Non-mendelian inheritance (Biology)
Studied by 0 people
Call with Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play
Podcast1/118
There's no tags or description
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai |
|---|
No study sessions yet.
119 Terms
Mendelian Inheritance rule #1
genes are passed unaltered from cell to cell, and across generations (except in the case of rare mutation)
Mendelian Inheritance rule #2
The genes obey Mendel's law of segregation
what are Mendel's law of segregation?
2 alleles separate as the gametes form, so every gamete receives one allele
Mendelian Inheritance rule #3
for crosses involving 2 or more genes, the genes obey Mendel's law of independent assortment
what is Mendel's law of independent?
alleles of different genes assort independently of each other as the gametes are formed
is Mendelian inheritance true for most genes? what does it also us to do?
yes, allowing us to predict phenotype
Non-Mendelian inheritance rule #1
Epigenetics: genes are passed to offspring are altered not as a change in gene sequence, but as a change in gene expression
Non-Mendelian inheritance rule #2
genes are not in the nucleus do not obey rule number two of mendelian inheritance.
where are the genes that are not in the nucleus located?
In the mitochondria and the chloroplasts
Non-Mendelian inheritance rule #3
Some genes are on the same chromosome and a sort together. (not independent)
what is linkage and recombinations examples of.
Non-Mendelian inheritance rule #3
what is Epigenetic's
The study of mechanisms that lead to changes in gene expression that can be passed from cell to cell and are reversible, but do not involve a change in gene sequence
Can Epigenetic's be passed down across generations
in some cases, yes
what are the 3 epigenetic mechanisms
DNA methylation
Histone modifications
RNA (RNA interference)
what are the characteristics of RNA?
single stranded, cell moves complementary RNA strand. (will stick together and won't proceed transcription)
what is the addition of a methyl group to cytosine or adenine?
DNA Methylation
what does DNA Methylation silence?
most often gene expression
how is DNA Methylation heritable?
through mitosis - sometimes meiosis
what is a histone?
Highly conserved proteins that support DNA and condense it within the cell nucleus
what part of the histone is subject to a variety of modifications?
Histone tails
what is an example of a histone modification?
methylations
what is gene silencing - Mostly (condensed)
methylations
what is gene activation- often (open)
acetylation
what are female honey bees called? Are they haploid or diploid?
queens and workers , diploid
what are male honey bees called?
drones , haploid
what do queen bees eat?
A larva is fed royal jelly
what do Queen bees inhibit?
DNA methylation
what ar characteristics of Queen bees?
many molts, large size, makes ovaries
what are worker bees fed?
larvae are fed a diet of pollen
What do workers bees have a Hugh level of?
DNA methylation
what are some characteristics of worker bees?
few moles, small size
How long do worker bees live for?
they live a fraction of a queens bees lifetime
what leads to increased growth and production of queen bees
Inhibition of DNA methylation
how many genes are differently methylated between workers and queen bees?
550 (5000+)
How is an Epigenetic mark passed down?
passed down across generations
what does a cycloidea gene control
Controls dorsal-ventral symmetry in flowers
what does the peloria mutant do?
cycloidea gene is heavily methylated
what does a toadflax mean
little methylation of the cycloidea gene
what type of inheritance is DNA methylation
Trans generational
what is Epigenetic's 1?
Genomic imprinting
what does Epigenetic's 1 mean?
When a gene is epigenetically marked by Mom (egg) or by Dad (sperm)
what does the offspring express
The offspring expresses either Mom's or Dad's copy of the gene but not both
Is Epigenetic's 1 a non-mendelian inheritance? why?
Yes, because imprinting causes the offering to express either Mom's or Dad's copy of the gene
what is an example of genomic imprinting?
Insulin-like growth factor 2 (Igf2)
what is Insulin-like growth factor 2 (Igf2)?
A hormone needed for growth and development
what happens if Insulin-like growth factor 2 (Igf2) is not expressed (in mice)?
the mouse will be dwarf
how does Igf2 imprint mice genes?
it is imprinted, so that only the paternal copy of the gene is expressed
this is Epigenetic's 2?
