Modern Biology Test Review PDF

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Study Guide for test #2 ...

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Modern Biology Test Review 

DNA is made of building blocks called nucleotides. The rungs of the DNA “ladder” consist of complementary base pairs (A with T and C with G). Hydrogen bonds hold the two strands together.

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The two chains of the DNA double helix are antiparallel with the 3’ end of one strand with the 5’ end of the complementary strand A nucleotide is composed of all of the following EXCEPT a A. Sugar B. Nitrogen-containing group C. Sulfur- containing group D. Phosphorus-containing group A gene is a segment of DNA that encodes a A. Protein or a functional RNA molecule B. Lipid or a protein C. Carbohydrate or a lipid D. Functional RNA molecule or a carbohydrate Transcription copies a _________ to a complementary_________ molecule. A. Chromosome; DNA B. Genome; RNA C. Gene; RNA D. DNA sequence; ribosome Choose the DNA sequence from which this mRNA sequence was transcribed: 5’AUACGAUUA-3’ A. 3’-TATGCTAAT-5’ B. 3’ -UTUGCUTTU-5’ C. 3’-UAUCGUAAU-5’ D. 3’-CTCAGCTTC-5’ How many different three-codon sequences encode the amino acid sequence Phe-ValAla?

1.

2.

3.

4.

5.

A. 1 B. 4 C. 8 D. 32 6. What is the job of the tRNA during translation? A. It carries amino acids to the mRNA B. It triggers the formation of a covalent bond between amino acids C. It binds to the small ribosomal subunit D. It triggers the termination of the protein Write it Out 1. Explain Chargaff’s observation that a DNA molecule contains equal amounts of A and T and equal amounts of G and C 2. Write the complementary DNA sequence of each of the following base sequences: a. A G G C A T A C C T G A G T C b. G T T T A A T G C C C T A C A c. A A C A C T A C C G A T T C A 3. Put the following in order from smallest to largest: Nucleotide, genome, nitrogenous base, gene, nucleus, cell, codon, chromosome 4. What is the function of DNA? 5. List the three major types of RNA and their functions 6. Some people compare DNA to a blueprint stored in the office of a construction company. Explain how this analogy would extend to transcription and translation. 7. List the sequences of the mRNA molecules transcribed from the following template DNA sequences: a. T G A A C T A C G G T A C C A T A C b. G C A G T A A A G A T C 8. How many codons are in each of the mRNA molecules that you wrote for question 7? 9. MET-ALA-PRO-LEU-PHE-SER-TYR-GLN-RF Intron [UCCGACU] at the 5th nucleotide in Pre mRNA

Post mRNA: Pre-mRNA: DNA Template: DNA Compliment:

10. During translation the mRNA sequence GCACUA would code for which amino acid sequence? 11. DNA Template: ACTGCCACTTTTGGAC DNA Compliment: Pre-mRNA: Post-mRNA: 12.MET-LEU-TRY-VAL-ALA-SER-PRO-RF Intron [UCAGCCU] at the 5th Nucleotide in Pre-mRNA Post mRNA: Pre-mRNA: DNA Template: DNA Compliment: 13.DNA Compliment: TACGGACTACCGGACCT DNA Template: Pre-mRNA: Post-mRNA:  There are 2 types of cell division o Mitosis makes identical cell copies o Meiosis makes gametes (egg and sperm) which are not identical

 Before cells divide they must replicate their DNA

 Mitosis: Process by which 1 parent cell gives a rise to 2 identical daughter cells/ cell division  Cells that undergo mitosis go through a repeating pattern: Cell Cycle

 The cell Cycle is regulated by several checkpoints o Checkpoints are enzymes (proteins) that move through the cell to make sure it is healthy before it divides

 What happens if acell fails a checkpoint?  – Apoptosis = programmed cell death (cell suicide): it seems extreme that a cell would kill itself, but it is very usefulfor 3 big reasons 1. destroys cells that are not in good condition (infected with a virus, has mutations, etc.) 2. removes old cells so that new ones can take their place o red blood cells only live ~120 days before undergoing apoptosis being replaced o skin cells only live ~20 days o colon cells only live for ~4 days 1. A DNA molecule is placed in a test tube containing fluorescently tagged nucleotides. DNA replication is induced. After replication, a. Only one DNA molecule would have two fluorescent strands b. Both strands of each DNA molecule would be half-fluorescent c. Each DNA molecule would have one fluorescent strand d. Both DNA molecules would be completely fluorescent 2. Explain how cell division and cell death work together to form a functional multicellular organism

3. If a cell somehow skipped G1 of interphase during multiple cell cycles, how would the daughter cells change? 4. Why do chemotherapy and radiation sometimes kill hair follicle cells, while leaving many other body cells unaffected?...