1. Genetics

2. Pine seeds grow into pine trees Nile crocodiles raise baby Nile crocodiles

3. Why? In all living organisms, offspring resemble their parents because they inherit their parents’ genes

4. What is a gene?
A gene is a section of DNA that contains the instructions for making a protein. In eukaryotes, DNA is found in the nucleus and is packaged in chromosomes Human cell – 7 ft of DNA Histones (proteins) keep it from tangling

5. Structure of DNA Double helix
Backbone made of alternating molecules of deoxyribose sugar and phosphate
Held together by covalent bonds

6. Four different nitrogenous bases
adenine (A) pairs with thymine (T)
cytosine (C) pairs with guanine (G)
Bases are held together by hydrogen bond bonds

7. A single nitrogenous base bound to a single molecule of sugar and a single phosphate is called a nucleotide

8. DNA Replication DNA has to be copied before cell division
Process is called replication
DNA spiral “unzips”
Each strand serves as a template for building new partner

9. Free nucleotides bind to complementary nucleotides
Attached by enzymes called DNA polymerase
DNA molecules are identical to the original

10. How does DNA provide instructions for cells to build proteins?
Processes of transcription and translation
Key molecule – Ribonucleic acid (RNA)

11. RNA Single-stranded Sugar – ribose
Base is uracil (U) instead of thymine (T)

12. Transcription – DNA is used as a template for building a molecule of RNA
Translation – RNA molecule is used to assemble proteins

13. Recall that proteins provide structure function in cell signaling
protect organisms from disease
initiate chemical reactions (enzymes)