1. DNA Structure and Replication
SC.912.L.16.9
Explain why the genetic code is universal.
Explain why there are similarities in the genetic code of different organisms.
SC.912.L.16.3
Describe the basic process of DNA replication.
Explain why DNA replication has a role in the transmission and conservation of the genetic material.
Demonstrate the process of DNA replication given a DNA strand.
SC.912.L.16.4
Analyze the causes of gene and chromosomal mutations to predict the possible effect in a DNA sequence.
Explain how mutations in a DNA sequence may or may not result in a phenotypic change.
Explain how mutations in gametes may result in phenotypic changes in offspring.

2. Why is the genetic code universal?
All organisms have DNA made of the same molecules.
DNA in every organism has the bases: A,T,C,G

3. Why are there similarities in the genetic code of similar organisms?
Most organisms share a common ancestry and the process of inheritance carries traits from generation to generation.

4. How does the process of DNA replication enable genetic information to be transmitted and used to build proteins?
DNA  RNA  Protein
DNA Replication= making an identical
copy of a DNA strand

5. DNA Replication
DNA replication begins with the unwinding of the DNA double helix by several enzymes.
The exposed strands are then used as a template, or model, to build the new strand according to base pairing rules (A to T, C to G).
At the end of the process, there are two, identical strands of DNA, each with part of the original strand and a newly created strand.

6. How can DNA mutate?
Mutation = a mistake or change in the DNA sequence.
Causes: mistake during replication,exposure to x-rays, ultraviolet light, radioactive substances or certain chemicals.

7. Why don't all mutations result in visible change?
Not all mutations are harmful, some may be beneficial, and may not be visible (silent mutation).
Silent mutations occur because the same amino acid is created despite the error.

8. DNA Replication
Key Vocabulary: DNA, protein synthesis, replication, RNA, transcription, translation, mRNA, tRNA, ribosome, amino acid, protein

10. 1. Which of the following statements describes processes that occur during DNA replication?
a DNA sequence is read by RNA polymerase, which produces another RNA strand complementary to the first strand.
Two free-floating single strands of DNA are joined by polymerase. The polymerase finds the point at which the two strands will match up into a double strand.
Messenger RNA are decoded by a ribosome to produce an amino acid chain. In the cell's cytoplasm, transfer RNA join the messenger RNA, forming a polypeptide.
A double-stranded DNA molecule is unwound into single strands. Polymerase matches the right nucleotides to the single strand so that each forms a double strand of DNA.

11. 2. The genetic code is nearly universal, meaning that almost all organisms use the same genetic code. Which statement does NOT help explain why the genetic code is nearly universal?
all organisms encode their genes using DNA or RNA
All organisms can grow, respond to stimuli, and reproduce
All organisms use the same codon for the same amino acid.
All organisms are genetically related to all other organisms.

12. 3. DNA mutations can be present in a gene for many reasons
3. DNA mutations can be present in a gene for many reasons. Which of the following does NOT describe a reason genetic mutations may exist in a gene?
When a cell dies, the DNA in the cell's nucleus can mutate.
Exposure to chemicals or radiation can cause mutation in DNA.
Mutations in DNA can be passed down from a parent to a child.
Polymerase can make a mistake in matching nucleotides during replication.

13. 4. Mutations in an organism's DNA may be either beneficial or harmful
4. Mutations in an organism's DNA may be either beneficial or harmful. Which of the following statements best describes the concept of DNA mutation?
DNA mutation is an alteration in DNA replication that always results in phenotypic change. Mutations are usually due to radiation or other environmental factors
DNA mutation is a change in the way that genes reproduce themselves, which may or may not affect phenotypic characteristics. Mutations are usually due to environmental factors or heredity.
DNA mutation is a change in the gene sequence, which sometimes results in phenotypic change. Mutations can be due to environmental factors, heredity, or a mistake in DNA replication
DNA mutation is an alteration in the nucleus of a cell that makes certain genes unable to be copied, and they result in phenotypic change. Mutations are usually due to viruses and environmental factors