Component 2 Flashcards
(119 cards)
1
Q
Acrosome reaction
A
Acrosome enzymes digest the corona radiata and the zona pellucida
2
Q
Allele
A
A version of a gene at a given locus which codes for an altered phenotype
3
Q
Allele frequency
A
Proportion of all the genes in the gene pool
4
Q
Allopatrick speciation
A
Revolution of a new species from isolated populations by a geographical boundary
5
Q
Capacitation
A
Removal of glycoproteins and cholesterol coat which increases permeability of the membrane to Ca+ and increases chances of bonding to allow acrosome reaction to occur
6
Q
Carrier
A
Heterozygous for one dominant allele and one mutant recessive allele
7
Q
Cortical reaction
A
Fusion of cortical membranes with oocyte membrane due to calcium ions being transported into the cytoplasm for SER. This causes zona pellucida to expand and harden
8
Q
Dehiscence
A
Opening of the anther releasing pollen grains
9
Q
DNA ligase
A
Enzyme that joins together portions of DNA by catalysing the formation of a phosphodiester bond
10
Q
Dormant
A
Active growth of the seed is suspended
11
Q
Electrophoresis
A
Separates molecules on the basis of size by rate of migration under an applied voltage
12
Q
Epigenetics
A
The control of gene expression by modifying DNA or histories which does not effect the nucleotide sequence
13
Q
Evolution
A
Change in allele frequency and the average phenotype of the population over time
14
Q
Founder effect
A
The loss is genetic variation in a new population established by a very small number of individuals from a larger population
15
Q
Fruit
A
Structure developing from ovary wall containing one or more seeds
16
Q
Gene
A
Sequence of dna that codes of a polypeptide and occupies a specific locus on a chromosome
17
Q
Gene pool
A
All alleles present of all the individuals in a population at a given time
18
Q
Genetic drift
A
Change in allele frequency due to chance in a small population
19
Q
Germination
A
When the seed becomes a photosynthesising plant
20
Q
Hybrid
A
Off spring is a cross of different species
21
Q
Linked
A
Genes are on the same chromosome and therefore do not segregate independently in meiosis
22
Q
Non disjunction
A
Fault cell divisions no in meiosis where one of the daughter cells receives two copies of one chromosome and the other receives none
23
Q
Plasmid
A
Small circular loop of DNA bacteria which is double stranded
24
Q
Polyploidy
A
Having more than two complete sets of chromosomes
25
Primer
Single strands of DNA complementary to larger section of DNA that is going to be copied. Signals polymerisation to start
26
Recombinant DNA
DNA produced by combining DNA from two different species
27
Reproductive isolation
Prevents reproduction and gene flow between breeding groups in a species in an environment
28
Restriction endonucleases
Cuts sugar phosphate backbone at specific restriction sites
29
Reverse transcriptase
Catalysed the synthesis of DNA from an RNA template
30
Seed
Contains an embryo and food store within a testa
31
Sex linkage
Gene is located on X chromosome so is more likely in males than females
32
Speciation
Formation of a new species
33
Species
Group of organisms that can interbreed to produce fertile offspring
34
Stem cell
Undifferentiated cell capable of diving to give rise to daughter cells which can develop into any type of cell
35
Sticky end
Sequence of unpaired bases which are staggered and exposed
36
Sympatric speciation
Evolution of a new species from populations sharing the same environment
37
Test cross
Cross with homozygous recessive
38
Transgenic
Organism genetically modified by the addition of genes from another species
39
Trophoblast
Cells forming outer layer of blastocyst
40
Variation
Difference between organisms of the same species
41
Mitosis
Cell devision forming two genetically identical daughter cells with same number of chromosomes
42
Classification
Organisation of organisms into groups according to shared similarities
43
3 domains
Eubacteria
Archea
Eukaryotes
44
Analogous
Same function but different structure = not related
45
Homologous structures
Same structure different functions = divergent evolution
46
Biodiversity
Number of species and number of organisms of each species in an environment
47
3 types of adaptations
Anatomical (body shape = streamlined)
Physiological (leaves fall of with low light intensity and cold)
Behavioural (flowers in spring with pollinating insects)
48
Interstitial cells
Secrete testosterone for secondary sex characteristics
49
Sertoli cells
Nourish cells and protect from immune system
50
Solid ball of cells
Morula
51
First hormone secreted
GnRH
52
Function of progesterone
Produced from corpus luteum
| Maintains endometrium and inhibits FSH
53
Function of oestrogen
```
Builds endometrium
Inhibits FSH
Stimulates LH
Secondary sex characteristics
Inhibits prolactin and oxytocin
```
54
Function of FSH
Stimulates Graafian follicle
Stimulates oestrogen
I’m
55
2 synergid cells
Aid ferlisation
56
3 antipodals
Direct nutrients
57
Pollination
Transfer of pollen grains from another to nature stigma
58
Self pollination
Pollen from anther is transferred to stigma of same flower or plant
59
Cross pollination
Pollen transferred from anther to stigma on a flower of a different plant of same species
60
Ensuring cross pollination
```
Dichogamy
Anther below stigma
Male and female flowers
Male and female plants
Genetic incompatibility
```
61
Why is maize a fruit
Testa fuses with ovary wall
62
What is the testa formed from
Integuments and lignin
63
Codominant
Both alleles have an affect on phenotype of heterozygous as both are expressed eg. Blood type AB
