100 — Name the phase when the cell grows, DNA is replicated, and the nucleus is still visible.
100 — Interphase
100
100 — Name the four nitrogen bases of DNA.
100 — Adenine, Thymine, Cytosine, Guanine
100
100 — What does mRNA stand for?
100 — Messenger RNA
100
100 — Define the term "mutation" in one sentence.
100 — A mutation is a change in the DNA sequence.
200
200 — During which phase do chromosomes condense and spindle fibers begin to form?
200 — Prophase
200
200 — Which base pairs with Adenine in DNA? Which base pairs with Guanine?
200 — Adenine pairs with Thymine; Guanine pairs with Cytosine
200
200 — In RNA, which base replaces Thymine?
200 — Uracil
200
200 — Give one example of a harmful mutation and one example of a helpful mutation (short phrases).
200 — Harmful: mutation that causes a nonfunctional enzyme leading to disease; Helpful: mutation that improves camouflage or resistance to a local disease.
300
300 — What happens during metaphase? Give one specific event you would see in the cell.
300 — Chromosomes line up at the cell equator (metaphase plate); spindle fibers attach to centromeres.
300
300 — If one DNA strand reads G C T A A G, write the complementary strand.
300 — Complementary strand: C G A T T C
300
300 — Transcribe this DNA triplet into its mRNA codon: TAC.
300 — TAC → AUG
300
300 — Explain how a mutation in DNA could change a protein made by the cell.
300 — A mutation can change an mRNA codon, causing a different amino acid to be added to the protein, which can change the protein's shape and function.
400
400 — Describe cytokinesis in animal cells. What is physically happening to the cell?
400 — The cell membrane pinches in (cleavage furrow) and the cell splits into two daughter cells, each with its own nucleus.
400
400 — Explain why DNA replication is important before a cell divides.
400 — DNA replication makes an exact copy of the DNA so each new daughter cell will have the correct genetic information.
400
400 — Using the codon chart concept, translate the mRNA codon AUG into its amino acid name (start codon).
400 — AUG codes for Methionine (Met) and acts as the start codon.
400
400 — A single base change in a codon can cause a STOP codon to appear early. What effect would this have on the protein?
400 — An early STOP codon produces a shortened (truncated) protein that is usually nonfunctional.
500
500 — Put these phases in the correct order starting with Interphase: Telophase, Prophase, Metaphase, Cytokinesis, Anaphase.
500 — A student wrote that Guanine pairs with Thymine in DNA. Is this correct? If not, correct the statement and explain the correct pairing.
500 — Incorrect — Guanine pairs with Cytosine. Corrected statement: Guanine pairs with Cytosine in DNA; Adenine pairs with Thymine.
500
500 — Given the DNA sequence: TAC CGC TCC GCC GTC AAT ACC ACT, write the full mRNA sequence (codons) and the amino acid sequence (use common 3-letter amino acid abbreviations; indicate STOP if present).
mRNA: AUG GCG AGG CGG CAG UUA UGG UGA
Amino acids (3-letter): Met Ala Arg Arg Gln Leu Trp STOP (Verify with a codon chart; some codon synonyms may use different common abbreviations; teacher should confirm.)
500
500 — Provide a short scenario describing a mutation that could be helpful for an organism in its environment (2–3 sentences).
500 — Example: A mutation that changes fur color to better match a new environment could help an animal avoid predators and survive to reproduce.