Bio Grade 10 > Lesson 7 > Flashcards

Lesson 7 Flashcards

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1
Q

What is evolution

A

Evolution is the development of new types of living organisms from ones that already exist to the gradual buildup of genetic differences

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2
Q

Where does evidence for evolution come from ( 2 )

A

Observing anatomical features shared between organisms (including ones that are visible only during development) can indicate that they share a common ancestor.

Traits that are shared due to common ancestry are homologous structures.

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3
Q

Why is fossilization extremely rare ? ( 2 diff )

A

Fossilisation is an extremely rare chance event. Predator scavengers and bacterial action normally break down dead plants and animals structures before they can be fossilised. After I delete you fossils formed most remain parrot or if they do become exposed are overlooked or accidentally destroyed

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4
Q

What is speciation

A

Speciation is a process within evolution that leads to the formation of new, distinct species that are reproductively isolated from one another.

The formation of new and distinct species in the course of evolution. the populations become extremely varied and successful interbreeding cannot happen anymore

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5
Q

What is a species

A

A species is a group of organisms able to interbreed and produce fertile offspring.

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6
Q

Speciation because of isolation ( 4 )

A
  • two populations of a species can become geographically separated because of the environment ( barriers like a river separates population and isolates gene pools of two populations so they can no longer exchange genes )
    -isolation can prevent interbreeding and the combination of genes within a species ( tehy become reproductively isolated )
    -different mutations can take place in the isolated groups and create different phenotypes within a particular location ( adaptive genes are selected and otehrs lost depending on the unique environment of each population )
    -over time species may evolve to be different to each other, and they will not be able to interbreed
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7
Q

What causes speciation

A

Isolation combined with natural selection

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8
Q

Hey does teh number of chromosomes need to halve in gametes

A

So taht teh original chromosome number is maintained in body cells

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9
Q

How does mitosis lead to variation in offspring ( 3 )

A
  • random assortment of parental chromosomes
  • crossing over
  • any sperm can fertilize any egg
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10
Q

What is crossing over ( for variation )

A

Genetic material ( alleles ) from one chromosome is exchanged for those of its pair

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11
Q

Super bugs ( 5)

A

Bacteria mutate very quickly. When a group of bacteria including genetically resistant ones are exposed to an antibiotic ( some bacteria mutate and become resistant to the antibiotics ), most of the normal bacteria die, teh genetically resistant bacteria survive and start multiplying , eventually the resistant strain replace the strain effected by the antibiotic. This creates resistant bacteria that cannot be treated by antibiotics.

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12
Q

Mutations lead to natural selection ( 4 )

A
  1. Mutation creates variation
  2. Unfavorable mutations selected against ( die )
  3. Favorable mutations more likely to survive and reproduce
  4. Creates offspring with favourable mutation
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13
Q

What is a codon

A

set of 3 nucleotides in row along mRNA that matches an anticodon on a tRNA molecule, which carries a specific amino acid.

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14
Q

Homologous features

A

Homologous features are ones that have a common origin and similar anatomy but can carry out different functions e.g. bat wing and human arm

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15
Q

Analogous features

A

Analogous features are features that have similar functions but their origin and anatomy are different e.g. bat wing and insect wing, dolphin flipper and dogfish fing

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16
Q

Selective breeding

A

An artificial process in which organisms with desired characteristics are chosen as parents and bred by humans for the next generation.

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17
Q

Artificial vs natural selection

A

Artificial selection is where humans select for desirable traits in agricultural products or animals, rather than leaving the species to evolve and change gradually without human interference, like in natural selection.

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18
Q

Domestication

A

Domestication is the act of separating a small group of organisms (wolves, in this case) from the main population, and select for their desired traits through breeding

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19
Q

How did dogs evolve

A

Over thousands of years, the domestication of wolves resulted in the loss of some of the more aggressive traits, like the instinctual, defensive behavior in the presence of humans (barking or howling, bearing their teeth, poising to attack, or running away), and the size and shape of their teeth.

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20
Q

What are mutations

A

Random change in a gene or chromosome

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21
Q

What rae the three types of mutations

A

Insertion, substitution and deletion

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22
Q

What are teh two main “levels” of mutations

A

Gene mutations and chromosome mutauisn

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23
Q

Three processes when mutations can happen

A

DNA replication, meiosis, mitosis

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24
Q

Theory of evolution by natural selection - 5 points

A

+ Individualswithinpopulationsaredifferent(havegeneticvariation).
+ Somedifferencesbetweenindividualsarecanbepassedtooffspring.
+ Moreoffspringareproducedthansurviveandreproduce.Somedie.
+ Individualswith“good”differencessurviveandreproduce.Individuals with “bad” differences do not survive and reproduce.
+ Overlongperiodsoftime,thesurvivalandreproductionofonlythe best traits leads to change.
+ “survivalofthefittest”

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25
Variation
Differences between individuals in a species
26
Examples of some factors that show environmental variation
scars language and accent flower colour in hydrangeas as these plants produce blue flowers in acidic soil and pink flowers in alkaline soil
27
Example where environment factors impacts genetics ( features that vary because of a combination of genetic and environmental cUses )
Some features vary because of a combination of genetic and environmental causes. For example, tall parents will pass genes to their children for height. Their children have the genetic potential to also be tall. However, if their diet is poor then they will not grow very well: their environment also has an impact on their height.
28
Genotype
The alleles that an organism has for a particular characteristic
29
Mutation
A random and spontaneous change in the structure of a gene, chromosome or number of chromosomes. Change in the gene or chromosome
30
How do mutations lead to evolution/change
For example, if a mutation leads to a change, such as feather colouring in birds, this new change may allow those individuals to reproduce more frequently, due to them being more attractive and seen as a more desirable mate. This would result in this phenotype being passed on more successfully than the birds of the same species without the new phenotype.
31
Natural selection
Natural selection is a process where organisms that are better adapted to an environment will survive and have more offspring. This means their genes are passed on to the future generations. This process is fundamental to the process of evolution.
32
One risk of selective breeding
Because of selective breeding, future generations of selectively bred plants and animals will all share very similar genes which will reduce variation. Inbreeding can lead to a reduced gene pool, making it more difficult to produce new varieties in the future. This also makes organisms prone to certain diseases or inherited defects.
33
Gene pool
Genes and their different alleles within a population are known as its gene pool.
34
Benefits of selective beeeding - 3
reduced genetic variation can lead to attack by specific insects or disease, which could be extremely destructive rare disease genes can be unknowingly selected as part of a positive trait, leading to problems with specific organisms, eg a high percentage of Dalmatian dogs are deaf can create physical problems in specific organisms, eg large dogs can have faulty hips due to not being formed correctly
35
Molecular evidence for evolution ( 6 )
All organisms share a number of molecular characteristics, which suggest a shared origin of all life on Earth. • All have DNA or RNA as their genetic material. • The genetic code is universal. • ATP is the universal molecule for energy storage. • The proteins in all organisms are formed from the same 20 amino acids. • All have phospholipid membranes. • Vital physiological processes follow very similar metabolic pathways in all organisms.
36
Who decides which members of a polutaion will breed in artificial selection ? ( how does it work and why is it done ?)
In artificial selection humans decide which members of a population will breed. This allows the alleles for desirable characteristics to be maintained in the population and others eliminated. This technique is used by farmers to produce animals and plants with a high yield.
37
Transcription
Copying of a gene ( a section of DNA ) to make mRNA. First step in protein synthesis
38
The five different types of speciation
Allopatric Symptaric Artificial Parapatric Peripatetic
39
New species can arise as a result of ?
Genetic variation Natural selection Speciation Isolation
40
Speciation is a result of ?
isolation mutation selection
41
Allopatric speciation
Allopatric speciation is when new species arise due to isolation of a population by geographical barriers.
42
Peripatetic speciation
When small groups of individuals break off from the larger group and form a new species, this is called peripatric speciation ( key idfffernce form Allopatric is that teh group is much smaller than teh main group)