64
Incomplete dominance
Phenotype of the heterozygous is half way between the two alleles
65
Dihybrid cross
Cross between two individuals for two genes of different chromosomes
Assumes all allele combinations are equally likely and down to random assortment
66
Recognising linkage
Cross over value
| Kai squared
67
Critical value
Degrees of freedom = number of sums -1
| Use 0.05 probability value
68
Mutations
Change in amount arrangement structure of DNA
69
When do mutations occur
Crossing over in prophase 1
| Non disjunction in anaphase 1/2
70
Increased rate in mutations
Ionising radiation
| Mutagenic agents eg. Agent orange
71
Type of mutations
Genepoint
Chromosome
Aneuploidy
Polyploidy
72
Gene point mutation
DNA not copied correction
73
Chromosome mutation
Damaged or broken chromosome not repaired correctly
74
Aneuploidy mutation
Chromosome is lost or added through non disjunction
75
Polyploidy mutation
Double number of chromosomes due to
- endomitosis
- fusion of two haploid cells
- defect in spindle fibres
76
Types of gene mutation
```
Substitution
Addition
Deletion
Inversion
Duplication
```
77
Sickle cell anaemia
```
Substituting of val to glu
Change in tertiary
Insoluble
Stick together
Sickle shaped
Reduces oxygen binding
```
78
Chromosome mutation
Change in structure and number of whole chromosomes
| Eg. Breaks and doesn’t rejoin or non disjunction
79
Down’s syndrome
Down’s syndrome
Extra chromosome 21 from nondisjunction of oocyte
Translocation downs when a bit breaks off and attaches to another chromosome
80
Proteins that’s regulate cell division
Protooncogenes
| Tumour suppressor genes
81
Malignant cancer
Cells break off and travel in blood to form secondary tumour = metastasis
82
2 ways of epigenetixs
Histone modification
| DNA methylation
83
4 types of variation
Heritable
Non inheritable
Continuous
Discontinuous
84
Heritable variation
Mixing of parental genotypes
Crossing over
Random assortment
New allele combinations
85
Non inheritable
Environmental influences determine phenotype
Eg. Diet exercise
Not passed on
86
Continuous
Multiple genes polygenic
Graduation between extremes
Genetic and environmental
87
Discontinuous
Single gene mono genic
Discreet variables
Genetic only
Not gradation
88
Causes of variation
Mutation
Crossing over
Independent assortment
Random gamete formation
Environmental influence on cytoplasmic level (non inheritable)
Environmental influences on gene expression (epigenetics)
89
4 types of selective agents
Environmental factors eg. Fire global warming
Human influence eg. Antibiotics weed killers
Inter specific competition
Intraspecifc competition g
90
3 types of selection
Stabilising
Directional
Disruptive
91
Selection pressure
Environment factor that can alter the frequency of alleles in a population when it is limiting
92
Natural selection
Increased chance of survival and reproduction of organisms with phenotypes suited to their environment enhancing the transfer of favourable alleles between generations
93
Selection
Process that better adapted organisms are more likely to survive and breeed and pass on characteristics
94
Bottleneck
Disaster killed all by few individuals which changes alleles frequency
95
How many new species arise
Polyploidy
| Isolation = restriction of gene flow
96
Reproductive isolation
Prevent of reproduction and gene flow between breeding groups in a species
97
Prezygotic isolation
```
Geographical
Behavioural
Morphological
Gamete isolation
Seasonal
```
98
Postzygotic
Hybrid inviability
Hybrid sterility
Hybrid breakdown
99
Harvey Weinberg features
```
Large population
No mutations
Random mating
No selective agents
No immigration or emigration
```
100
Harvest Weinberg equations
```
P = frequency of dominant allele
Q = frequency of recessive allele
P2 probability of homozygous dominant
Q2 probability of homozygous recessive
2pq probability of heterozygous
```
101
Sanger sequencing
```
Cut up DNA
Add dideoxynueotide to present polymerisation
Mark end nucleotide with marker
Add stop nucleotides
Gel electrophoresis
```
102
Aims of human genome
determine order of bases in genome
| Identify genes and mapping
103
Chloroquine
Delays haemoglobin digestion by the parasite
104
Getting the vector
EDTA to destabilise cell wall
Detergent
NaOH
Centrifuge
105
Two gene markers
Amphicillin
| Tertracycline
106
Where is the gene for insulin
In tetracyline gene
107
GM tomatoes
Add gene with complementary sequence to the gene that codes for pectin which break down the tomatoes
108
Gene therapy
A working copy of the gene in placed into cells that contain a non functioning gene or repair gene by changing expression
109
Somatic cell therapy
Replacing fault genes with correct copies in certain body tissues so genes can’t be inherited
110
Germ line
Gene is inserted into embryo or gamete or all new cells contain new gene
111
Duchenne muscular dystrophy cause
Deletion creates frame shift
Lack of dystrophin so muscles break down and are replaced by fibrous tissue and fatty deposits
Sex linked m
112
Treatment for DMD
Drisapersen injections which restore reading frame by being complimentary to the mutated DNA part so section is not translated
113
Autologous cells
Cells from same individual
114
Allogenic cells
Donor of same species
115
Xenogenic
Cells from another species
116
Synergic cells
From genetically identical organism
117
Benefits of a scaffold
Cells can attack
Delivers and retains cells
Porous for diffusion
Biodegradable
118
Types of stem cells
Embryonic
Adult
Genericalll reprogrammed by viruses
119
Uses of stem cells
Tissue engineering
Cell based therapies
Screen for new drugs
