Please enable JavaScript.
Coggle requires JavaScript to display documents.
Ch 16 Genetics (Mutations (Causes of Mutations (Insertion Sequences…
Ch 16 Genetics
Mutations
Causes of Mutations
Mutagen
something that causes a mutation
Insertion Sequences
contains genes that code for enzymes
involved in cutting insertion sequence
& splicing it into DNA somewhere else
transposon
like insertion sequence
carries genes that code for proteins
Effects of Mutations
depends on
nature
position
extent
mutations are almost always harmful
natural selection eliminates the deleterious one and preserves the beneficial one
Somatic Mutations
happen in cells that never lead to sex cells
eventually becomes sexual cell
DNA Repair Process
must be neither too efficient nor too ineffective
repairing can cause serious problems
Mutation
any change in DNA
Point Mutation
smallest mutation affecting least amount of DNA
single base is converted to another base
Deletion
pieces of DNA is lost
Insertion
addition of extra DNA
Inversion
put in backwards
Replication of DNA
DNA replicated in S phase
replicon
small bubble where strands separate from each other
primer RNA
ribonucleotides are polymerized into short pieces
DNA Polymerase
primer RNA act as DNA-synthesizing enzyme
semiconservative replication
each DNA strand acts as template for making the complementary strand
replication fork
DNA coils and separates looks like fork :fork_and_knife:
ligated
attached with covalent bonds
Monohybrid Crosses
Monohybrid Crosses with Incomplete Dominance
monohybrid cross
single character is analyzed and studied
parental generation
parents
F1
offspring of the parents
F2
offspring of F1
homozygous
two identical alleles for a gene
heterozygous
two different alleles for one gene
incomplete dominance
heterozygous phenotype differs from both homozygous phenotypes
Crossing Heterozygous with Themselves
Selfing
plant's own pollen is used to fertilized its eggs
Punnett Square
test that can be used to test genotypes and phenotypes
does not represent outcome of any one cross, just posibilility
Monohybrid Crosses with Complete Dominance
dominant
phenotype of the heterozygote is like the parent of the effective alleles
recessive
other possible phenotype of the heterozygote that is less likely to be than the dominant
Test Cross
complete dominance
presence of one allele completely makes presence of homologous allele
Test Cross
cross involving one cross known to be homozygous recessive for the trait being considered
pure-bred lines
homozygous dominant
must be made on annual plans
Multiple Alleles
multiple triple alleles
900 existing sites
polymorphic
subscripts are uses
Cross
sexual reproduction between individuals
Dihybrid Crosses
Genes on Separate Chromosomes: Independent Assortment
independent assortment
alleles of one gene moved independently of the alleles of the other genes
Crossing Over
Genes on the Same Chromosome: Linkage
linked genes
genes located close to each other on a chromosome undergo crossing over only rarely, so they're linked
linkage group
set of genes that do not undergo independent assortment, being part of one chromosome
recombinant chromosomes
formed from crossing over of the homologous chromosomes and recombination of alleles
parental type chromosomes
map unit
measure of separation of genes on a chromosome
one equals 1% of probability that crossing over will occur between them
cross in which two genes are studied and analyzed simultaneously
Multiple Genes for One Character: Quantitative Trait Loci
epistasis
having multiple genes for each trait
quantitative trait loci
phenotypes that vary in degree and can be attributed to polygenic effects
pleiotropic effects
multiple phenotype effects of one mutation
Other Aspects of Inheritance
Maternal Inheritance
biparental inheritance
alleles of both parents are transmitted equally to progeny
uniparental inheritance
(Maternal Inheritance)
zygote obtains all its plastids and mitochondrion genomes from maternal parent
pollen parent and ovule parent :question:
variegation
pattern of spots, stripes, or patches in leaves or other organs, caused by plastid mutations
Lethal Alleles
can be difficult to detect in early stages
its presence can kill a plant
Multiple Sets of Chromosomes and Gene Families
polypoid
plants with more than two sets of chromosomes
paralogs
genes within single species that evolved from same ancestral gene
gene family
set of several copies of an ancestral gene
all located within a single haploid genome
various copies happen through duplication and may evolve independently
