biology 12-17

What is the structure of DNA?

DNA is a double-stranded polymer of nucleotides with a sugar and phosphate backbone on the outside and nitrogenous bases pointing towards each other in the middle.

What are the steps of DNA replication?

The two DNA strands separate, and DNA polymerase creates a new strand by complementarily pairing nucleotides one at a time with the old DNA strands.

What is transcription?

Transcription is the process of making RNA from a DNA template, initiated when RNA polymerase attaches to a promoter region.

What occurs during translation?

Translation is the process of forming a protein based on the codon sequence of mRNA, taking place in ribosomes with the help of tRNA.

What is the start codon for translation?

The start codon for translation is AUG, which codes for methionine.

What are the stop codons for translation?

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

What is the difference between heterochromatin and euchromatin?

Heterochromatin is tightly packed and inactive, whereas euchromatin is lightly packed and active.

What are transcription factors?

Transcription factors are proteins that help regulate transcription by assisting RNA polymerase in binding to the promoter.

What is the role of transcription activators?

Transcription activators bind to enhancer regions of DNA, which may be distant from the promoter, to enhance transcription.

What is a clone?

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

How does a restriction enzyme function?

Restriction enzymes, produced by bacteria, cut foreign DNA at specific recognition sequences.

What is DNA fingerprinting?

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

What are the steps in gene cloning?

Cut DNA and plasmid with a restriction enzyme, combine the DNA pieces with complementary ends, and place the recombinant plasmid 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?

1. Variation among organisms, 2) Competition for resources, 3) Differential reproductive success, 4) Adaptation to changing environments.

What types of evidence support evolution?

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

Define population.

A population is a group of organisms of the same species living together in a 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 total collection of alleles for all genes in a population.

What factors can change allele frequencies?

1. No mutation, 2) No migration, 3) Large gene pool, 4) Random mating, 5) No selection.

What are the modes of natural selection?

Stabilizing (favors average), directional (favors one extreme), and disruptive (favors both extremes).

Define biological species.

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

What are the reproductive isolation mechanisms?

1. Habitat isolation, 2) Temporal isolation, 3) Behavioral isolation, 4) Mechanical isolation, 5) Gamete isolation, 6) Zygote mortality, 7) Hybrid sterility, 8) F2 fitness.

Define speciation.

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

What is allopatric speciation?

Allopatric speciation occurs when populations are separated by a geographic barrier, leading to the evolution of separate species.

What is sympatric speciation?

Sympatric speciation occurs when populations evolve into separate species without geographical barriers.

What is adaptive radiation?

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