Genetic diversity and Adaptation Flashcards
1
Q
What are the three components of nucleotides
organic
A
- A pentose sugar
- A phosphate group
- An organic base
2
Q
Describe the stucture of DNA
What type of sugar? What type of group? What type of bases Double or single stranded? What type of bond between? What shape does it form?
A
Made up of:
- Deoxyribose sugar
- A phosphate group
- 1 of 4 organic bases (A,C,G,T).
- It is double-stranded
- H bonds between the bases form a helix shape
3
Q
Describe the role of DNA
inherited
A
Carries genetic information, determines our inherited characteristics
4
Q
Describe the structure of RNA
What type of sugar?
What type of group
How many bases? and what are they?
double stranded or single stranded
A
Made up of a ribose sugar
- P group
- One of the 4 organic bases (A,C,G,U)
- It is single stranded.
5
Q
Describe the role of RNA
Tranfers
for what?
A
Transfers genetic information from DNA to ribosomes for protein synthesis.
6
Q
Which bases are purine and which are pyrimdine?
A
C
A
Purine (double ring) = Adenine and Guanine
Pyrimdine (single ring) = Cytosine, thymine, Uracil
7
Q
How is DNA in eukaryotic cells different from in prokaryotic cells?
Eukaryotic Cells = 5
differences
Prokaryotic cells = 2
Trigger.
to form
what organelle
Contain what?
A
Eukaryotic cells:
- Found in nucleus
- Long and Linear
- Associated with histone proteins to form
chromosomes. - Mitochondria and Chloroplasts
- Contain prokaryotic-like DNA
Prokaryotic cells:
- Short and circular
- Not assocciated with proteins
8
Q
What is the genetic code?
Order
Consists of?
(
A
The order of bases on DNA. Consits of codons (triplets of bases that code for a particular amino acid.)
9
Q
Identify feature of the genetic code
- Once
- more than one.. Code for..
- Same bases
Triplets
A
- Non-overlapping = each triplet is only read once
- Degenerate = more than one triplet codes for the same amino acid (64 possible triplets for 20 amino acids).
- Universal = same bases and seqeunces used by all species
10
Q
Gene
A section of…
Contains what?
for specfic what?
To make?
A
A section of DNA that contains the coded information for a specific sequence of amino acids to make polypeptides and and fRNA.
11
Q
Locus
DNA
occ
A
The fixed position on a DNA molecule occupied by a gene.
12
Q
Allele
versions
Where are they found?
A
Different versions of the same gene, found at the same locus on a chromosome.
A single gene could have many alleles.
13
Q
What are Exons and Introns?
regions of…
That do what
A
Exons = Regions of DNA that code for amino acid sequences. Seperated by one or more introns
Introns = Regions of DNA that do not code for anything
14
Q
Where are introns found
and..
A
Between exons and within genes
15
Q
DNA and Protein synthesis
A
16
Q
DNA and Protein synthesis
A
17
Q
Genome
complete
contained
A
The complete set of genetic information contained in the cells of an organism
18
Q
Proteome
similar defintion or genome
A
The complete set of proteins that can be produced by a cell.
19
Q
Describe the structure of mRNA.
Short or Long?
Double or single stranded?
What about the base seqeunce?
A
- long
- single strand.
Its base sequence is complementary to the DNA it was transcribed from
20
Q
Suggests advantages of using mRNA rather than DNA for translation
Length & …
no excess what form/
Type of strand & ..
What do organelles do move… and.. t
what does it not contain
A
- Shorter & contains uracill = breaks down quickly so no excess polypeptide forms
- Single-stranded & linear = ribosomes moves along strand & tRNA binds to exposed bases
- Contains no introns
21
Q
Describe the structure of transfer RNA (tRNA).
Around how many nucleotides?
That is folded over into what?
What is one end an?
and the opposite end is what?
A
- A single strand of around 80 nucleotides that is folded over into a clover leaf shape.
- On one end is an anti-codon, on the opposite end is an amino acid binding site.
22
Q
What is produced by transcription?
A
mRNA
23
Q
Where does transcription take place.
A
In the nucleus
24
Q
Outline the process of transcription
What happens to DNA Into how many strands with what?
What is one used as?
- What lines up next to what?
- and joined together by what?
A
- DNA uncoils into 2 strands with exposed bases .One used as a template.
- Free nucleotides line up next to their complementary bases, and are joined together by RNA polymerase
25
What happens to mRNA after transcription?
What must be Spliced and why?
What does it leave?
Then what happens and attached to what organelle.
- In eukaryotic cells, pre-mRNA must be spliced to remove introns, leaving only the coding regions.
- Then it moves out of the nucleus and attaches to a ribosome
26
What is produced by translation
Proteins
27
Where does translation take place
Orangelle to be specfic.
