Name: ______

What do Genes Look Like? - notes (part 1)

Genes:
What are they?
Where are they? / I. ______- segments of DNA that carry hereditary instructions and are passed from parent to offspring; genes are located on ______


The structure of DNA / II. ______– Hereditary material that controls all the activities of a cell and provides the instructions for making proteins (proteins are the building blocks of the body and determine a person’s traits)
A. DNA is made of ______
B. Nucleotides have ______parts; 5-carbon ______, phosphate group, nitrogen base
1. Nucleotides are identical except for the nitrogen base
2. A nucleotide can contain 1 of 4 Nitrogenous Bases-
•______
•______
•______
•______

The amount of Adenine = Thymine, Cytosine = Guanine (Chargaff’s Rule)
Replication – how DNA makes a copy of itself
/
  1. The Double Helix- 1953, 2 American scientists, ______and Crick, discovered the structure of DNA using the X-rays made by Rosalind Franklin
A. 2 ______wound around each other like a twisted ladder
  1. Strands are held together by ______between nitrogenous bases.
  2. Adenine bonds to ______and Cytosine bonds to ______

Structure of DNA





  1. ______: Before a cell divides to produce new cells, DNA on every chromosome is copied so that each new cell has an identical set of chromosomes.

Self Check – part 1 / 1.The process of Making a copy of DNA during mitosis is called ______
2. How do bases pair up during replication?
3. Replicate the following strand of DNA : ACA GGC TAT AAT

4. Where is DNA stored in a eukaryotic cell? ______

What do Genes Look Like? - notes (part 2)

From DNA to Protein / I. How DNA works – DNA cannot leave the nucleus. A copy of the DNA code is made in the nucleus into RNA. RNA travels out of the nucleus to the ribosome where the code is read and the protein is assembled.
A. The nitrogen bases in every gene make a ______
B. Every three bases makes one ______
C. One codon is the code for one ______
D. Long chains of amino acids make______.
E. Proteins determine an organisms characteristics and traits
Translation: Using RNA and The Genetic Code to make Proteins / II. Making a Protein: Translation
DNA in the Nucleus: ATA GCT CCG TTA
Code is made into RNA: UAU CGA GGC AAU
***In RNA Thymine is replaced by ______******
Amino Acid Chain is made at the ribosome: Tyrosine: Arginine: Glycine: ______



Now using your Amino Acid Wheel, write the amino acid chain that each mRNA codes for. (Note: the code is based on mRNA codons not tRNA anticodons.)
Polypeptide #1 ______
Polypeptide #2 ______
Polypeptide #3______
Diabetes is a disease characterized by the inability to break down sugars. Often a person with diabetes has a defective DNA sequence that codes for the making of the insulin protein. Suppose a person has a mutation in their DNA and the first triplet for the insulin gene reads T A T. The normal gene reads T A G. What amino acid does the mutant DNA and the normal DNA code for and will the person with this mutation be diabetic?
Another mutation changes the insulin gene to read T C T (instead of the normal T A G). Will this person be diabetic? Explain.
Genetic Mutations /
  1. ______- changes in the DNA sequence that affect genetic information; Can affect all types of cells (not all are harmful).
  1. ______- affect sex cells – inherited by offspring (ex- Down Syndrome)
B. ______– affect other cells- not inherited by offspring (many cancers caused by somatic mutations)
Two Types of DNA mutations
/ IV. 2 types of mutations
A. ______(#1) - changes in a single gene. 2 types of gene mutations-
  1. ______- affect only one nucleotide
*Can be caused by substitutions
  1. ______- type of point mutation where nucleotide is inserted or deleted; affects every amino acid after that point.
*Can be cause by insertions or deletions
B.______(#2) - changes in whole chromosomes. 4 types of chromosomal mutations.
1. ______-- loss of all or part of chromosome
2. ______- segment of a chromosome is repeated
3. ______-chromosome becomes reversed
4. ______- part of a chromosome breaks off and attaches to a different chromosome
Effects of DNA mutations / V. What are the effects of______-?
  1. ______are altered.
  1. ______are unable to perform “normal” functions.
Sometimes ______are harmful, sometimes there is no affect, and sometimes mutations can be helpful. (Helpful when mutation produces a trait that aids in survival)
Changing DNA on purpose / VI. ______- when humans change the genes of an organism to achieve a desired result
  1. ______- allowing only the individuals with desired traits to reproduce. 2 types
  1. ______-crossbreeding dissimilar individuals: offspring will have the best of both
  2. Ex: donkey x horse = mule
  1. ______-breeding individuals with similar characteristics: maintain certain characteristics in offspring
  2. Ex: German Shepard x German Shepard = German Shepard
VII. ______– Desired genes are removed from one organism and added or recombined into another organism. This forms a transgenic organism with recombinant DNA
A. This is used to make proteins not normally made by the cell. Can be used to produce: Drugs like insulin, Vaccines, Plants resistant to Insects, Reduce pollution, Better crops/meat
DNA and Evolution /
  1. Evolution –natural process through which species ______over time
A. The ______“selects” the best traits – only those best suited will survive and pass on their traits to offspring.
B. ______– occurs because of genetic differences
caused by mutations in DNA