43
Perapatric speciation
In parapatric speciation (3), a species is spread out over a large geographic area. Although it is possible for any member of the species to mate with another member, individuals only mate with those in their own geographic region. Like allopatric and peripatric speciation, different habitats influence the development of different species in parapatric speciation. Instead of being separated by a physical barrier, the species are separated by differences in the same environment.
44
Sympatric speciation
In sympatric speciation, groups from the same ancestral population evolve into separate species without any geographical separation. Sympatric speciation occurs when there are no physical barriers preventing any members of a species from mating with another, and all members are in close proximity to one another. A new species, perhaps based on a different food source or characteristic, seems to develop spontaneously.
45
Sympatric speciation may ic ur due to ( according to bbc bitiseize )
Ecological barriers and behavioral barriers ( different more complex mating rituals etc )
46
Three types of adaptations
structural ( physical features ), behavioural ( behaviors) physiological ( process likempoison etc )
47
order of events in the process of speciation?
Isolation, mutation, selection
48
Two types of gene transfer ( which is quicker and what organism use it ? )
Vertical and horizontal gene transfer ( horizontal is faster ). Prokaryotes such as bacteria can exchange genetic information through horizontal gene transfer. This method of gene transfer is instantaneous
49
Vertical gene transfer
when genes are transferred down generations, ie from parent to offspring as a result of sexual or asexual reproduction
50
Horizontal gene transfer
when genes are transferred across from an individual to others in the same generation. This does not occur due to reproduction.
51
What type of gene transfer helps bacteria become resistant
Resistance to antibiotics has spread widely in the bacterial population due to the horizontal transfer of plasmids that carry these resistance genes.
52
Directional selection
In directional selection one extreme of the phenotype range is selected for, in this case dark moths over lighter ones.
53
Disruptive selection
This is when two or more extreme phenotypes are selected for. For example, if there is an area with dark trees covered in areas of light lichen, natural selection will favour two types of moth - those with lots of melanin, which will camouflage against the dark trees, but also the type with very little melanin, which will camouflage against the light coloured lichen.
54
Stabilizing selection
In stabilising selection an average phenotype is selected for and extremes of the phenotype are selected against.
55
How is a gene expressed ?
As a protein
56
Transcription ( short )
DNA to mRNA
57
Translation ( short )
mRNA to protein synthesis
58
During transcription what does Adenine pair with ?
Uracil
59
Only when can natural selection work ?
Natural selection can only act in mutation if they change the phenotype
60
Order of hierarchy
Domain, kingdom, phylum, class, order, family, genus, species Dumb king Philip came over from great Spain
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Mutation levels
DNA level mRNA level Protein level
62
Postzygotic barriers
Prevent hybrids from developing onto healthy, fertile adults ( they’re never fertile sometimes tehy can be healthy )
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Prezygotic barriers
Prevent members of a species form mating to produce a zygote ( different reproduction times - temporal isolation, different mating behaviors - behavior,a isolation, reproductive organs that don’t fit together - mechanical isolation)
64
Morphological species concept
Defines species based on appearance ( could be useful for asexual organisms )
65
What happens to chromosomes during non disjunction
Chromosomes don’t separate as tehy should and are stuck together ( move to one side of teh cell together ). Causes monotony and trisomy
66
Job of tRNA
Bring amino acids to teh ribosome in Teh correct order
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Genome
Complete set of genes present in a cell
68
Three differences between DNA and RNA
Like DNA, RNA nucleotides contain the nitrogenous bases adenine (A), guanine (G) and cytosine (C) Unlike DNA, RNA nucleotides never contain the nitrogenous base thymine (T) – in place of this they contain the nitrogenous base uracil (U) ( remeber this when coding for mRNA) Unlike DNA, RNA nucleotides contain the pentose sugar ribose (instead of deoxyribose) Unlike DNA, RNA molecules are only made up of one polynucleotide strand (they are single-stranded)
69
Gene
A gene is a sequence of nucleotide bases in a DNA molecule that codes for the production of a specific sequence of amino acids, that in turn make up a specific polypeptide (protein)
70
This process of protein synthesis occurs in two stages:
Transcription – DNA is transcribed and an mRNA molecule is produced Translation – mRNA (messenger RNA) is translated and an amino acid sequence is produced
Bio Grade 10
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