In the cytoplasm (on ribosomes).
28
Outline the process of translation
1. Someones of tRNA attaches to what on what?
2. Something bonded to tRNA form what bond. Continuing to form what until what is reached
What is required?
1. The anticodon of tRNA attaches to complementary baes on the mRNA
2. Amino acids bonded to tRNA form peptide bonds, coninuing to form a polypeptide chain until a stop codon is reached
- This process required ATP.
29
Genetic diversity and Adaptation
-
30
Population
all
particular
All the organims of a particular species that live in the same place
31
Allele
Different versions of the same gene, found at the same locus on a chromosomes.
32
Genetic diversity
total
alleles
The total number of different alleles in a population
33
What advantage does high genetic diversity provide?
ability to what?
allows
Ability to adapt to a change in enviroment: allows natural selection to occur
34
Explain how natural selection results in development of new characteristic
Random
Some ... provide
making the individual what?
offspring recieve this and what?
frequency continues to?
- Random mutations result in new alleles
- Some alleles provide an advantage, making an individual more likely to surive and reproduce.
- Their offspring recieve the new allele, and frequency continues to increase over generations
35
Directional selection
Favours what?
The process where natural selection favours an extreme phenotype
36
When does directional selection take place?
Change
After an environment has experienced a change.
37
Give an example of directional selection
Resistance
- Bacteria with what. Allows them to survive and ...
- What increases and what happens to the population will what and have what..
Antibiotic resistance.
- Bacteria with a mutation allowing them to survive in the presence of antibiotics will reproduce.
- Frequency of this allele will increase and the population will shift to have greater antibiotic resistance.
38
Stabilising selection
Favours who are close to what?
Maintaing...
A type of selection that favours individuals close to the mean, maintaining the traits of the population.
39
Give an example of stabilising selection
Babies
Birth weight; babies that weigh around 3kg are more likely to survice than those lower or higher weights
40
# Define a niche
Role..
The role of species within its enviroment. Species sharing the same niche will compete with each other
41
What are the 3 types of adaptations? Give examples of each
- Strucutre
- Processes
- Actions
Changes
- Anatomical (changes to body structure) e.g. oil fur
- Physiological (changes to bodily processes) e.g. venom production
- Behavioural (changes to actions) e.g. hibernation
42
Selection pressure
An external factor that influences the reproductive success of an individual.
43
Example of Selection pressure
Disease acts as a selection pressure that increases the reproductive success for individuals who are immune to the disease.
44
What phenotype is favoured in bacterial populations that are exposed to antibiotics?
Antibiotic resistance
45
What type of environment does stabilising selection take place in?
Non-changing enviroment
46
Describe how an adaptation, such as better running speed, relates to natural selection.
Natural selection reproduces individuals with favourable genetic traits-such as adaptation of better running speed-over time
47
Adaptions
A feature of an organism that increases its chance of survival in its environment. An adaptation may be anatomical, physiological or behavioural.
48
Aseptic techniques include:
Disinfect surfaces.
Sterilise equipment to destroy microorganisms.
Flame the necks of bottles on opening.
49
Stages involved in investigating Microbial growth:
1. Make sure the conditions for experiment are aseptic
2. Spread the bacteria onto a petri dish
3. Place antibiotic ring on the petri dish
4. Place lid on the petri dish and loosely secure the lid with tape
5. Incubate the petri dish upside down for 24-48 hours
6. Observer the growth pattern of bacteria
50
Why should you make sure your conditions for the experiment are aspect?
To prevent the growth of any unwanted microorganisms that might affect the results
51
Why should you use a pure culture of bacteria?
To make a lawn spread on a petri dish
52
Why should you secure the petri dish loosely with tape?
To allow the flow of oxygen and prevent the growth of anaerobic bacteria
53
Why should you incubate the petri dish upside down?
To prevent condensation from dripping onto the agar
54
OBSERVE GROWTH PATTERNS
you should a zone of inhibition around the antibiotic ring where no microorganisms have grown. What should you do?
Measure of zone of inhibition
55
What can inferred from there being a greater number of different alleles in a population
A greater genetic diversity in that population
56
What are two ways in which genetic diversity in a population is increased?
Mutations
| Gene flow
57
The presence of genetic variation in a population allows what process to take place
Natural selection
58
What is the name of the process in which natural selection favour an extreme phenotype
Directional selection
59
What should be seen after incubation when investigating the effect of anti microbial substances on the growth of microorganisms?
No organisms growth around the antibiotic ring
60
What type of selection takes place in environments that do not change
Stablising
61
Species and Taxonomy
-
62
Species
A group of organims that can interbreed to produce fertile offspring
63
What are the advantages of courtship behaviour
Individuals can recognise sexually mature members of their species of the opposite sex, synchronise mating, form a pair bond and successfully breed.
