in live stock and in people.  This is useful to geneticists in predicting the likelyhood of genetic disease being passed to one's children.

Karyotypes 

If you share a common ancestor with somebody, you're related to them. It doesn't mean that you're going to invite them to the family reunion, but it means that you share DNA. I think it's fascinating. Henry Louis Gates

We can look at the characteristics of  ancestors to predict characteristics of offspring.  The pedigree tool is a useful way to predict passing of characteristics in live stock and in people.  This is useful to geneticists in predicting the likelyhood of genetic disease being passed to one's children.

Introduction to Evolution

Evolution is a tinkerer. Francois Jacob

Evolution is the change of habitable traits to a population across generations.   We will explore this concept, and try to expain how it works.  This is a complicated topic that has a specialized vocabulary.  We'll have a lot of work to do here.

Evolution by Natural Selection

Natural Selection, as it has operated in Human history, favors not only the clever, but the murderous. Barbara Ehenreich

Organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution.  It is a simple concept, but notalways easy to understand.  We'll be doing our best to understand the implications of this idea.

Evolution by Sexual Selection

That's a Fine Pair of Genes You're Wearing. Anon.

The natural selection arising through preference by one sex for certain characteristics (like peacocks with bigger tail) in individuals of the other sex (by peahens).

Mechanisms of Evolution

We are like the mechanism of a watch: each part is essential. Nathan Meyer Rothschild

So, we've seen how evolution can happen - but how do traits become stabilized in a population?  That's what we'll be looking at here.

Photosynthesis

...I observed that plants not only have a faculty to correct bad air in six to ten days, by growing in it...but that they perform this important office in a complete manner in a few hours; that this wonderful operation is by no means owing to the vegetation of the plant, but to the influence of light of the sun upon the plant.  Jan Ingenhousz

All life on earth is dependant on the sun as a source of energy.  Plants capture the energy in sunlight and convert it into chemical energy that organisms can use for energy.  This allows all life on earth to be interconnected in a process that recycles everything in a perfect balance.