X- chromosome inactivation
what are human chromosomes?
autosomes and sex chromosomes? (X.Y)
what is X-chromosome Inactivation
In embryonic development one X chromosome is randomly inactivated in each cell
what is dosage compensation?
Ensures that expression of ex linked genes are the same in both XX and YY individuals
Is Inactive X- chromosomes visible? if so, how?
in some cells, as a Barr body
is inactivation of x-chromosome random in the embryo?
yes
is inactivation of x-chromosome random in the placenta?
no
what does inactivation of x-chromosome look like in the embryonic placenta?
genes are the maternal X chromosome are expressed
the paternal X chromosome is genetically silencened
X chromosomes has a large number of genes associated with immune system
expression on mothers X chromosome only lower risk of immune direction of the embryo.
what is epigenetic 3?
Effects of the environment
what is the agouti gene?
Causes yellow pigment to be positive in hair
what is the agouti gene a loss of?
it Is a loss of function mutant - brown color
what do the fur coats of mice vary with?
methylation of agouti gene
what does feeding female mice a diet rich in B vitamins do?
alters DNA methylation
what were the examined changed of this diet?
Changes in the coat colour of their off spring and differences in methylation of the agouti gene
what are 2 examples of Epigenetics 3 - Effects the Environment
Bisphenol A (BPA) and Fetal liver (human)
what does Bisphenol A do?
disrupts normal methylation patterns
what does Bisphenol A cause
Increases methylation in some regional DNA and decreases methylation in other regions
what do patterns of disruptions of methylation of the DNA differ?
differed among tissues and also between sexes.
what is "Project Ice Storm", Quebec ice storm (1998)
Compared stress levels in a questionnaire of mothers who were pregnant during storm or pregnant within three months following the ice storm
what was compared in the offspring of these mothers?
DNA methylation
hoe many sites of DNA methylation are there? where are they located?
there are 1675 sites, located on 22 chromosomes - immune cells, salivary glands, and other tissues
what is non-mendelian Inheritance II
extranuclear inheritance
which extranuclear inheritance have there own genomes?
chloroplasts (around 100 genes) mitochondria (around 37 genes)
how did endosymbionts evolve?
Evolved as a symbol that were taken up by eukaryotic cells
what does non-mendelian Inheritance II mean rely on?
rely on nuclear genes for some proteins
what is Extranuclear Inheritance 1?
Chloroplast genomes are often maternally inherited
what colour leaves do four o'clock plant's have
Leaves can be green, white or variegated
where does the green colour come from?
chloroplasts
why does chloroplasts give the green colour?
Organelles implant cells that capture energy from the sun and create glucose (photosynthesis)
what depends on the pigmentation of the female parents in offspring?
pigmentation of the offspring (genetically different types of chloroplasts in the leaves)
how do white leaves happen?
a Mutation in a key gene involved in chlorophyll synthesis
what structures do the egg contain?
The egg contains the structures proplastids that will form the chloroplast and offspring
what is sea slugs also known as?
"crawling leaves"
Is this an example of extranuclear inheritance?
no
how does the algae sea slugs eat affect them?
take up the algal chloroplast into their gut which branches through their body
what do sea slugs use photosynthesis for?
to make glucose
What do chloroplast rely on from the alga (food)
rely on proteins from the nuclear genes of the host (sea slug)
How is mitochondria inherited?
Maternally inherited in most eukaryotes
What does mitochondria rely on for proteins
nuclear gene
What are some mitochondrial diseases in human
lebers hereditary optic neuropathway
Neurogenic muscle weakness
Maternal myopathy
Myoclonic epilepsy
what is lebers hereditary optic neuropathway
A mutation in one of several mitochondrial genes - loss of vision
what is Neurogenic muscle weakness?
A mutation in energy needed to make ATP (energy storage) - abnormalities in the nervous system
Note 
Flashcards (84)