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Bio Grade 12 Semester 1 > Biodiversity and Evolution > Flashcards

Biodiversity and Evolution Flashcards

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1
Q

What are the 8 taxonomic classifications? (Dear King Phillip Came Over For Good Sushi)

A
  • Domain
  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
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2
Q

When might reclassification might be necessary?

A

New evidence indicates that members of a taxa do or don’t share a common ancestor when it was previously thought otherwise.

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3
Q

Explain the reclassification of birds.

A
  • Birds were classified as Aves
  • But it it now understood that they share a more recent ancestor with some modern reptiles (crocodiles) than with others (snakes).
  • Natural classification now places birds in the same taxa as crocodiles (theropoda)
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4
Q

Classify a plant from domain to species (I’m doing ackee!)

A

Domain: Eukaryota
Kingdom: Plantae
Phylum: Angiospermatophyta
Class: Eudicots
Order: Sapindales
Family: Sapindaceae
Genus: Blighia
Species: sapida

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5
Q

Classify an animal from domain to species.

A

Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Apodiformes
Family: Trochilidae
Genus: Trochilus
Species: polytmus

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6
Q

What are the different types of natural classifications?

A
  • Physical (appearance)
  • Behavioural
  • Physiological (how cell systems work)
  • Biochemical (chemical make-up of the organisms)
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7
Q

What is phylogenetic classification?

A

It’s a classification used to differentiate organisms based on genetics / evolutionary history

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8
Q

Name the three domains and the six kingdoms.

A

Three domains:
- Eu-bacteria
- Archae-bacteria
- Eukarya

Six kingdoms:
- Eu-bacteria
- Archae-bacteria
- Protista
- Plantae
- Fungi
- Animalia

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9
Q

Name one problem with natural classification.

A
  • Species are physically and genetically diverse with constantly changing attributes.
  • Convergent evolution causes distantly related organisms to appear superficially similar.
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10
Q

What evidence supports the three domain classification?

A

Genetic sequencing–each of the domains contain unique rRNA

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11
Q

Which diverges from the other two first? Bacteria, archaea, or eubacteria?

A

Bacteria.

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12
Q

List four differences between archaea and eubacteria.

A

Can name any of these 7.

Archaea: have histone proteins
Eubacteria: do not have histone proteins

Archaea: Usually have intron DNA sequences
Eubacteria: Usually do not have intron DNA sequences

Archaea: Cell walls not made of peptidoglycan
Eubacteria: Cell walls made of peptidoglycan

Archaea: Membrane phospholipids can be branched
Eubacteria: Membrane phospholipids can’t be branched

Archaea: Not sensitive to antibiotics that affect eubacteria.
Eubacteria: Sensitive to antibiotics that do not affect archaea

Archaea: Different ribosomes than eubacteria
Eubacteria: Different ribosomes than archaea

Archaea: Can live in extreme environments
Eubacteria: Most do not live in extreme environments

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13
Q

What are the traditional characteristics of life?

A

Homeostasis, reproduction, metabolism, excretion, nutrition, growth, stimulus

Mnemonic: (HR MENG’S)

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14
Q

Why are viruses considered non-living?

A

They need a host in order to reproduce and they cannot metabolize.

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15
Q

What are the three types of diversity?

A

Genetic, species, ecological

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16
Q

What are the characteristics of an animal?

A
  • Heterotrophs (eat other organisms for energy)
  • Exposed (no cell wall)
  • Internal digestion
  • Multicellular eukaryotes
  • Sexual reproduction
  • Movement
  • Organs (sensory organs)

Mnemonic: Hey Evil Iron Man, suck me off!

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17
Q

What are the seven phyla you need to know for IB Bio? Give one example of each.

A
  • Porifera
  • Cnidaria
  • Platyhelminthes
  • Mollusca
  • Annelida
  • Arthropoda
  • Chordata

Mnemonic: Pack cipralex, prozac, meth, alcohol, and crack!

Examples:
- Sea sponge
- Jellyfish, coral, sea anemone, or hydra
- Tapeworm, planaria
- Snail, octopus, clam, squid
- Earthworm, leech
- Insects, spiders, crustaceans
- Bird, fish, turtle

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18
Q

What is the difference between radial symmetry and bilateral symmetry?

