1 DNA OBJECTIVES: 12.1 Summarize the relationship between genes and DNA. Describe the overall structure of the DNA molecule.

2 Fredrick ________ was trying to figure out how bacteria made people sick. Griffith had isolate two different strains of _________. He cultured both strains and found that the disease causing one grew into ______ colonies,whereas the harmless strain produce colonies that _____ edges. The difference made the two strain easy to distinguish.

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5 He injected the mice with the _____________ strain, the mice developed pneumonia and ____. When mice were injected with the ________ strain, they didn’t get sick at all. He thought that the disease causing bacteria might produce a ______. He the took the disease-causing bacteria and ______ them, to _____ it, and injected them into mice. The mice ___, proving it was not producing poison.

6 Griffith then mixed the heat-killed bacteria, disease causing bacteria with ____, harmless ones and injected the mixture into mice. The mice developed ___________ and some died. The disease-causing bacteria ______ their ability to cause pneumonia to the harmless bacteria. ______________ is the process in which one strain of bacteria is changed by a _____ or _____ from another strain of bacteria.

7 _____ and other scientist discovered that the ______ ____ DNA stores and transmits the genetic information from on generation to the next.

8 ______ and ______ studied viruses that infects bacteria (____________). Bacteriophages are made of ___ or ___ core and a _______ coat. When the _____ enters a bacterium, the virus attaches to the _______ of the cell and injects its _______ information into it.

9 The _____ genes act to produce many new bacteriophages, and they gradually destroy the _________. When the cell splits open, hundreds of new _________ burst out. Hersey and Chase wanted to find out which part of the virus, the _______ coat or the ___ core, entered the cell. They grew viruses in culture that had a radioisotope of __________-32 and ______-35.

10 The protein coat contained almost no phosphorus and the DNA contains no sulfur. These were used as _______. If sulfur-35 was found in the _______, it would mean that the viruses’ _______ coat was injected into the bacteria. If phosphorus-32 was found in the bacteria, then the ___ had been injected. Hersey and Chase concluded that the _______ material of the bacteriophage was DNA not protein.

11 DNA is made up of units called _____________. A nucleotide is made up of three basic components: 1.A 5-carbon sugar (__________) 2.A __________ group 3.A nitrogenous base (_______, _______: purines) (_______, ________: pyrimidines) Purines have a ___ ring structure. Pyrimidines have only ___ ring.

12 _________ rules say that in any sample of DNA that the percentage of guanine and cytosine are almost equal and the percentage of thymine and adenine. This holds true of any organism’s DNA

13 ______ and _______ model of DNA was a _____ _____, in which two strands were wound around each other. Base pairing says that [A] = [T] and that [C] =[G].

14 CHROMOSOMES AND DNA REPLICATION OBJECTIVES: 12.2 Summarize the events of DNA replication. Relate the DNA molecule to chromosome structure.

15 __________ have a single circular DNA molecule that has nearly all the cell’s genetic material. The DNA molecule of ______ has 4,539,221 base pairs and is roughly 1.6 mm in length. For the DNA of a _________ to fit inside of it, it must be fold to only one-thousandth of its length. _________ has as much a 1000 times the amount of DNA as ___________. DNA of eukaryotes is located in the ______ in the form of a number of chromosomes.

16 The human cell typical holds more than one ____ of DNA. _________ is made up of DNA that tightly coiled around a proteins called __________. DNA and histones form a _________ structure called a _________, which pack together to form a system of loops and coils.

17 Because the rules of base pairing applies to DNA, each strand of DNA can be used to ___________ the other half. Because they can do this they are said to be _______________. ________ replication begins at one point and proceeds often in both directions, until the entire _____________ is replicated.

18 In larger eukaryotic chromosomes, DNA __________ occurs at hundreds of places. The site where separation and replication occurs are called replication ____.

19 During DNA replication, the molecule separates into ___ strands, then produces two new _____________ strands following the rules of _____ pairing. Each strand of the double _____ of DNA serves as a template, or model for the new strand. Replication is caused by _______ that “______” the DNA.

20 Enzymes are highly _______, and are usually name for the reaction they ________. DNA _________ joins individual nucleotides to produce a DNA molecule, it also ______ reads the new DNA strand. This helps to insure that each molecule is a _____ copy of the original.

