TAKS review DNA TAKS Review Obj 2 TEK

TAKS review: DNA

TAKS Review Obj. 2 TEK 6 (A) describe components of deoxyribonucleic acid (DNA), and illustrate how information for specifying the traits of an organism is carried in the DNA; (B) explain replication, transcription, and translation using models of DNA and ribonucleic acid (RNA); (C) identify and illustrate how changes in DNA cause mutations and evaluate the significance of these changes; (D) compare genetic variations observed in plants and animals;

TEK 6(A) 1. DNA is made up of thousands of units called There are 4 kinds of nucleotides. What are the nitrogen bases in DNA: three parts of the A, G, C, & T nucleotide? Adenine Guanine Cytosine Thymine Sugar, phosphate group, and nitrogen base 2. Which of these parts of the DNA stores genetic information? The sequence (order) of nitrogen bases. Phosphate group Deoxyribose

EXAMPLE A G T T C G G A might give you blue eyes, T G T C T A A G might give you brown eyes. The order of the nitrogen bases dictates the characteristics you have. The order dictates which proteins are made in your cells, and those proteins give your traits.

TEK 6(B) 3. Nitrogen bases in DNA come in pairs. T C and A bonds to ______ G bonds to ______ 4. If one side of the DNA is CAT TAC, then what would the complementary side of the DNA be? CAT TAC G TA A T G

An old TAKS question: n n n Sickle-cell anemia is a disorder resulting from a mutation that leads to the production of an abnormal protein. Which component of the DNA molecule provides instructions for the production of the protein? A The phosphate groups B The sugar molecules C The sequence of nitrogen bases D The bonds that hold the sugars to the bases

And another… In all plant and animal cells, the nucleus contains long molecules of DNA. Which of the following best describes the function of DNA? F DNA provides the shape and structure of the nucleus. G DNA packages materials for transport through the nucleus. H DNA carries materials into and out of the nucleus. J DNA contains the blueprint for producing the whole organism.

And another… If the template of a strand of DNA is 5' AGATGCATC 3', the complementary strand will be — F 3' TCTACGTAG 5‘ G 5' CTACGTAGA 3‘ H 3' AGATGCATC 5‘ J 5' AGACGTCTA 3'

And even one more: Erwin Chargaff studied the DNA of organisms within a single species. Chargaff discovered that the amount of adenine is about equal to the amount of thymine. Which of these explains why the ratio of adenine to thymine is nearly 1: 1? A Adenine and thymine pair with each other. B Adenine binds with phosphates, while thymine binds with nitrates. C Adenine and thymine are identical in chemical composition. D Adenine bases contain a form of thymine.

One more… The sequence of amino acids coded by a strand of DNA directs the cell to make specific A. B. C. D. Carbohydrates Lipids Proteins Vitamins

DNA replication

TEK 6(B) 5. What happens just before a cell divides? DNA replication occurs so that each new cell can have an exact copy of DNA. (Note: Body cells divide in mitosis to create two identical cells that have identical DNA and the same number of chromosomes. )

Think of the replicator on Star Trek: replication means copying.

TAKS question… If a cat has 38 chromosomes in each of its body cells, how many chromosomes will be in each daughter cell after mitosis? F 11 G 19 H 38 J 76

Making Proteins Review: In what part of the cell are proteins made? Where are the instructions for making those proteins? There are two steps in making proteins: transcription and translation

DNA transcription

DNA transcription DNA contains the instructions to make proteins. Unfortunately, the instructions are in another language, and the workers that will actually make the proteins don’t understand it. That’s where m. RNA comes in – it will provide the directions in a language the workers can understand.

DNA transcription In transcription, the DNA is unzipped, and m. RNA is transcribed. The instructions for making proteins are written into the m. RNA. Think of a prescription: the doctor’s orders are written down. “script” means something written down.

TEK 6(B) 6. Which nitrogen bases in found in RNA but not in DNA? Uracil –U (A bonds to U in RNA) 7. What would the m. RNA codon be that would be created from the DNA sequence: CAT TAC? DNA- CAT TAC m. RNA- G U A A U G

TEK 6(B) 8. What is the process of copying the genetic information in DNA to m. RNA called? Transcription nucleus Nucleus What: Copies DNA to make m. RNA Where: In the nucleus Why: to carry instructions out of nucleus m. RNA DNA RNA Polymerase

DNA translation After the m. RNA brings the instructions from the nucleus to the site of protein production, the protein is assembled during translation.

TEK 6(B) 9. m. RNA contains information on what order to put amino acids together to form a Protein _______ chain during the process of translation. 10. The codon AUG codes for which amino acid? AUG= methionine

Let’s practice making a protein… http: //learn. genetics. utah. edu/content/begin/dna/t ranscribe/

Practice question: A cell with numerous ribosomes is probably specialized for— A. B. C. D. enzyme storage energy production protein synthesis cell division

TEK 6(C) 11. What is a mutation? is a change in genetic material (Change in DNA leads to changes in protein chain. ) DNAMutation in one DNA base m. RNAAmino Acid chain (Protein)- Causes changes in one m. RNA base New codon codes for a different amino acid

Sample TAKS question: A mutation is defined as: A. a change in an organism's DNA B. the growth of an abnormal cell structure C. the changing of a cell from one type to another D. a way of changing m. RNA to proteins

Question: The molecule which acts as an intermediary between the DNA and the ribosomes is A. B. C. D. messenger RNA transfer RNA ribosomal RNA intermediate RNA

TAKS question: Mutations in DNA molecules can occur when — F. G. H. replication of DNA is exact a DNA enzyme attaches to an RNA codons are replaced by DNA nucleotides J. a change occurs in DNA nucleotide bases

Genetics Vocabulary Review TEK 6(D) Genotype: genetic make-up of an organism ex. Bb Phenotype: expression of the genes of an organism (ex. BLACK hair. ) Dominant: trait that is always expressed Recessive: trait that can be hidden in the presence of a dominant gene. Gene: segment of DNA that codes for a protein that controls a trait. Trait: inheritable characteristic