BIOL 1001 Chapter 22 (22.3)

What is a DNA double helix?

Two antiparallel strands of DNA twisted together.

What are antiparallel DNA strands?

The two DNA strands run in opposite directions.

What are DNA base-pairing rules?

A pairs with T, and G pairs C.

What is a nucleotide?

Building block of DNA.

What is the genome?

Entire complement of genetic material in an organism.

What is a chromosome?

DNA associated with proteins into a complex structure.

What are gametes? Gametes are ____?

Egg and sperm cells, gametes are haploid.

What process forms gametes?

Meiosis?

Fertilization restores what chromosome number?

Diploid (2n).

What is the central dogma of molecular biology?

DNA → RNA → Protein.

What is transcription?

DNA is copied into RNA.

What is translation?

mRNA is used to make a polypeptide/protein.

What processes occur in ALL organisms?

Transcription and translation.

Why are similarities in molecular processes important evidence for evolution?

They suggest all organisms evolved from a common ancestor.

What is Homology?

Similarity due to shared ancestry.

What is Analogy?

Similarity due to convergent evolution.

What’s the problem with using only morphology to determine relationships?

Convergent evolution can make unrelated species appear similar.

What is Molecular homology?

Similarities between organisms at the molecular level due to common ancestry.

What are Homologous genes?

Genes derived from the same ancestral gene.

What are Orthologs?

Homologous genes found in different species due to speciation.

What are Paralogs?

Homologous genes within the same species due to gene duplication.

Gene duplication can lead to?

Gene families.

What is Vertical evolution?

New species arise from pre-existing species through accumulated genetic changes.

What is Horizontal gene transfer?

Exchange of genetic material between organisms that are NOT direct descendants.

Horizontal gene transfer is especially common in?

Prokaryotes/bacteria.

3 methods of horizontal gene transfer?

Transformation, transduction, and conjugation.

What is Transformation?

Uptake of foreign DNA from the environment.

What is Transduction?

Transfer of genes between bacteria by bacteriophages (viruses).

What is Conjugation?

Transfer of genetic material between bacteria through direct contact.

What is Bacteriophage?

Virus that infects bacteria.

Why are bacteria considered “evolution in overdrive”?

They reproduce quickly and can rapidly gain beneficial traits like antibiotic resistance.

Example of rapid bacterial evolution?

MRSA resistance to antibiotics.

Natural selection does NOT create new traits; it?

selects for traits already present in the population.

Selective pressures determine?

Which traits are useful in an environment.

Evolution can occur at the genomic level through changes in?

Chromosome structure or chromosome number.

Orthologs occur in _____ species while paralogs occur in _____ species?

different; the same.

Difference between homology and analogy?

Homology = shared ancestry; analogy = convergent evolution.

Sugar glider and flying squirrel are examples of?

Sugar glider and flying squirrel are examples of.

Marsupial mole and mole are examples of?

Convergent evolution.

The universal nature of transcription and translation suggests?

These processes evolved early in the history of life.