21 RNA AND PROTEIN SYNTHESIS OBJECTIVES: 12.3 Tell how RNA differs from DNA. Name the three main types of RNA. Describe transcription and the editing of RNA. Identify the genetic code. Summarize translation. Explain the relationship between genes and proteins.

22 ______ are coded DNA instructions that control the production of ________ within the cell. The first step in decoding these genetic messages is to copy part of the _________ sequence from ___ to _____. There are _ main differences between DNA and RNA. 1.RNA contains _______ 2.Generally a ______ strand 3.RNA has _______ instead of ________.

23 RNA can be thought of as the __________ copy of a segment of DNA. In most cells the function of RNA is protein _________. The assembly of ______ acids into proteins is controlled by RNA. There are three types of RNA: 1.__________ RNA 2.__________ RNA 3.__________ RNA

24 The RNA molecule that carry copies of the instructions to make protein is _____. Proteins are assemble on _________, which are made of several dozen proteins, as well as a form of RNA called _____. During the construction of proteins _____ transfers each amino acid to the ________ as coded by _____. _________ is the copying of a part of a nucleotide sequence of DNA into a ___________ sequence in RNA

25 During transcription, RNA __________ binds to DNA and ________ the DNA strands. RNA polymerase then uses on strand of DNA as a ________ from which nucleotides are assembled into a strand of RNA. RNA polymerase only bind to specific sites called “________” (these have a specific base sequence). Eukayotes have ______ in their DNA, which do ____ code for protein. DNA sequences that code for proteins are called ______.

26 Both _______ and _____ are copied from DNA, but the introns are cut out of the RNA molecule. The exons are then spliced back together. Proteins are formed by long chains of amino acids called “____________”. The __________ of proteins are determined by the _____ in which different amino acids are joined together. A _____ consist of __ consecutive nucleotides that specify a single amino acid that is added to the polypeptide.

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29 The decoding of an _____ message into a polypeptide chain (_______) is known as translation. During ________, the cell uses information from messenger RNA to produce protein. 1.mRNA is __________ from DNA. 2.mRNA attaches to a ________. 3.As it moves through the ribosome, the proper amino acid is brought by _____ (each molecule carries a ________ amino acid).

30 4. Each tRNA has an ________, which is three unpaired bases. 5. Ribosomes form a _______ bond between the first and second amino acid. 6. _____ is then released. 7. The polypeptide chain grows till it reaches a ____ ____. The chain is then released.

31 MUTATIONS OBJECTIVE: Contrast gene mutations and chromosomal mutations.

32 ________ are a change in genetic material. Gene mutations involving changes in one or a few nucleotides are known as _____ ______. They occur at a single point where one base is changed (includes insertions and deletions). Tay Sac ___ _____ starts about 6 months old and usually results in death at about __ years of age.

33 Original: The fat cat ate the wee rat. Point mutation: The fat hat ate the wee rat.

34 If a nucleotide is ______ or _______ the bases are still read in groups of three (_____), but now those groupings are shifted for every codon that follows, this is called __________ mutation. Original: The fat cat ate the wee rat. Deletion: Tef atc ata tet her at.

35 Hypopigmentation and hyperpigmentation Familial cylindromatosis

36 _____________ mutations involve changes in the number of chromosomes. 1._______ – the loss of all or part of a chromosome. 2.__________ – produces extra copies of parts of chromosomes. 3._______ – reverses the direction of chromosomes. 4.__________ – when part of one chromosome breaks off and attaches to another.

37 Most mutations are ______, with little or no effect. Some mutations changes the ___________ of a protein that disrupts normal biological activities. When a complete set of chromosomes fail to separate during _______, the _______ that result may produce _____ (3N) or _______ (4N) organisms. When a organism has an extra set of chromosomes it is called ___________.

38 GENE REGULATION OBJECTIVES: 12.5 Describe a typical gene. Describe how the lac genes are turned off and on. Explain how most eukaryotic genes are controlled. Relate gene regulation to development.

39 Genes turn off and on by a group of genes that operate together called an _______. For bacteria to use ______ as a food, they need a lac operon. The lac genes are turned off by ______ and turned on by the presence of lactose. Most eukaryotic genes are controlled individually and have regulatory sequences that are much more complex than those of the lac operon.

40 The “_____ box” seems to help position RNA __________ by marking a point just before the point at which _________ begins. ___________ is when cells become specialized in structure and function. ______ genes control the differentiation of cells and tissues in the embryo.

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