chap 20 Flashcards
genome
all of the DNA of a person, ALL 23 CHROMOSOMES IN NUCLEUS
complete set of genes (DNA) or genetical material
genetic engineering
the manipulation of DNA sequences in organisms, (remove pieces of DNA from an organism, sequence and manipulate them and insert them back into cells)
recombinant DNA technology
techniques used to engineer genes, (make new combinations of DNA)
DNA cloning
ability to produce many copies of a gene or other DNA sequence of interest. (in recombinant DNA technology, its referred to DNA cloning)
(restriction enzymes, specific cut site, protect)
inserting gene into plasmid
plasmid
researchers clone a sequence of DNA by inserting it into a small circular molecule called the plasmid.
cloning vector or vector
when a plasmid is used to make copies of foreign DNA sequence
(billions of copies of an original cell each containing versions of the recombinant plasmid DNA)
small Rings of DNA (plasmids) that (Transport gene into a cell)
restriction endonuclease
is a bacterial enzyme that cuts DNA molecules at specific base sequences called recognition sites.
ligase
the enzyme that connects Okazaki fragments during DNA replication (technique in recombinant DNA technology)
using plasmids in cloning
- Identify a recognition site. Plasmid (left contains a recognition site for a restriction endonuclease. The same recognition sites are present on the DNA (right) that will be inserted into the plasmid.
- Add restriction endonuclease.
A restriction endonuclease makes staggered cuts at each of the recognition sites. - Sticky ends result. Recognition sites now have “sticky ends” capable of hydrogen-bonding with a complementary sequence.
- Insert gene into plasmid. Sticky ends on plasmid and on gene bind by complementary base pairing. DNA ligase catalyzes formation of a phosphodiester bond at points marked by green arrows,
“sealing” the inserted gene. - Transformation and cloning.
Introduce recombinant plasmids into
E. coli cells by making cells permeable to DNA. Each cell contains one type of recombinant plasmid. Each cell is allowed to divide, producing many copies (clones) of the recombinant plasmid.
complementary DNA or cDNA
DNA is produced from RNA. (catalyzes the synthesis of DNA from an RNA template)
(although it usually synthesizes a single-stranded cDNA it can also synthesize the complementary strand to yield a double-stranded DNA.)
transgenic
plants by introducing foreign DNA into a plasmid carried by a bacterium. (naturally infects plant tissue using techniques) (next card see, explanation helps) These transgenic plants can be used for research or to create a genetically modified (GM) crop.
genetically modified (GM) crop
researchers can insert recombinant genes into target plant cells, test the cells to identify those that express the recombinant genes, then use tissue culture techniques to start growing these cells into adult plants with a novel genotype and phenotype.
(transgenic plants can be used for research or to create a genetically modified (GM) crop.)
polymerase chain reaction
PCR is an in vitro DNA synthesis reaction that uses a DNA polymerase to replicate a specific section of DNA over and over. (just like inserting a gene into a plasmid is one method for making identical copies of particular region of DNA caled (DNA cloning) , PCR IS ANOTHER METHOD)
when PCR is possible
when a researcher already has some info about DNA sequences that surrounded the DNA, (sequence info is required)
DNA printing (DNA profiling or DNA typing)
refers to any technique of identifying individuals based on the unique features of their genomes.
Short tandem repeats (STRs) known as microsatellites or simple sequence repeats (SSRs)
repeating units that are just 2 to 6 bases long
(for example, one of the STR used in DNA profiling is GATA which is repeated 5 -16 times
(used more than VTNRs because it is shorter and easier to amplify by PCR.
minisatellites or variable number tandem repeats (VTNRs)
repeating units that are 8 - 100 bases long.
dideoxy sequencing
an in vitro DNA synthesis reaction that can determine the base sequence of DNA
next-generation sequencing
have made it possible to rapidly determine the sequence of entire genomes.
downside is that they produce short sequences reads of only 50-200 nucleotides, making it hard to piece together a whole genome,
but if a complete genome sequence is available in organism then its remarkly quick and inexpensive to find the entire genome from an individual.
shotgun sequence
many copies of a genome are broken up randomly into a set of fragments of various sizes, the DNA fragments are sequenced, and the regions of overlap can be used as guides to put the whole genome back together. in process called (genome assembly)
bioinformatics
a field that fuses mathematics, computer science, and biology to manage and analyze sequence data.
genome annotation
identify which regions constitute genes and other functionally important sequences, recalls that a gene is a segment of DNA that both regulate the production of and codes for a functional RNA or protein product.
open reading frame or ORF
a good indication of a protein-coding sequence
homology
similarities in sequence and in function between genes in different species are usually due to homology.
IF GENES ARE HOMOLOGOUS, it means they are similar bc they are related by descent from a common ancestor.
expressed sequence tag or EST
used to locate the gene that encoded the mRNA, researchers use sequence matching programs to search for matches between the EST and a sequence in genomic DNA, having more gene identification and discoveries. (gene-finding strategy)
metagenomics or (environmental sequencing)
cataloging all the genes present in a complex community of prokaryotes.(unicellular)
transposable elements
DNA segments that can insert into new locations in a genome.
long interspersed nuclear element (LINE)
code for reverse transcriptase like retroviruses do and have a similar way of inserting into and exciting from the genome.
gene duplication
occurs when biologists find groups of genes that are similar in sequence and in other features such as the arrangement of exons and introns. (exons=coding, introns=noncoding)
gene family
when genes are similar to each other in structure and function they are considered to be part of the ^
duplication and divergence
processes that create new genes (LOOK more into txtbook, pg 409)
pseudogene
a member of a gene family that resembles a working gene but does not code for a functional product because of a mutation.
Human Genome Project
required more than 15 years and $3 billion to assemble the first human genome sequences
alternative splicing
one hypothesis to explain the discrepancy between genome size and organismal complexity
allows DNA to code for more than one protein. It varies the exon make-up of the messenger RNA. In alternative splicing the exons of the pre-messenger RNA produced by transcription are reconnected in different ways during RNA splicing.
