Question | Answer |
What does the science of genetics study? | The inheritance of living organisms |
What is the difference between genotype and phenotype? | Genotype- collection of specific genes that an organism contains. Phenotype- total expression of all the genes of an organism |
What is the relationship between the genome, the chromosomes, and the genes? | Genome is a total of all genetic infer contained by an organism. Chromosome is the structure that organizes the DNA. Gene is a subunit of a chromosome that contains specific trait info |
How many genes do the smallest viruses have? | 4-5 |
How many genes does a human cell have? | 20,000-25,000 |
How many total chromosomes do humans have? | 46 |
How many pair of chromosomes do humans have? | 23 |
Describe the bacterial chromosome: | Circular |
What is the function of a histone protein? | DNA wraps around it in eukaryotic chromosomes. |
What is the difference between a haploid and diploid cell? | Diploid cells have paired chromosomes and haploid cells only have one set |
Who are the two individuals who won the Nobel Prize for discovering the structure of the DNA molecule? | James Watson and Francis Clark |
Describe the structure of the DNA molecule: | Composed of two strands of nucleic acid that run antiparallel to each other in a double helix connected by hydrogen bonds |
What does it mean that the two strands in DNA run antiparallel? | One end is the 5' end and the other is the 3' end |
Which molecule is found at the 5' end of DNA? | Phosphate |
Which molecule is found at the 3' end of DNA? | -OH |
What are the individual subunits that make up the DNA polymer? | Nucleotides |
What are the three parts of every nucleotide? | Phosphate group, sugar, nitrogenous base |
Which of the three parts of a nucleotide forms the "rungs in the ladder" of DNA? | Nitrogenous base |
What are the four nitrogenous bases of DNA? | Adenine, guanine, cytosine, thymine |
Which two of the four nitrogenous bases of DNA are always paired together? | Guanine and cytosine |
How many hydrogen bonds do each pair of nitrogenous bases have? | Guanine and cytosine have three. Adenine and thymine have two |
What is synthesized in replication, transcription, and translation? | In replication, two new daughter strands of DNA are produced. Transcription is when a transcript of DNA is made by mRNA. Translation, the transcript is read. |
Why is DNA replication termed a "semi-conservative" process? | Each strand acts as a template for a new strand |
What is the advantage of a semi conservative process? | Allows for accurate replication |
How many different enzymes are involved in DNA replication? | 30 |
What is the advantage of having many A-T connections at the beginning of the replication process? | Less energy is required to separate them |
What action do helicases perform? | Unwind the double helix and separate the strands of DNA |
Can replication occur without an RNA primer? | No |
What is the major enzyme involved in DNA replication | Polymerase III |
Why does DNA replication have a leading strand and a lagging strand? | Because only a small section of the DNA opens at a time |
Which strand of DNA forms the Okazaki fragments? | The segmented strand |
Which type of RNA carries the code from the DNA in the nucleus to the ribosome in the cytoplasm? | Messenger RNA (mRNA) |
How many bases on the DNA does it take to code for one amino acid of a protein? | Three consecutive |
What is the set of three called that codes for one amino acid in the DNA? | Triplet |
How many possible triplets exist? | 43 or 64 |
What are the three major differences between DNA and RNA? | RNA is single-stranded, RNA replaces thymine with uracil, and the five carbon sugar in RNA is ribose instead of deoxyribose |
What is the major enzyme involved in RNA transcription? | RNA polymerase |
What do you call the three bases on the mRNA that correspond to the triplets on DNA? | Codons |
Which molecule brings the amino acids to the ribosomes? | Transfer RNA (tRNA) |
What do you call the bases on the tRNA that correspond to the codons on mRNA? | Anticodon |
What is found on each end of a tRNA molecule? | One end has an anticodon complimentary to the codon on mRNA, one end has the two amino acid that corresponds to that anticodon. |
How many tRNA molecules can attach to the ribosome at one time? | Two |
What is the name of the codon that translation always begin with? | The "start" codon |
What amino acid does the start codon code for? | Methionine |
What is the name of the codon that signals the protein is complete? | Termination codon, "stop" codon |
What is a mutation? | A change in a nucleotide sequence |
What are the two general causes of mutations? | Errors in replication and exposure to known mutagens |
What are the three types of point mutations? | Spontaneous, induced, substitution |
What are the three possible outcomes of substitution mutation? | The new codon can code for the same amino acid, it could code for a different amino acid, and it could code for a termination codon |
What would be the possible outcomes of an addition or deletion point mutation? | Will shift each codon by one base, changes the entire reading frame of the mRNA |
Would a protein be able to function after a frameshift mutation? | Nearly always, no |
What is synthesized by conjugation, transformation, and transduction? | Conjugation- genetic transfer between bacterial cells. Transformation- transfer of naked DNA into a recipient cell. Transduction- a segment of DNA is carried from one bacterial cell to another by a bacterial virus a bacteriophage |