Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ENV Ecology > Genetics > Flashcards

Genetics Flashcards

1
Q

What are the 6 ways genetic tools can help environmental biology

A

Resolving taxonomic uncertainty to identify species (turtles)
Rescue populations from inbreeding
Manage captive breeding individuals
The role of sex in ecology or captive breeding
Identify pathogens
Forensics can be used to solve wildlife crimes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the principles of genetic tools?

A
  1. Use a site/locus on the genome that differs at the level you need to understand/ identify (level of polymorphism)
  2. Generate suffcient DNA at that site/locus
  3. Sequence the DNA at the site of interest
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a marker loci?

A

A ‘gene’ sequence located at the sequence-specific site in a genome. Can be coding or non-coding DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Whats the difference between coding and non-coding DNA

A

Coding DNA is less variable: useful for comparing between species (e.g mitochondrial enzyme genes like cyctochrome b
Non-coding DNA is highly variable : useful for comparing between populations or individuals as it allows for hidden mutations (e.g microsatellites showing high variation between individuals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 5 core ‘ingredients’ required to set up a PCR.

A

The DNA template that needs to be copied
DNA nucleotides to produce the new chains
Primers to bind to each end of the DNA that needs to be copied
Taq polymerase to add on the new bases
A buffer to ensure the conditions remain optimal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe a PCR

A

DNA is denatured at 94 Celsius and the strands separate.
Temp. lowered to 54 celsius to allow synthetic primers to anneal
Temp raised back up to optimal temp 72 for taq to allow extension and DNA reforms at the locus of interest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is phyletic speciation

A

It is the process of gradual change in a single population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is divergent speciation

A

the divergence of one species into two or more descendant species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is extinction

A

The end of an evolutionary lineage (population, Species, Genus, Family)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

If extinction rates are currently exceeding speciation rates , what is the result?

A

Loss of biodiversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are individual and population phenotypes struggling?

A

REDUCED POPULATION SIZES
CONSTRAINED POPULATION MOBILITY
INCREASED ENVIRONMENTAL STRESS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does phenotypic expression depend on?

A

dominance and heterozygosity within the alleles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why is genetic diversity good? 2 reasons

A

Genetic variation / heterozygosity allows adaptability to environmental stress / change = evolutionary potential

prevents expression of deleterious homozygous recessive genes which prevents inbreeding depression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is genetic variability maintained

A

Through recombination and sexual reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the consequences of a highly inbred population

A

reduced heterozygosity /increased probabability of parents sharinf identical alleles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is reduced heterozygosity bad

A

It increases the chance of parents sharing common alleles which will increase the expression of genes in their homozygous form

17
Q

Why are homozygous genes bad

A

Homozygous genes persisit in the genome with low expressions so they are rarely selected against so tend to code of sub=perfect phenotypic traits

18
Q

Examples of deleterious homozygosity

A

Cystic fibrosis
sickle cell anaemia
red green coour blind

19
Q

What is fitness`

A

is a measure of survival and reproductive success in the natural environment

20
Q

What are the consequences of inbreeding

A

is a measure of survival and reproductive success in the natural environment
= Inbreeding depression of fitness

21
Q

How does inbreeding depression manifest?

A 
Infertility
Abnormal sperm
Reduced clutch size/hatching success 
Embryonic mortality
Offspring survival
Disease susceptibility
General survival under extreme selection
Local extinction
22
Q

Example of inbreeding not reducing fitness

A

Current population of black robins descended from 1 breeding female with a bottlenecked population of 5 birds. The descendants show no minisatellite DNA variation but overall their survival rate is normal

23
Q

What is heterosis

A

improved or increased function of any biological quality in a hybrid offspring.

24
Q

What is outbreeding depression

A

When very genetically different organisms breed. Can occur when local adaptations are disrupted within a species, or when newly-formed species are hybridised

25
Q

Example of inbreeding depression

A

Deer mice Jimenez et al. 1994
captured in wild, then inbred or not in lab
n=367 inbred and n=419 non-inbred released
inbred survived at rate only equal to 56% of non-inbred
inbred lost weight after release, non-inbred maintained weight

26
Q

How can outbreeding depression manifest

A

Intermediate genotypes are not adapted to either parental habitat.
Breakdown of biochemical or physiological compatibility.

27
Q

How can molecular makers help in conservation policy

A

mitochondrial DNA analyses was used to determine the species status for the Kemp Ridley sea turtle and the olive Ridley sea turtle. Scientists were unsure of their relatedness, but analyses showed that their mtDNA was distinct enough to be considered for separate protection under the US Endangered species act

28
Q

What is introgession?

A

It is the movement of a gene (gene flow) from one species into the gene pool of another by the repeated backcrossing of an interspecific hybrid with one of its parent species

29
Q

Example of how genetic tools can help with the issue of introgression

A

Enzyme and mitochondrial data indicated that the cut throat salmon was hybridising with non native salmon which is contributing to their population decline and native populations become isolated from each other. Introgessed populations were removed by conservation efforts to encourage native individuals to breed with each other

30
Q

Limitations to genetic monitoring

A

added expense, particularly with non-invasive samples, owing to the need to repeat genetic analyses to reduce genotyping errors
genotyping errors, if not adequately controlled, impede accurate estimates of many metrics e.g multifold overestimates in abundance
genetic monitoring efforts that rely on non-invasive samples are more vulnerable than are traditional monitoring to fraud

31
Q

What is genetic monitoring

A

he use of molecular markers to (i) identify individuals, species or populations, or (ii) to quantify changes in population genetic metrics (such as effective population size, genetic diversity and population size) over time.

32
Q

example of genetic monitoring used fraudulently

A

Controversy over a lynx survey done in the U.S. rub pads were used to to collect lynx fur and sent to a lab for DNA analysis. There is some evidence to say that some of the presented data came from captive lynxes and not wild ones. It is easier to plant a spurious genetic sample than a live individual Dalton 2002

33
Q

Example of using molecular markers to define population viability

A

Mircosatellites were used to measure genetic diversity after a significant bottleneck in koalas

34
Q

Limitations to RAPD markers

A

the least informative of all known DNA markers; rarely detect heterozygosity
Very sensitive to reaction conditions so results are often laboratory dependent cus enxyme reaction
Amplification products are not always reproduce-able
Co migration can occur

35
Q

What is RAPD

A

RAPD is a modification of the PCR in which a single, short and arbitrary oligonucleotide primer, able to anneal and prime at multiple locations throughout the genome, can produce a spectrum of amplification products that are characteristics of the template DNA

36
Q

What can RAPD be used for

A

gene mapping, population genetics, molecular

evolutionary genetics, and plant and animal breeding

37
Q

Example of saving an inbred population

A

An isolated population of adders in Sweden nearly went extinct due to inbreeding depression; a high proportion of offspring were stillborn or deformed. 20 males were introduced into the area for 4 mating seasons before being returned. In the following years the adder population grew rapidly and DNA analysis showed increased genetic variability

38
Q

What does RAPD stand for

A

Random amplified polymorphic DNA

ENV Ecology (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions