The enzyme that is responsible for replicating molecules of DNA by attaching complementary bases in the correct sequence is called ____________________ ____________________. 27. Enzymes called ____________________ are responsible for unwinding the DNA double helix by breaking the hydrogen bonds that hold the complementary strands together. 28. Errors in nucleotide sequences are called ____________________.
The DNA components shown in the Gizmo are phosphate molecules and deoxyribose sugars 2. A nucleoside has two parts: a pentagonal sugar (deoxyribose) and a nitrogenous base (in color). When a nucleoside is joined to a phosphate, it is called a nucleotide. How many different nitrogenous bases do you see? 4 Note: The names of these nitrogenous bases are adenine (red), cytosine (yellow), guanine (blue), and thymine (green).
[pic] For each of the cells labelled B and C, identify the type of cell division, which has occurred to produce the cell. In each case give a reason for your answer. (2) 4. Read through the following passage on the cell cycle and mitosis, then write on the dotted lines the most appropriate word or words to complete the passage. (6) In the cell cycle, replication of DNA takes place during .......................a.............................. At the beginning of prophase the chromosomes become visible and can be seen to consist of two ..................b...........................joined at the ......................c...............................
To confirm this idea, Marshall Nirenberg used a synthetic RNA containing only one kind of base. What question was his experiment attempting to answer? 8. Briefly describe Seymour Benzer’s experiment that answered the question: “Do mutations in the DNA sequence of a gene correlate with protein changes?” 9. Marshall Nirenberg and Heinrich Matthaei used mRNA made up of repeating uracil nucleotides in a cell free extract.
A ribosome can also be known as the chemical factory. Messenger ribonucleic acid (mRNA) has the job of making copies of parts of the DNA as required by the body and taking it through the chemical factory. So in relation to the topic of this essay, a messenger mRNA comes along and takes a copy of a digestive enzyme from the DNA and squeezes through the pores with it into the cytoplasm . In this environment it heads towards the ribosomes and passes through the ribosome where protein synthesis and translation occurs. The protein then passes to the Golgi apparatus where it is processed and packaged or more simply modified and labelled for its digestive function then released in vesicles to go and perform its specific function.
3. Describe each stage of the flow of information starting with DNA and ending with a trait. Information will start with the DNA traveling to the RNA and into the protein. This information flow will also be followed through the cell as it travels from the DNA in the nucleus, and the Cytoplasm, then to the Ribosomes and the Endoplasmic Reticulum, and finally to the Golgi apparatus, this system packages the final products for export outside the cell (Science Daily, 2013). Reference UIC.edu.
Plasmid has at least one DNA sequence that can act as an origin of replication. Plasmid almost always carry one or more gene which is responsible for a useful characteristic displayed by bacteria .e.g. Antibiotic resistance gene, therefore it is used as selectable marker. All plasmid possess atleast one DNA sequence that can act as an “origin of replication”, so they are able to multiply with the cell quite independently of the main bacterial chromosome. The smaller plasmids make use of the host cell’s own DNA replicative enzymes in order to make copies of themselves, whereas some of the larger ones carry genes that code for special enzymes that are specific for plasmid replication.