biology 12-17

What is the structure of DNA?

DNA is a double helix composed of two strands of nucleotides, with a sugar and phosphate backbone on the outside and nitrogen-containing bases paired in the middle.

What are the four nitrogen-containing bases in DNA?

Adenine (A), Cytosine (C), Guanine (G), and Thymine (T).

What is the process of DNA replication?

DNA replication involves the separation of DNA strands and the use of enzyme DNA polymerase to build new strands using old strands as templates.

What is transcription?

Transcription is the process of making RNA from a DNA template where RNA polymerase binds to DNA and adds nucleotides to build mRNA.

What is translation?

Translation is the process of making a protein from the codon sequence of mRNA, which occurs on ribosomes.

What is the start codon for translation?

AUG is the start codon for translation.

What are the stop codons for translation?

UAA, UAG, and UGA are stop codons for translation.

What is the difference between euchromatin and heterochromatin?

Euchromatin is loosely packed and available for transcription, while heterochromatin is tightly packed and considered inactive.

What is the role of transcription factors?

Transcription factors help RNA polymerase bind to DNA at the promoter region, facilitating transcription.

What is the role of transcription activators?

Transcription activators bind to enhancer regions on DNA and promote transcription.

What is gene expression regulation in eukaryotes?

Eukaryotes control gene expression through transcriptional, posttranscriptional, translational, and posttranslational mechanisms.

Define a clone.

A clone is an exact genetic copy of a gene, cell, or organism.

What is a restriction enzyme?

A restriction enzyme is produced by bacteria to cut foreign DNA at specific recognition sequences.

What is DNA fingerprinting?

DNA fingerprinting involves using PCR to amplify short tandem repeats (STRs) and comparing DNA from different sources.

Briefly describe the procedure for cloning a gene.

To clone a gene, cut both the chromosome and plasmid with the same restriction enzyme to create 'sticky ends,' then combine and insert into bacteria.

Define evolution.

Evolution is the change in the gene pool of populations over time.

What are the components of the Theory of Evolution Through Natural Selection?

Variation, competition for resources, differential reproductive success, and adaptation to changing conditions.

What are the different types of evidence for evolution?

Fossils, biogeographical evidence, anatomical evidence, biochemical evidence, and developmental biology.

Define population.

A population is a group of organisms of a single species living together in the same geographical area.

What is microevolution?

Microevolution is the change in allele frequencies in a population over time.

What is a gene pool?

A gene pool is the collection of all alleles for all genes in a population.

What are factors that can change allele frequencies in a population?

Mutation, immigration, a small gene pool, non-random mating, and natural selection.

What are the modes of natural selection?

Stabilizing, directional, and disruptive selection.

Define biological species.

A biological species is a group of organisms that can successfully interbreed.

What are reproductive isolation mechanisms?

Mechanisms that prevent interbreeding include habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, and gamete isolation.

What is speciation?

Speciation is the splitting of one species into two or more distinct species.

What is allopatric speciation?

Allopatric speciation occurs when populations are separated by a geographic barrier and evolve into separate species.

What is sympatric speciation?

Sympatric speciation occurs without geographic barriers, where populations evolve into separate species.

What is adaptive radiation?

Adaptive radiation is when one species gives rise to several new species when introduced to a new environment.