A

Simple

Radial symmetry is symmetrical around a central axis, bilateral is two mirror image halves

ETC

Radial:
- Identical body halves around a central axis
- Top and bottom surfaces; no left and right, no front and back
- Suited for stationary / random motion lifestyles

Bilateral:
- Division of an animal through a sagittal (splits into left and right) plane
- Two mirror image halves
- Head and tail, front and back, right and left
- Streamlined and directional motion

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19
Q

What phylum lacks true tissue and is asymmetrical?

A

Porifera

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20
Q

Explain how porifera obtain food

A
  • Cells with flagella that capture bacteria and tiny food particles (no mouth or anus)
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21
Q

Which phylum has radial symmetry?

A

Cnidaria

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22
Q

How do cnidaria obtain food?

A

Using tentacles with stinging cells called nematocysts

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23
Q

Name the five phyla that have bilateral symmetry. What do they have in common?

A
  • Platyhelminthes
  • Mollusca
  • Annelida
  • Arthropoda
  • Chordata

They can all live in marine, terrestrial, and freshwater habitats.

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24
Q

Name at least two distinct features of each of the five phyla with bilateral symmetry.

A

Platyhelminthes (flatworms):
- Flattened, unsegmented body
- Mouth but no anus
- Typically hermaphrodites
- Oxygen diffused directly into body

Annelida (earthworms):
- Segmented worms
- Move via peristalsis
- Oxygen diffused directly into body

Mollusca:
- Three main body parts (muscular foot, visceral mass, mantle)
- May have hard calcium carbonate shell
- Gas exchange via gills

Arthropoda:
- Segmented body
- Jointed appendages
- Tough exoskeleton made of chitin
- Body consists of head, thorax, abdomen
- Gas exchange through surface, trachea, gills, or lungs

Chordata
- Dorsal, hollow nerve cord
- Gas exchange through skin, gills, or lungs

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25
Q

Define the four defining anatomical features of phylum chordata animals.

A
  • Notochord: a stiff rod of cartilage extending along inside the body –> develops into a spine
  • Dorsal nerve cord –> develops into spinal cord
  • Pharyngeal slits –> openings in pharynx extending to outside environment
  • Post-anal tail –> muscular tail extending backwards behind the anus
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26
Q

What are the three subphyla of phylum chordata?

A
  • Subphylum urochordata
  • Subphylum cephalochordata
  • Subphylum vertebrata
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27
Q

What are the five classes of vertebrates that need to be remembered for IB?

A
  • Amphibia
  • Mammalia
  • Osteichthyes
  • Reptilia
  • Aves

Mnemonic: AMORA

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28
Q

What are the skin characteristics of amphibians and reptiles?

A

Amphibia:
- Permeable so liquids/gasses can pass through
Reptilia:
- Thick, scaly skin that sheds

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29
Q

Which vertebrates perform endothermic regulation?

A

Birds and mammals

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30
Q

Which vertebrates perform external fertilization?

A

Osteichthyes and amphibians (amphibians also perform internal fertilization)

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31
Q

What method of gas exchange do each of the five vertebrae perform?

A

Osteichthyes:
- O2 dissolved in water through gills
Amphibia:
- Conducted through skin, gills, and lungs
Reptilia, aves, and mammalia:
- Through lungs

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32
Q

Which of the five vertebrates reproduce with amniotic eggs?

A

Reptiles (leathery shell) and aves (calcium carbonate shell)

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33
Q

How do reptiles increase lung surface area vs mammals?

A
  • Reptiles have many folds in their lungs in order to increase surface area.
  • Mammals have a branching system with several tubes, leading to alveoli.
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34
Q

What are some key features of plants?

A
  • They are autotrophs (produce their own food through photosynthesis
  • They are eukaryotic
  • They have cell walls made of cellulose
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35
Q

Name the four phyla of the plant kingdom, and which of these four do not contain vascular tissue? Give an example of each

A
  • Bryophytes (mosses) –> peat moss
  • Filicinophytes (ferns) –> ostrich fern
  • Coniferophytes (conifers) –> cedar
  • Angiospermophytes (flowering plants) –> orchids

Bryophytes do not possess vascular tissue.

