Biology Test 2 2
Terms
undefined, object
copy deck
- the impact of a single gene on more than one characteristic
- pleiotropy
- a molecule carrying DNA from more than one source
- recombinant DNA (transgenic organism)
- States that genes are located on chromosomes and that the behavior of chromosomes during meiosis and fertilization accounts for inheritance patterns.
- chromosome theory of inheritance
- the enzymes that make the covalent bonds between the nucleotides of a new DNA strand
- DNA polymerases
- the transfer of genetic info from DNA into an RNA molecule
- transcription
- the transfer of genetic info in the RNA into a protein
- translation
- small, circular DNA molecules that are separate from the much larger bacterial chromosome
- bacterial plasmids
- DNA carriers that move genes from one cell to another
- vectors
- a technique by which any segment of DNA can be amplified (cloned)
- polymerase chain reaction (PCR)
- a method for sorting macromolecules - proteins or nucleic acids - primarily on the basis of their electrical charge and length
- gel electrophoresis
- human chromosomes contain how many genes?
- 3.2 billion nucleotide pairs of DNA and 30,000 to 40,000 genes
- Fertilization of one plant by pollen from a different plant
- cross-fertilization
- varieties for which self-fertilization produced offspring all identical to the parent
- true-breeds
- the offspring of two different true-breeding varieties
- hybrids
- pairs of alleles segregate (separate) during gamete formation; the fusion of gametes at fertilization creates allele pairs again
- Mendel's principle of segregation
- when an orgaism has a pair of identical alleles for a gene
- homozygous
- when an organism has two different alleles for a gene
- heterozygous
- each pair of alleles segregates independently of the other pairs during gamete formation
- Mendel's principle of independent assortment
- chromosomes other than the sex chromosomes
- autosomes
- hybrids that have an appearance in between the phenotypes of the two parents
- incomplete dominance
- How does codominance differ from incomplete dominance?
- codominance is the expression of both alleles; incomplete dominance the expression of one intermediate trait
- The DNA-containing structures that carry the organism's genes.
- chromosomes
- A complete set of an organism's genes. (Humans have around 35,000 genes.) Located on chromosomes in the cell nucleus.
- genome
- A combination of DNA and protein molecules.
- chromatin
- Consists of DNA wound around a protein core of eight histone molecules.
- nucleosome
- Each chromosome consists of two copies of these before beginning division.
- sister chromatids
- A typical body cell, has 46 chromosomes in humans.
- somatic cell
- The two chromosomes of a matching pair.
- homologous chromosomes
- All body cells in an organism contain two homologous sets of chromosomes.
- diploid organism
- A cell with a single chromosome set.
- haploid cell
- egg and sperm cells
- gametes
- An exchange of genetic material - pieces of chromosomes - between homologous chromosomes, occurs during the first prophase of meiosis.
- crossing over
- These chromosome are called _______ because they result from genetic recombination, the production of gene combinations different from those carried by the parental chromosomes.
- recombinant (chromosomes)
- trisomy 21
- Down's syndrome
- The members of a chromosome pair fail to separate at anaphase.
- nondisjunction
- XXY
- Klinefelter syndrome (male)
- XO
- Turner syndrome (female)
- Organism that has more than two sets of homologous chromosomes in each somatic cell.
- polyploid
- the organs that produce gametes
- gonads
- Cells with the potential to give rise to every type of cell in the body.
- stem cells
- In "The Origin of Species," (1859) Charles Darwin proposed that:
- 1. Modern species descended from ancestral species (descent with modification) and 2. natural selection is the mechanism of evolution.
- The idea that a population of organisms can change over the generations if individuals having certain heritable traits leave more offspring than other individuals.
- natural selection
- How old is the earth?
- 3.5 billion years old
- The comparison of body structures between different species.
- comparative anatomy
- similarity due to common ancestry
- homology
- the comparison of structures that appear during the development of different organisms
- comparative embryology
- consists of all alleles in all the individuals making ap a population
- gene pool
- What produces genetic variation?
- mutations and sexual recombination
- a general formula for calculating the frequencies of genotypes in a gene pool from the frequencies of alleles, and vice versa
- Hardy-Weinberg formula
- A nonevolving population is in genetic equilibrium, also called
- Hardy-Weinberg equilibrium
- Evolution is a generation-to-generation change in a population's frequencies of alleles. Because this describes evolution on the smallest scale, it is sometimes referred to as ______
- microevolution
- a change in the gene pool of a small population due to chance
- genetic drift
- Genetic drift due to a drastic reduction in population size
- the bottleneck effect
- Genetic drift occurs when a few individuals colonize a new habitat. The smaller the colony, he less its genetic makeup will prepresent the gene pool of the larger population from which the colonists emigrated. Genetic drift in a new colony is called ____
- the founder effect
- Apopulation may gain or lose alleles by ____, or genetic exchange between two populations
- gene flow
- the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals
- Darwinian fitness
- a change in life-forms noticeable enough to be evident in the fossil record
- macroevolution
- a population or group of populations whose members have the potential to interbreed with one another in nature to produce fertile offspring
- species
- the origen of new species
- speciation
- domain > kingdom > phylum > class > order > family > genus > species
- taxonomic hierarchy
- both DNA and RNA are nucleic acids which consist of long chains (polymers) of units called
- nucleotides
- DNA and RNA nucleotides are joined by covalent bonds between the sugar of one nucleotide and the phosphate of the next. What is this called?
- sugar-phosphate backbone
- Each nucleotide of DNA or RNA consists of what three components?
- a nitrogenous base, a sugar (deoxyribose, ribose), and a phosphate group
- two polynucleotide strands of DNA
- double helix
- The genetic instructions for the amino acid sequence of a polypeptide chain are written in DNA and RNA as a series of three-base words called
- codons
- RNA nucleotides are linked by the transcription enzyme called
- RNA polymerase
- The nucleotide sequence that says "start transcribing" that the RNA polymerase attaches to is called
- a promoter
- Phase 1 of transcription; the attachment of RNA polymerase to the promoter and the start of RNA synthesis is called
- initiation
- phase 2 of transcription; the RNA grows longer and peels away from its DNA template, allowing the two separated DNA strands to come back together in the region already transcribed
- elongation
- phase 3 of transcription; the RNA polymerase reaches a special sequence of bases in the DNA template called a terminator.
- termination
- the sequence of bases in the DNA template that signals the end of transcription
- terminator
- RNA translation yields
- a polypeptide of amino acids
- what are the two types of mutations?
- base substitutions and base insertions or deletions
- Viruses that attack bacteria are called
- bacteriophages, or phages
- A reproduction cycle of a virus that uses the cell's machinery to produce copies of the virus. The cell lyses, or breaks open.
- lytic cycle
- A virus cycle; the virus DNA inserts by genetic recombination into the bacterium's DNA. The prophage DNA replicates along with the host cell DNA.
- lysogenic cycle
- Once inserted into the bacterial chromosome, the phage (virus) DNA is called a
- prophage
- The synthesis of DNA on an RNA template
- reverse transcriptase