Genetica

WELCOME to genetics! This is a course that some of you have been anticipating, and many have been fearing. It is both a body of knowledge itself, and a way of studying other subjects. As such, it has a GREAT deal of application to other subjects such as evolution, ecology, cell biology, developmental biology, and cancer.

Today, we’re going to cover the main parts of the course, then get right into an overview of genetics.

I. What is genetics?

Organisms can be described in many ways: By their shapes and parts, by their activities; by their reproduction. For all these things, there is a need for information: Information that told you, when you were embryo how to grow and change, so that you became a baby, then a child, then an adult. Information that resulted in some cells becoming muscle, some skin, some bone cells. Information that allows you to respond to your environment; and information that allows you to reproduce. That information has to: 1) exist- it’s origins are outside the scope of this course, for the most part;

2) be expressed properly: The right information, expressed at the right time and place.

3) be stored properly: We take pains to keep our information from being damaged, although it does happen.

4) It must be Transmitted in order to make new cells and organisms.

This is very much like a CD or DVD; both store information; and neither does you any good unless you can express it properly- for that you need a CD or DVD player. And the information in a CD can be reproduced- copied.

The study of biological information, its form, how it is expressed, stored, repaired, and transmitted, is the science of genetics. It’s usually called the study of heredity, but when you think about it, heredity has to do with information.

While we will spend much time on the key information molecule, DNA, we’ll also talk about cases in which the information required for formation of an organism is not actually found in the DNA- we’ll discuss that later in the semester.

II. Four ways we study genetics: We can usually study genetics in four different ways; however, these ways often overlap!

Transmission Genetics: How are traits transmitted from one generation to another?

(AKA MENDELIAN Genetics); describing an allele as dominant or recessive, a gene as sex-linked, would be describing how it is transmitted.

Molecular Genetics: What are genes made up of?

How are they duplicated?

How is the information in the genes expressed?

How are genes turned on and off?

Where are genes located?

Population Genetics: How do genes vary in a population? What causes this variation within populations? How are populations affected by their genes, and vice versa?

Cytogenetics: This area has to do with the relationship between the chromosome and traits that are exhibited.

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