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36
Q

What are the three requirements of a vascular plant?

A
  1. They must have roots, stems, and leaves
  2. They must have vascular tissues to transport substances around the plant
  3. They must have xylem vessels with the stiffening agent lignin to allow them to grow taller than non-vascular.
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37
Q

Detail the two methods of sperm distribution of the phyla, and which two do each

A

Bryophytes and filicinophytes:
–> Sperm cells have flagella and swim through water to reach egg

Coniferophytes and angiospermophytes
–> Pollen grains with sperm-containing cells are dispersed by wind or pollinators

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38
Q

Which of the four plant phyla have seeds and which have spores? In the ones with seeds, what are those seeds covered by respectively?

A

Bryophytes and filicinophytes: spores
Coniferophytes: seeds covered by cones
Angiospermatophytes: seeds covered by fruit

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39
Q

Describe the reproduction process of coniferophytes.

A

Pollen is released from male cones and carried by wind to the female cones. Pollen sticks to ovules and fertilization occurs.

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40
Q

Describe the reproduction process of angiospermophytes

A

Pollen is transferred to the stigma of carpels from anthers, and then ovules found in the ovary are fertilized

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41
Q

Define the diploid and haploid part of a plant.

A

Diploid: part of plant that grows seasonally for reproduction–it produces and releases spores
Haploid: short part of plant with no vascular tissue

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42
Q

What are rhizoids and thallus? Which phylum are they present in?

A

Rhizoids are hair-like projections that replace roots; they grow directly out of photosynthetic tissue

Thallus are flattened, leaf-like structures.

Both are are present in bryophytes.

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43
Q

Describe the leaves of filicinophytes and coniferophytes respectively.

A
  • Pinnate leaves with spores in clusters called sori on the underside.
  • Evergreen, needle-shaped with a waxy cuticle to limit water evaporation.
44
Q

What is a cladogram and what is it based on?

A

A tree diagram that represents the most probably sequence of divergence within a clade (a group that shares characteristics).

It’s based on sequence analysis of DNA bases or amino acids from proteins.

45
Q

What is a node, and what does a greater amount of nodes between species signify?

A

A node is the point where characteristics branch and species diverge. The more nodes between species, the more distant their relationship.

46
Q

What does the y-axis signify on a cladogram?

A

Time.

47
Q

What is different about a phylogenetic tree compared to a cladogram?

A

Phylogenetic trees have lines representative of the amount of time between organisms’ ancestry.

48
Q

Explain the reclassification of the figwort family!

A
  • Scientists compared chloroplast DNA
  • They realized that what was once thought to be one clade was actually five.
  • These clades were impossible to distinguish with morphology due to their similarities (convergent evolution!).
  • The figwort family contains 200 species, the 36th largest family of all angiosperms
49
Q

Describe Lamarckism.

A
  • Each species gradually becomes more complex.
  • Organisms are not passively altered by the environment
  • Organisms acquire traits over their lifetime to adapt to their environment that they pass on to their offspring
50
Q

Describe Darwinism.

A

Centers around “natural selection”
- Some heritable traits better enable organisms to survive/reproduce
- Advantageous traits become more common over generations
- Allele frequencies and gene pools change
- Origin of species, not life.

51
Q

What are the four main factors of natural selection?

A
  1. Struggle for survival: Competition for limited resources, tendency to produce more offspring than can be supported.
  2. Variation: Natural variation within a population/species results in some traits being more advantageous
  3. Changing environment: As environment slowly changes, the traits which are advantageous change
  4. Randomness: Variations are random, and the environment selects those that are best suited. Evolution has no ultimate goal.

(Mnemonic: Shitty Velociraptors Can’t Run!)

52
Q

What are the three main ways that antibiotics kill bacterial cells?

