Life Science January 21

  We will finish the lab questions on January 23.  Also, bring colored pencils on Thursday.  It is a 20 point assignment pass\fail to come with colored pencils.

Objective:	Name: Date:
	Critical Question:

                                    Chapter  6.1 What Does DNA Look Like?

                             

                              (Pg. 144) DNA stands for deoxyribonucleic ________________.

                                   

                                    (Pg. 144) What is a nucleotide?

                                   

                                    (Pg. 144) What are the four bases?

(Pg. 144)  Look at Figure 1 at the bottom of the page.  Draw and label the four nucleotides of DNA.

(Pg. 145) After seeing Franklin’s X-ray images, Watson and Crick concluded that DNA must look like what?

(Pg. 146) The shape of DNA is known as a double _____________.

(Pg. 146) What are the two sides of the DNA ladder made of?

(Pg. 146) What are the rungs of the DNA ladder made of?

 

(Pg. 146) Adenine always pairs with _______________.  Guanine always pairs with _______________.

DNA Bead Model Lab

       

        Name: ______________________________ Date: ______ Class: _____

Directions:  Please follow the steps below in order to build your DNA molecule. After you have finished be sure to turn your paper over and answer the questions on the back of this paper.

Materials:

• 2 feet of pipe cleaners
• 8 beads of  4 colors (you will need to identify which nucleotide is which color)
• 20 round black beads
• 20 round gold beads

Steps to Complete:

1. Obtain all materials. Please be sure to use caution in gathering the materials to avoid spilling the beads and miscounting materials.
2. String the beads exactly as follows Black, White, then two complimentary nucleotides, White, Black..
3. Make sure that all of the beads stay right in the middle while you do the next step

Draw, color and label your model below:

Reflections Questions:

1. In the DNA model of a molecule you just built list the nucleotides with their colors and tell what their complimentary nucleotide is.

(Example, Adenine= red & Thymine= blue …)

                 

                 

2. In these DNA molecules the round gold and silver bead would represent what?

      a. bases          b. sugar           c. phosphate

      d. the rungs of the ladder      e. the sides or uprights of the ladder

      f. a, b and c are correct       g. b, c, and e are correct

      h. none of the above choices are correct.

3. Why do you think DNA exists in the double helix?

4. As you know in a DNA molecule, the bases, Adenine, Cytosine, Thymine and Guanine must pair up in a certain way. Please explain how below.

5. Please read pages 144 & 146 in your textbook and answer the following questions.

1. True or False: One side of the DNA is always the same as                                       the other?

2. What would a DNA molecule with the base sequence of AAATTGCTAGGTCA on one side look like on the other side?

3. Describe how DNA makes a copy of itself.