64
Define classification
The process of arranging organisms into groups
65
Name the 8 groups an organism can be classified into, from largest to smallest.→
Domain → kingdom → phylum → class → order → family → genus → species
66
What system is used to give species a universal name?
Binomial naming system
67
What are the 2 components to a bionminal name?
Generic name = the genus the organism belongs to. Two closely related species will share the same genus
Specific name = the species the organism belongs to.
68
How are bionomiaal naes handwritten
The first letter of the generic name should be capitalised, with the rest in lowercase, The whole name should be underlined.
69
What is phylogenetic classification?
The process of arranging organims into groups based on their evolutionary origins and relationships.
70
How can we clarify evolutionary relationships between organims?
Analuse their molecular difference.
Advances in immunology/genome sequencing provide clear pictures of how related 2 organims are.
71
Explain hierachial classfication
Groups within groups where there is no overlap between the groups.
72
Species richness
A measure of the number of different species in a community at a given time. It is a measure of species diversity.
73
Courtship
The behaviour by which members of a species select reproductive partners. It enables organisms to recognise their own species, identify a mate with a capacity to breed,form a pair bond, synchronise mating and become able to breed themselves.
74
Example of courtship behaviours
E.g. The male superb bird of paradise spreads its wing and dances to attract a female.
75
Why is it important for organisms with the same species to breed
so that they can pass their genes to their offspring.
76
What name is given the complex displays helps an individual to find a mate?
Courtship behaviours
77
Phylogenies
used to understand the evolutionary relationships between organisms. Phylogenies can help classify organisms
78
In a phylogenetic tree, what does the point where two branches join represent?
Common ancestor
79
Courtship behaviour takes place before mating and enables individuals to:
- Recognise members of their own species
- Synchronise mating
- Form a pair bond
- Become able to breed
80
The scientific community evaluates the data in the following ways:
* The findings are published in scientific journals and presented scientific conferences.
* Scientists then study the evidence in a process called peer review
* Scientists start collecting evidence to either support or reject the suggestion
81
What are closely related organisms that are grouped together called?
singular = Taxon
82
Genus
The taxa in which Homo and Panthera are classified within.
83
Taxa
Groups in which closely related organisms are grouped together.
84
Hierarchy
The series that each taxon is arranged into.
85
Kingdom
The taxa in which animals, plants and fungi are classified within.
86
What helps clarify evolutionary relationships
Genome sequencing (e.g. the relationship between skunks and weasels).
87
How does the biodiversity at the equator differ to the biodiversity at the poles?
The equator is typically biodiverse than the poles
88
Biodiversity
The variety of living organism. It can be measured in terms of species diversity (number of species in a community.) Ecosystem diversity (range of different habitats) and genetic diversity.
89
Define community
All the different species that live in one area and interact with each other
90
How do you calculate index of diversity (d)?
d = N(N-1) / Σn(n-1)
N = total numbers of organims of all species
Σ = sum of
n = total number of organims of each species
91
What impact does farming have on species diversity?
Decreases species richness
- Farmland is typically used for only 1 species (monoculture)
- use of pesticides/ herbicides
92
What impact does farming have on genetic diversity
Decreases
- Farmers select for certain characteristics, which reduces number of different alleles in the population.
93
How can biodiversity be increased in areas of agriculture?
1. Use hedgerows instead of fences
2. Grow different crops in the same area, or rotate crops around after a season.
3. Limit use of pesticides and herbicides
94
Name 4 ways we can measure genetic diversity?
1. Frequency of observable characteristics
2. Base sequence of DNA
3. Base sequence of mRNA
4. Amino acid sequence
95
Gene technology
Sampling DNA or mRNA in order to read and compare the base sequence of organims. Alternatively the amino acid sequence can be studied as this will also provide informaton on the organism's mRNA and DNA sequences.
96
Why do scientists prefer to use gene technology instead of observation?
Simply inferring DNA difference by obsevering an organim's characteristics is not reliable; the characteristics could be coded for by more than one gene, or could be influenced by the enviroment.
97
What is it meant by interspecific and intraspecific variation?
Interspecfic = differences between individuals of different species
Intraspecific = differences between individuals of the same species.
98
Sampling
Selecting a group of individuals to measure that will represent the whole target population
99
How can a random sample be achieved?
Creat a gride for you sample area and then randomly generate coordinates where a quadrat or transec can be places. Repeat until required sample size is reached.
100
Calculate how many a change in one base along a DNA molecule may result in an enzyme becoming non-functional
101
Explain how the considerable length of a DNA molecule is compacted into a chromosome
The double-helix is tightly colied around the histone proteins
102
What is the function of a histone protein?
To associate with the DNA to assist in tightly coiling of DNA to fit chromosomes into the nucleus