A
  1. (Wall) Prevent them from building a cell wall
  2. Dissolve the membrane of bacterial cells
  3. (Machinery) Affect protein-building or DNA copying machinery specific to bacteria

Mnemonic: We Don’t Matter

53
Q

What are the four steps in the process of antibiotic resistance?

A
  1. Starts with bacteria, including resistant variety
  2. All bathed in antibiotics—most of the normal bacteria die
  3. Resistant bacteria multiply and become more common
  4. Entire infection eventually evolves into a resistant strain
54
Q

What are some mechanisms of antibiotic resistance?

A
  • Modified drug target
  • Efflux pumps
  • Drug inactivating enzyme
  • Modified cell wall protein

Mnemonic: My EDM

55
Q

Name and explain the two modes of evolution.

A

Microevolution
- Change in gene frequency within a population
- Occurs between one generation and the next

Macroevolution
- Large-scaled
- Takes place over a long period of time
- Changes, diversifications, and extinctions that take place over history

Microevolution leads to macroevolution.

56
Q

How can we impede antibiotic resistance?

A
  1. Preventing transmission of bacterial/viral/sexual infections by:
    - Handwashing
    - Avoiding close contact with sick people
    - Using condoms
  2. Getting and remaining vaccinated
  3. Using antimicrobial drugs carefully
    - Make sure they’re prescribed by a certified health professional
    - Don’t use for viral infections
    - Complete full treatment no matter what
    - Never share or use leftover prescription
57
Q

What are the three types of selective pressure?

A
  • Stabilizing selection
  • Directional selection
  • Disruptive selection
58
Q

Explain stabilizing selection and try and describe its corresponding graph.

A
  • Widespread
  • Existing variations that are beneficial are already common.
  • Acts against the extremes of a trait—the more an organism deviates, the less likely it is to survive.

Bell curve becomes thinner.

59
Q

Explain directional selection and try and describe its corresponding graph.

A
  • One extreme of a trait offers a survival/reproductive advantage
  • Increases allele frequencies at one phenotypic extreme, reduces them at the other

Bell curve shifts to the right or left

60
Q

Explain disruptive selection and try and describe its corresponding graph.

A
  • Frequent phenotype becomes disadvantageous
  • Individuals at either extreme have better rates of survival/reproduction.

Bell curve splits in two

61
Q

Name and explain the two types of speciation models. What do their graphs look like?

A

Gradualism
- Slow, constant, consistent
- Hard-to-notice changes over a short period of time
- Small variations that fit an organism for its environment slightly better
- Population changes gradually over a long period of time

Punctuated equilibrium
- Periods of no change followed by one or a few huge changes (often mutations in the genes of a few individuals), and then a return to no change
- Species changes significantly over a short period of time

Gradualism has linear graph, punctuated equilibrium has stair-like, choppy graph.

62
Q

How do fossils form?

A

Organisms become compressed in layers of sediment from rock or sand; soft tissues decompose but harder organic materials form fossils.

63
Q

What are the main things that fossils represent?

A
  • Remains preserved in resins (or other environments) that slow the decay process
  • Mineralized representations of remains
  • Resin imprints of remains
64
Q

Give three examples of both direct and indirect evidence of fossils.

A

Direct evidence:
- Bones
- Teeth
- Shells

Indirect evidence:
- Footprints
- Tooth marks
- Burrows
- Faeces

65
Q

What are the three main limitations of fossil evidence?

A
  • Requires an unusual set of specific circumstances to occur –> very few organisms become fossils
  • Only hard parts typically preserved
  • Limited fossil data makes it difficult to discern evolutionary patterns that result from ancestral forms
66
Q

Explain the law of fossil succession.

A

The relative age of a fossil can be estimated from knowing its position within layers of rock.

Older fossils:
- in deeper layers
- less complex

Newer fossils:
- closer to the surface
- increasingly complex

67
Q

What is thought to be the general trend of the evolution of the animal kingdom?

A

Fish –> amphibian –> reptile –> bird / mammal

68
Q

What are transitional organisms?

A

Organisms that establish links between species by exhibiting traits common to both an ancestor and its predicted descendants.

69
Q

Name 3 primates

A

Can name any of these:

  • Monkey
  • Baboon
  • Orangutan
  • Chimpanzee
  • Gorilla
70
Q

Name any four characteristics of primates.

A

Name any of these.

  • Adapted for an arboreal (tree-dwelling) life in a forest environment
  • Forward facing eyes (binocular vision - stereoscopic)
  • Larger brains (improved cognition)
  • Opposable thumbs (power/precision grip)
  • Finger pads with nails instead of claws (improved tactile sensitivity)
  • Skull adapted for upright posture (downward facing foramen magnum)
  • Rotating hand / forelimb (capable of pronation)
  • Flexible shoulder joints (shoulder blades on dorsal side of thorax)
71
Q

Name four characteristics of primates.

A

Can name any of these 6:

  • (Hands) Grasping hands/feet with opposable first digits (thumbs)
  • (Fingers) Finger pads and fingerprints
  • (Nails) Nails instead of claws
  • (Eyes) Forward facing eyes for depth perception
  • (Shoulders) Limber shoulder joints for mobility
  • (Parents) Extended parental care
72
Q

Classify humans using taxonomic classification.

A

Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primate
Family: Hominid
Genus: Homo
Species: sapiens
(Subspecies: sapiens)

73
Q

What are the two identifiers of hominids and the two main groups?

A
  • Large brain size
  • Bipedalism

Two main groups:
- Genus 1: Australopithicus
- Genus 2: Homo

74
Q

Where are the oldest hominid fossils from?

A

Eastern and Southern Africa.

75
Q

Detail the progression to Homo sapiens sapiens

A

–> Australopithecus
–> Homo habilis
–> Homo sapiens neanderthalensis
–> Homo sapiens sapiens

76
Q

Explain each of the 5 hominid adaptations.

A
  1. Brain size
    - Grew larger throughout evolution
  2. Bipedal posture
    - Foramen magnum under skull
    - Greater power in legs rather than arms
    - Came before larger brain size
    - Caused by environmental changes most likely.
  3. Jaw shape and dentition
    - Humans have shorter, duller canines and short, wide molars
    - Hominid ancestors have longer jaws
  4. Reduced size difference between sexes
  5. Changes in family structure.
    - Increase of monogamy
    - Larger parental care for offspring.
77
Q

Explain convergent evolution, divergent evolution, and coevolution.

A

Convergent evolution:
- Two different species evolve a similar characteristic independently of one another, because they face similar environment challenges / selective pressures.

Divergent evolution:
- One common lineage evolves due to differences in ecological conditions, which leads to the formation of new species. Due to genetic drift and natural selection.

Coevolution:
- Two or more species reciprocally affect each other’s evolution, due to their close ecological interactions.

78
Q

Define analogous structures. Are they created by convergent or divergent evolution?

A

When species have a similar function or external appearance but have a completely different internal organization.

Convergent evolution–evolved from different lineages, but have similar functions due to similar environmental challenges.

79
Q

Define homologous structures. Are they created by convergent or divergent evolution?

A

Different species have similar internal structures that are used for a similar or different purpose.

Divergent evolution–the species are similar internally because they evolved from a common ancestor, but have developed differently, so their structures may be used for different purposes.

80
Q

Define vestigial structures.

A

A similar structure in different species that has reduced or no function in some of the species.

81
Q

Define a species.

A

Members of groups or populations that interbreed or have the ability to interbreed with each other.

82
Q

Define allopatric and sympatric speciation.

A

Allopatric: two populations become geographically separated.
Sympatric: populations split into separate gene pools but continue to share a similar geographic location.

83
Q

Name three different types of reproductive isolation that fit into sympatric speciation.

A
  • Behavioural isolation (eg different courtship)
  • Temporal isolation (flowers that bloom in spring vs summer)
  • Gamete isolation (gametes are not compatible)
84
Q

Explain polyploidy.

A
  • Occurs in cells/organisms when there are more than two homologous sets of chromosomes
  • Nuclei have different number of chromosomes
  • Generates immediate reproductive isolation and sympatric speciation.
85
Q

What are the four things that all living organisms have in common? (Don’t Go To Mars!)

