Features of Cells
All cells enclose themselves within this structure that controls nutrient and waste exchange.
What is the plasma membrane?
A gene corresponds to this molecular fragment that encodes one protein.
What is a DNA sequence or gene?
The three primary branches of the tree of life are Bacteria, Archaea, and this.
What are Eukaryotes?
A comparison of protein sequences helps identify these groups of related proteins.
What are protein families?
Eukaryotic chromosomes package DNA with these proteins for orderly organization.
What are histones?
This chemical molecule stores hereditary information in all living cells.
What is DNA?
This term describes the set of all genes in an organism.
What is the genome?
This process allows genes to move between organisms, common in single-celled species.
What is horizontal gene transfer?
This evolutionary mechanism creates new genes from preexisting ones.
What are gene duplications?
The chemical bonds that hold DNA strands together are this type of bond.
What are hydrogen bonds?
The process by which all cells create copies of their hereditary information.
What is DNA replication?
Transcription is the process of copying DNA into this molecule.
What is mRNA?
Most bacterial genomes contain this approximate range of genes.
What is 1,000–6,000 genes?
Protein families often contain members called these that perform somewhat different functions within one species.
What are paralogs?
DNA is made up of these subunits that form its long chains.
What are nucleotides?
Cells use proteins as this type of biological molecule to catalyze reactions.
What are enzymes?
Genetic information in all cells is transcribed into the same intermediary form—this type of molecule.
What is RNA?
These are genes related by duplication events within the same organism.
What are gene families?
The chapter references how natural selection shaped this fundamental coding system common to all life.
What is the genetic code?
This structural level refers to DNA wrapped around histone proteins forming "beads on a string."
What is nucleosome?
The intermediatory molecule that carries DNA information to the protein-making machinery.
What is RNA?
The genetic code has this remarkable property that minimizes the effect of mutations.
What is mutation resistance or error tolerance?
This term describes different genes descended from a common ancestor separated by a speciation event.
What are orthologs?
he book uses a uniform style for gene names that differ from species-specific conventions and are written this way.
What is italic with the first letter capitalized and the rest lowercase?
The genome of humans contains approximately this many base pairs.
What is 3 billion base pairs?