DO NOW What is in a vaccine that makes it effective? What is an allergic reaction? What are the molecules that trigger immune responses? What happens to an onion cell in salt water? What is the function of a gene? Where does protein synthesis occur? If the amino acid sequence is changed, how will it affect the final protein product? Cheerios claims that eating 1 bowl of cheerios a day can help to reduce cholesterol. The whole grains have been said to lower LDL counts in patients with high cholesterol. Design a controlled experiment to test of the effects of whole grains on cholesterol levels. Hypothesis Independent variable Experimental group Data to be collected Data to support the claim

11 days til REGENTS! Regents Review TODAY (upstairs) Tutoring?

Genetic Engineering and Evolution 11 class days until the REGENTS

Gene A segment of DNA that codes for a protein DNA  mRNA  amino acid  protein

Selective Breeding- Controlled reproduction Selective Breeding- Controlled reproduction. Choosing DESIRABLE TRAITS to reproduce. Cross breeding corn to get desired traits such as size, sweetness, health Cross breeding wolves to get all modern day dog breeds Cross breeding strongest cows to make a “SUPER COW”

Selective breeding has happened for thousands of years!!!!!

MODERN SCIENCE RECENTLY (Last 25 years)… Scientists manipulate, or directly change the DNA of organisms to make new characteristics This is called GENETIC ENGINEERING

Scientists use ENZYMES to the cut a gene out of one organism, and insert the gene into another organism.

Scientists use ENZYMES to the cut a gene out of one organism, and insert the gene into another organism. DNA is a universal genetic code, so the new organism will express the gene to make the desired protein trait.

The human gene for insulin was cut from a human using an enzyme. The human gene for insulin was inserted into a bacteria using an enzyme The bacteria express the human gene and produce insulin. The insulin is collected and given to patients with diabetes.

Benefits of Genetic Engineering? Create new medicine Create better crops LOWER COSTS of medicine / food

ANY change in the DNA- whether by mutation or by genetic engineering will be passed on to every cell that develops from that cell. Mutated OR genetically engineered cell will pass on the changed DNA through mitosis

Mutations are completely random events Radiation, UV light, and toxins can increase your chances of a mutation.

Evolution A mutation in a body cell will only be passed on to body cells. A mutation in the gametes can be passed on to offspring.

Evolution Mutations and genetic recombination during sexual reproduction lead to new gene combinations and new traits. Genetic recombination occurs during meiosis and fertilization

Some characteristics give organisms an advantage over other organisms. Some traits help organisms survive and compete for resources. An adaptation is any trait/characteristics that helps you survive in a particular environment.

The organisms that are best adapted for their environment will naturally survive and reproduce more. Their genes and traits will be passed on to their offspring. This is natural selection for the most fit organisms.

Over time, the population of better adapted organisms will increase. Less fit species will decrease over time, because they cannot compete.