A
  1. DNA (genetic material)
  2. Genetic codes
  3. Transcription and translation (gene expression)
  4. Molecular building blocks eg amino acids
86
Q

How do biologists find out how species are evolutionarily related to each other?

A

Compare sequences of homologous genes, looking for protein and DNA.

87
Q

What does the number of differences in DNA Code and amino acid sequence mean?

A

The more differences, the more distant the common ancestor and the relation.

88
Q

What is the rate of DNA change?

A

1 base per 25 million years.

89
Q

What do scientists use DNA in non-coded regions to determine?

A
  • Non-coding regions free to accumulate mutations
  • Number of variations accumulated helps to determine time of a divergence between organisms.
90
Q

What does a gene pool consist of? What is a genome?

A

All of the genes and their different alleles that are present in an interbreeding population.

All of the genes of an individual organism.

91
Q

Explain a molecular clock.

A

The method used to measure time when evolutionists work with molecular data. It uses changes in DNA sequences of a common gene to discover the rate of mutation and when divergence of a species occurred.

92
Q

Define evolution.

A

The cumulative change in the genetically controlled characteristics of a species.

93
Q

What causes polyploidy?

A

Non-disjunction: the failure of chromosomes to separate

94
Q

How does having too many offspring negatively influence survival rates in a species?

A

Too many offspring overpopulates the area and exceeds the carrying capacity, possibly leading to species extinction.

95
Q

How does having more alleles affect a gene pool? How does the number of each one affect it?

A

More alleles increases genetic variability and leads to a bigger gene pool. The number of each allele does not affect the gene pool size.

96
Q

What are the five factors that can change allele frequency? (Good Guys Not Nasty Men)

A
  1. Genetic drift
    - Chance entirely
  2. Gene flow
    - Sympatric and allopatric speciation
  3. Non-random mating
    - Sexual selection
  4. Natural selection
  5. Mutations
97
Q

What are two reasons behind genetic drift?

A

Founder effect: a few individuals start a new population with a different allele frequency.

Bottleneck effect: a population’s size is rapidly reduced for at least one generation.

98
Q

Explain the Galapagos finches.

A
  • Darwin realized that the birds on Galapagos all had common characteristics
    –> thus a common ancestor
  • Concluded that the original species migrated to the different islands, providing a variety of niches to occupy.
  • Due to food availability and other selective pressures, finches evolved in different ways.
99
Q

Describe mutation and its results

A
  • A change in a DNA sequence
  • Can happen due to copying mistakes, exposure to harmful materials, viral infections
  • Germline mutations can be passed on to next generation
  • Can be beneficial, harmful, or neutral

Results in new variations.

100
Q

Describe crossing over in meiosis and its impacts on genetic variation.

A
  • Exchange of chromosome segments and their alleles between homologous chromosomes (prophase 1)

Meiosis reshuffles the existing genetic variation.

101
Q

Describe independent assortment in meiosis and its impacts on genetic variation.

A
  • Genes for different traits located on different chromosomes –> passed independently from parents to offspring (metaphase 1)

Reshuffles existing genetic variation within a population

102
Q

Describe segregation of alleles in meiosis and its impacts on genetic variation.

A
  • Diploid individual possesses a pair of alleles
  • Segregations of alleles results in each diploid parent passing a random allele down
  • Each gamete contains one allele per gene–haploid.

Reshuffles existing genetic variation in a population.

103
Q

Describe random mating in sexual reproduction and its impacts on genetic variation.

A
  • Any genetically unique sperm can fertilize the genetically unique egg.

Reshuffles existing genetic variation.

104
Q

Describe random fertilization in sexual reproduction and its impacts on genetic variation.

A
  • All individuals are potential partners – no mating restrictions of selection
  • Infinite possibilities of genetic combinations in offspring

Reshuffles the existing genetic variation.

105
Q

Describe gene flow and its impacts on genetic variation.

A
  • Individual moves into a new population and brings its possibly unique alleles with it

New alleles are brought into a population and the genetic variation increases.

Bio Grade 12 Semester 1 (6 decks)

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