Question: What is a ribosome responsible for?
Answer: carrying out the chemical reactions to add new amino acids to a growing polypeptide chain

Question: How is the genetic code read?
Answer: via interactions with specialized RNA molecules called transfer RNA (tRNA)

Question: How many unpaired bases does each tRNA have?
Answer: three

Question: When are genes expressed?
Answer: only when the product is needed

Question: What are examples of a cell's external environment?
Answer: available nutrients, temperature and other stresses

Question: What are examples of a cell's internal environment?
Answer: cell division cycle, metabolism, infection status

Question: At which step can gene expression be regulated?
Answer: at any step

Question: What example of post-translational modification of a protein was first described in 1961?
Answer: The regulation of lactose metabolism genes in E. coli

Question: What is first copied into RNA as an intermediate in the manufacture of the final protein product?
Answer: A typical protein-coding gene

Question: In some cases, what are the actual functional products?
Answer: the RNA molecules

Question: What sort of synthesis occurs when the RNA molecules are the actual functional products?
Answer: the synthesis of ribosomal RNA and transfer RNA

Question: What sort of function are ribozymes capable of?
Answer: enzymatic function

Question: What are the DNA sequences from which ribozymes are transcribed known as?
Answer: non-coding RNA genes

Question: In what form do some viruses store their entire genome?
Answer: in the form of RNA

Question: Why do the cellular hosts of some viruses not have to wait for transcription to synthesize their proteins?
Answer: Because they use RNA to store genes

Question: What is one type of an RNA retrovirus?
Answer: HIV

Question: What sort of transcription does the genome of HIV require before its proteins can be synthesized?
Answer: reverse transcription

Question: Besides viruses, where has RNA-mediated epigenetic inheritance been observed?
Answer: in plants and very rarely in animals

Question: Where do organisms inherit their genes from?
Answer: from their parents

Question: How much of an asexual organism's genome is inherited from its parents?
Answer: a complete copy

Question: How many copies of each chromosome does a sexual organism have?
Answer: two copies of each chromosome

Question: How many sets of chromosomes does a sexual organism inherit from each parent?
Answer: one complete set from each parent

Question: Why do sexual organisms have two copies of each chromosome?
Answer: because they inherit one complete set from each parent

Question: According to Mendelian inheritance, what is part of the cause of variations in an organism's phenotype?
Answer: variations in its genotype

Question: What sort of characteristics are described by an organism's phenotype?
Answer: observable physical and behavioral characteristics

Question: What is a genotype?
Answer: particular set of genes

Question: What specifies a particular trait with a different sequence of alleles?
Answer: Each gene

Question: How many alleles do most eukaryotic organisms have for each trait?
Answer: two alleles for each trait

Question: Where can alleles be located in order to be either dominant or recessive?
Answer: at a locus

Question: When paired with any other allele for the same trait, what do dominant alleles give rise to?
Answer: their corresponding phenotypes

Question: When do recessive alleles give rise to their corresponding phenotype?
Answer: when paired with another copy of the same allele

Question: When do alleles assort independently?
Answer: in the production of gametes

Question: What are gametes?
Answer: germ cells

Question: What does the growth, development, and reproduction of organisms rely on?
Answer: cell division

Question: In cell division, what two cells are created? 
Answer: identical daughter cells

Question: What specialized enzyme is responsible DNA replication?
Answer: DNA polymerases

Question: Why does the sequence of one strand completely specify the sequence of its complement?
Answer: Because the DNA double helix is held together by base pairing

Question: What one word characterizes the process of DNA replication?
Answer: semiconservative

Question: What is one thing the cell must do once DNA replication is compete?
Answer: physically separate the two copies of the genome

Question: What is another thing the cell must do once DNA replication is complete?
Answer: divide into two distinct membrane-bound cells

Question: In binary fission, what shape is each genome?
Answer: circular

Question: In binary fission. when does each genome separate into daughter cells?
Answer: as the membrane invaginates to split the cytoplasm

Question: Compared to the rates of cell division in eukaryotes, with what speed does binary fission occur?
Answer: extremely fast

Question: The duplication and transmission of genetic material from one generation of cells to the next is the basis for what?
Answer: molecular inheritance

Question: Why do organisms inherit the characteristics of their parents?
Answer: cells of the offspring contain copies of the genes in their parents' cells

Question: In what type of organism will the offspring be a genetic copy or clone of the parent organism?
Answer: In asexually reproducing organisms

Question: In what type of organism will a specialized form of cell division called meiosis produce cells called gametes?
Answer: In sexually reproducing organisms

Question: What are the gametes produced by females called?
Answer: eggs or ova

Question: When can an event called genetic recombination or crossing-over sometimes occur?
Answer: During the process of meiotic cell division

Question: If the alleles on the chromatids are the same, what effect arises from genetic recombination? 
Answer: no effect

Question: If the alleles on the chromatids are different, what effect arises from genetic recombination? 
Answer: reassortment of otherwise linked alleles

Question: Each of a parent's two genes for each trait will sort independently into gametes according to what Mendelian principle?
Answer: independent assortment

Question: In genetic linkage, what sort of point is extremely unlikely to occur?
Answer: a crossover point

Question: What is it called when errors occur in DNA replication?
Answer: mutations

Question: What is the lowest error rate that occurs in eukaryotic cells?
Answer: 10−8 per nucleotide per replication

Question: What is the highest error rate that can occur for some RNA viruses?
Answer: 10−3

Question: What can small mutations be caused by?
Answer: DNA replication

Question: What can larger mutations be caused by?
Answer: errors in recombination

Question: What is it called when multiple different alleles for a gene are present in a species's population?
Answer: polymorphic

Question: What can some alleles give rise to?
Answer: different phenotypic traits

Question: What is a gene's most common allele known as?
Answer: the wild type

Question: What are rare alleles called?
Answer: mutants

Question: What is one cause of the genetic variation in relative frequencies of different alleles in a population?
Answer: genetic drift

Question: What are mutations that have no effect on an organism's phenotype called?
Answer: silent mutations

Question: What are mutations that do not change the amino acid sequence called?
Answer: synonymous mutations

Question: What are mutations that lead to amino acid sequence changes but leave the protein functioning similarly called?
Answer: conservative mutations

Question: What is a result of deleterious mutations?
Answer: Genetic disorders

Question: What does the directional selection of beneficial mutations lead to?
Answer: adaptive evolution

Question: What are genes with a most recent common ancestor called?
Answer: homologs