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Bio Grade 10 > Lesson 7 > Flashcards

Lesson 7 Flashcards

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Biology 101 flashcards
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
Q

Variation

A

Differences between individuals in a species

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26
Q

Examples of some factors that show environmental variation

A

scars
language and accent
flower colour in hydrangeas as these plants produce blue flowers in acidic soil and pink flowers in alkaline soil

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27
Q

Example where environment factors impacts genetics ( features that vary because of a combination of genetic and environmental cUses )

A

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.

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28
Q

Genotype

A

The alleles that an organism has for a particular characteristic

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29
Q

Mutation

A

A random and spontaneous change in the structure of a gene, chromosome or number of chromosomes.

Change in the gene or chromosome

30
Q

How do mutations lead to evolution/change

A

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
Q

Natural selection

A

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
Q

One risk of selective breeding

A

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
Q

Gene pool

A

Genes and their different alleles within a population are known as its gene pool.

34
Q

Benefits of selective beeeding - 3

A

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
Q

Molecular evidence for evolution ( 6 )

A

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
Q

Who decides which members of a polutaion will breed in artificial selection ? ( how does it work and why is it done ?)

A

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
Q

Transcription

A

Copying of a gene ( a section of DNA ) to make mRNA. First step in protein synthesis

38
Q

The five different types of speciation

A

Allopatric
Symptaric
Artificial
Parapatric
Peripatetic

39
Q

New species can arise as a result of ?

A

Genetic variation
Natural selection
Speciation
Isolation

40
Q

Speciation is a result of ?

A

isolation
mutation
selection

41
Q

Allopatric speciation

A

Allopatric speciation is when new species arise due to isolation of a population by geographical barriers.

42
Q

Peripatetic speciation

A

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
Q

Perapatric speciation

A

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
Q

Sympatric speciation

A

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
Q

Sympatric speciation may ic ur due to ( according to bbc bitiseize )

A

Ecological barriers and behavioral barriers ( different more complex mating rituals etc )

46
Q

Three types of adaptations

A

structural ( physical features ), behavioural ( behaviors) physiological ( process likempoison etc )

47
Q

order of events in the process of speciation?

A

Isolation, mutation, selection

48
Q

Two types of gene transfer ( which is quicker and what organism use it ? )

A

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
Q

Vertical gene transfer

A

when genes are transferred down generations, ie from parent to offspring as a result of sexual or asexual reproduction

50
Q

Horizontal gene transfer

A

when genes are transferred across from an individual to others in the same generation. This does not occur due to reproduction.

51
Q

What type of gene transfer helps bacteria become resistant

A

Resistance to antibiotics has spread widely in the bacterial population due to the horizontal transfer of plasmids that carry these resistance genes.

52
Q

Directional selection

A

In directional selection one extreme of the phenotype range is selected for, in this case dark moths over lighter ones.

53
Q

Disruptive selection

A

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
Q

Stabilizing selection

A

In stabilising selection an average phenotype is selected for and extremes of the phenotype are selected against.

55
Q

How is a gene expressed ?

A

As a protein

56
Q

Transcription ( short )

A

DNA to mRNA

57
Q

Translation ( short )

A

mRNA to protein synthesis

58
Q

During transcription what does Adenine pair with ?

A

Uracil

59
Q

Only when can natural selection work ?

A

Natural selection can only act in mutation if they change the phenotype

60
Q

Order of hierarchy

A

Domain, kingdom, phylum, class, order, family, genus, species

Dumb king Philip came over from great Spain

61
Q

Mutation levels

A

DNA level
mRNA level
Protein level

62
Q

Postzygotic barriers

A

Prevent hybrids from developing onto healthy, fertile adults ( they’re never fertile sometimes tehy can be healthy )

63
Q

Prezygotic barriers

A

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
Q

Morphological species concept

A

Defines species based on appearance ( could be useful for asexual organisms )

65
Q

What happens to chromosomes during non disjunction

A

Chromosomes don’t separate as tehy should and are stuck together ( move to one side of teh cell together ). Causes monotony and trisomy

66
Q

Job of tRNA

A

Bring amino acids to teh ribosome in Teh correct order

67
Q

Genome

A

Complete set of genes present in a cell

68
Q

Three differences between DNA and RNA

A

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
Q

Gene

A

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
Q

This process of protein synthesis occurs in two stages:

A

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 (5 decks)

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