DNA Replication
What is the name of the enzyme that unzips the DNA double helix during replication?
Helicase
Where in the eukaryotic cell does transcription occur?
Nucleus (in eukaryotes)
What is the name of the RNA that carries amino acids to the ribosome?
Transfer RNA (tRNA
In this first stage of mitosis, chromatin condenses into visible chromosomes and the nuclear envelope begins to break down.
What is prophase?
This process during prophase I involves homologous chromosomes exchanging segments of DNA, increasing genetic diversity.
What is crossing over?
What nitrogen base pairs with Adenine
What is Thymine
What sequence on DNA signals the start of transcription
What is a start codon?
What three-nucleotide unit on mRNA codes for a single amino acid?
Codon
During this stage, chromosomes line up along the cell’s equator, forming what’s known as the metaphase plate.
What is metaphase?
Unlike mitosis, this stage of meiosis I separates these paired structures, reducing the chromosome number by half.
What are homologous chromosomes?
Where does DNA replication occur.
Where is the nucleus?
Explain how transcription factors influence gene expression in eukaryotes.
Transcription factors bind promoters/enhancers to recruit or help RNA polymerase, activating or repressing transcription.
What forms chains to create a protein?
Amino acids
This phase is marked by sister chromatids being pulled apart toward opposite poles of the cell.
What is anaphase?
This term describes the random orientation of homologous chromosome pairs at the metaphase plate during meiosis I.
What is independent assortment?
If a DNA strand contains 20% of cytosine, how much Adenine is present?
What is 30%?
How are the base pairs in mRNA different from those in DNA?
A pairs with U, not T.
This cellular structure reads mRNA sequences in sets of three nucleotides called codons to build a protein.
What is a ribosome?
In this final stage of mitosis, two new nuclear envelopes form around the separated chromosomes.
What is telophase?
The failure of chromosomes to separate properly during meiosis, which can lead to conditions like Down syndrome, is called this.
What is nondisjunction?
Explain why replication is described as semi-conservative.
Semi-conservative: each daughter DNA molecule contains one original (parental) strand and one newly synthesized strand.
Why does the DNA not leave the nucleus?
To protect the important information contained in its code from damage.
These three specific mRNA sequences—UAA, UAG, and UGA—do not code for amino acids and instead signal the end of protein synthesis.
What are stop codons?
This process, which often overlaps with the end of mitosis, divides the cytoplasm into two daughter cells.
What is cytokinesis?
What is the end result of meiosis?
4 genetically unique daughter cells