Unit 4 Study Guide: DNA, Biotechnology, Evolution, and Taxonomy

These flashcards cover key concepts from DNA structure, replication, and associated experiments, as well as RNA and protein synthesis.

What did Griffith's Experiment (1928) demonstrate?

It discovered transformation, showing harmless bacteria became harmful when exposed to heat-killed virulent bacteria.

Who discovered the pairing of nitrogen bases and what is the pairing rule?

Erwin Chargaff discovered that Adenine pairs with Thymine (A=T) and Cytosine pairs with Guanine (C=G).

What was the conclusion of the Hershey-Chase Experiment (1952)?

It showed that DNA, not protein, is the hereditary material.

How did Rosalind Franklin contribute to the understanding of DNA?

She used X-ray diffraction to reveal DNA's helical shape, assisting Watson and Crick in constructing the double-helix model.

What is the structure of DNA?

DNA is a double helix made of nucleotides (sugar, phosphate, base) with a sugar-phosphate backbone and base pairs as rungs.

Describe the semi-conservative process of DNA replication.

Each new strand of DNA consists of one original strand and one newly synthesized strand.

What distinguishes RNA from DNA?

RNA is single-stranded and contains ribose sugar and uracil (U) instead of thymine; DNA has deoxyribose and thymine.

What are the three types of RNA and their functions?

mRNA: carries code from DNA, rRNA: forms part of ribosome, tRNA: carries amino acids to ribosome.

What are the two processes of protein synthesis?

Transcription (DNA to mRNA in the nucleus) and Translation (mRNA to protein in the ribosome).

What is a gene mutation?

A change in the DNA sequence that can be caused by mutagens like radiation, chemicals, or viruses.

Define an amino acid and a polypeptide.

An amino acid is a building block of protein, while a polypeptide is a chain of amino acids.

How can DNA sequences be converted to amino acids?

By converting DNA to mRNA, then to tRNA, and finally to amino acids using a codon chart.