BI 213
Terms
undefined, object
copy deck
- Genome
- -All the genetic information of a cell (all the DNA)
- Chromosome
-
-each is a single DNA molecule and lots of proteins
-each has characteristic shape and size
-humans have 46 - sister chromatids
-
-replication of each chromosome forms 2 sister chromatids
-joined at centromere - Homolog(ous)
- -pair of chromosomes of the same length, centromere position, and staining pattern that possess genes of the same characters
- centromere
- -region of a chromosome where two sister chromatids are attached.
- chromosome set
-
-in diploid cells
-2 sets of each chromosome - diploid
-
-contains two sets of chromosomes (2n)
-One set from each parent - gamete
-
-haploid (n)
-eggs and sperm - interphase
-
-chromosomes duplicated
-start to condense - prophase
-
-chromosomes consist of sister chromatids
-spindle microtubules radiate from centrosomes - prometaphase
-
-spindle captures duplicated chromosomes at centromere region
-nuclear envelope breaks down - metaphase
-
-chromosomes at cell equator
-spindle: pole-to-pole and pole-to-kinetochore - anaphase
-
-sister chromosomes pulled to opposite poles
-other microtubules lengthen, elongating the cell - telophase
-
-chromosomes decondense
-spindle breaks down
-nuclear envelope forms around daughter nuclei - cytokinesis
- -the division of the cytoplasm to form two daughter cells
- polyploid
- -many copies of each chromosome
- autosome
- -chromosomes that are not sex chromosomes
- sex chromosome
- -chromosome responsible for determining sex (xx or xy)
- mitosis
-
-each chromosome is duplicated one time
-cell divides one time
-chromosome sets are conserved - mitotic spindle
- -assemblage of microtubules and proteins that are involved in the movement of chromosomes during mitosis
- microtubules
- -hollow rods composed of tubulin proteins
- centrosome
-
-has two centrioles
-microtubule organizing center - kinetochore
- -at centromere region that links spindles to each sister chromatids
- daughter cells
- -same chromosome content as starting cell
- ploidy
- -number of chromosome sets (1n, 2n, 3n...)
- asexual reproduction
-
-offspring from a single parent
-no fusion of gametes
-offspring genetically identical to parent - sexual reproduction
- -egg cell fuses with sperm cell to form a zygote
- haploid
- -contains one set of chromosomes (n)
- fertilization
- -union of haploid gametes to form a diploid zygote
- zygote
- -diploid product of gametes (a fertilized egg)
- crossing over
- -mixes genetic information from the maternal and paternal chromosomes (nonsister chromatids exchange genetic info)
- synapsis
- -the pairing and physical connection of replicated homologous chromosomes during prophase 1
- independent assortment
- -different alignments at metaphase 1 are equally likely
- genetic variation
- -formed by crossing over and independent assortment
- Meiosis interphase
- -DNA synthesis
- prophase 1
-
-homologs condense and pair
-crossing over
-spindle form - metaphase 1
-
-spindle apparatus attaches to chromosomes
-homolog pairs align on equator - anaphase 1
-
-homologs separate to opposite poles
-sister chromatids stay together - telophase 1 & cytokinesis
-
-one set of chromosomes goes to each pole
-reduction division--no homologs - Meiosis 2
- -No DNA sythesis
- Prophase 2
-
-chromosomes recondense
-spindle fibers form - metaphase 2
-
-spindle apparatus attaches
-chromosomes align on spindle - anaphase 2
- -sister chromatids separate to opposite poles
- telophase 2 & cytokinesis
- -outcome cells are half ploidy of starting cells (haploid)
- true breeding
- -all progeny are the same
- "P"
- parental generation
- F1
- first filial generation
- F2
- second filial generation
- genotype
- -PP, Pp, pp
- phenotype
- -physical traits of an organism
- homozygous
- -PP, pp
- heterozygous
- -Pp
- mutually exclusive events
-
-sum rule
-probability of event 1 OR event 2 will occur= probability of event 1 + probability of event 2 - independent events
-
-product rule
-probability that event 1 AND event 2 will occur= probability of event 1 x probability of event 2 - test cross
- -breeding an organism of unknown genotype with homozygous recessive to determine unknown geno
- progeny
- -offspring
- allele
- -any alternative versions of a gene (P or p)
- locus
- -chromosome location=gene
- law of segregation
- -the 2 alleles for a trait separate during gamete formation
- law of independent assortment
- -allele pairs of different loci segregate independently
- pedigree
-
-diagram of a family tree showing the occurrence of heritable characters in parents and offspring over multiple generations
-dominant trait: affected progeny have affected parents - pleiotropy
- -a single gene affects 2 or more traits
- epistasis
- -interaction of genes that jointly control a single trait
- dihybrid
- -parents differ 2 traits
- carrier
- -heterozygous (Aa)
- hemizygous
- -no equivalent gene on Y
- sex linkage
- -gene physically on a sex chromosome
- wild-type
-
-allele seen commonly in nature
-superscript "+" - mutant
- -recessive
- SRY gene
- -gene critical for sexual differentiation
- X-linked
- -recessive trait
- sex limited traits
- -trait found in only one sex
- sex influenced traits
- -sex hormones affect the trait
- non-disjunction
- -when a pair of homologous chromosomes or sister chromatids fail to separate properly
- aneuploidy
- -extra or missing chromosomes
- X-inactivation
-
-equalize gene expression
-change protein-DNA structure of chromosome
-chromosome stays condensed during interphase
-gene expression is silenced - Barr body
-
-inactive X chromosome
-highly condensed throughout cell cycle - linkage map
- -genetic map based on the frequencies of recombination between markers during crossing over of homologous chromosomes
- trisomy 21
- -down syndrome
- **trisomy 21
- -down syndrome
- recombinants
- -chromosome created when crossing over occurs
- map unit
- -1% recomb=1 map unit=1 centimorgan (cM)
- recombination frequency
- -total # recomb types divided by total # of progeny
- pyrimidines
-
-thymine
-cytosine - purines
-
-adenine
-guanine - adenine
-
-pairs with thymine
-2 hydrogen bonds - cytosine
-
-guanine
-forms 3 hydrogen bonds - base
- -T, A, C, G
- template
- -each strand serves as a template for sythesis of a new strand
- polymer
-
-protein
-DNA - subunit
-
-20 amino acids
-4 nucleotides - sugar-phosphate backbone
-
-outside
-links nucleotides inside - complementarity
-
-A=T
-C=G - RNA primer
-
-made by primase
-start of RNA segment - ribose
-
-in RNA
-extra oxygen - Uracil
- -replaces thymine in RNA
- RNA transcript
-
-RNA copy of a gene
-makes mRNA - promoter
- -determines what strand is being copied and where it starts in transcription
- RNA polymerase
- -binds to the promoter
- ligase
- -enzyme that seals fragments in the backbone
- helicase
- -untwists the double helix of DNA at the replication fork
- peptide
- -covalent bond between two amino acids
- ribosome
-
-made of a few large RNAs and many proteins
-translation machine - genetic code
- -3 bases=amino acid
- translation
- -mRNA into polypeptide
- stop codon
- -no amino acids
- start codon
- -methionine
- introns
- -not coding
- exons
- -code for gene