Evolutionary Origins of Biodiversity Flashcards

0
Q

What is another word for heritable factor?

What is the ratio of dominant characteristics to recessive?

A

Gene

3:1

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1
Q

What were the two alternate models of inheritance?

A

Blending and particulate

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2
Q

What is Mendel’s first law of segregation?

A

1) Alternate versions of heritable factors account for variations in inherited characters
2) For each character an organism inherits two copies of each heritable factor. 1 from each parent.
3) If the two versions differ the dominant version determines appearance.
4) The two copies of a heritable factor separate in the formation of gametes.

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3
Q

What is Mendel’s second law of independent assortment?

A

When two characters are observed together characters behave as independent units

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4
Q

What are the types of mutation? Give examples.

A

Silent - no impact on phenotype (e.g. mutation to 3rd base or junk DNA)

Small effect - change to a similar amino acid, change in non crucial part of protein.

Big effect - change to very different AA. Change to key region of protein (e.g. active site). Nonsense mutation. Frameshift mutation. Large deletion. Change to regulatory region.

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5
Q

What is pleiotropy?

What is epistasis?

A

Where 1 gene affects several phenotypic characteristics.

Where two genetic loci impact phenotype.

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6
Q

What are the three types of selection?

A

Stabilising - reduced variation

Directional - common when environment changes

Disruptive - intermediates disadvantaged

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7
Q

What are three mechanisms of evolutionary change?

A

Genetic drift - random change

Gene flow - movement of alleles between populations

Natural selection - select organisms best adapted to survive

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8
Q

What is microevolution?

What is macroevolution?

A

Evolution of populations or single species

Grand evolutionary trends e.g. Land plants from algae

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9
Q

What are some of the mechanisms of macroevolution?

A

Stasis - little change, well adapted

Exaptation - adaption of existing structures to new purposes

Mass extinction

Adaptive radiation - 1 line rapidly diverges to fill ecological niches. Can exploit habitat in new ways

Coevolution - two species evolve together

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10
Q

What is phylogeny?

What is a clade?

A

Reconstruction of evolutionary relationships

A group sharing one or more defining derived traits

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11
Q

What is a eukaryote?

What is a embryophyte?

What is a tracheophyte?

What is a spermatophyte?

What is a angiosperm?

What is a gymnosperm?

A

Organism with a nucleus

Land plant

Vascular plant

Seed plant

Flowering Plants

Conifers and their allies

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12
Q

What are derived traits?

What are shared derived traits called?

Where does a sporophyte develop?

A

Traits not present in primitive times

Synapomorphiles

Where gametes fuse

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13
Q

What is a gametangia?

What is a male gametangia?

What is a female gametangia?

A

Organism that produces gametes

Antheridia

Archegonia

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14
Q

What is a closed circulatory system?

What is an open circulatory system?

A

Like ours, blood vessels are connected to the heart and return to the heart

Blood vessels go from heart and end at a dead end, blood is returned to the heart by other methods.

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15
Q

What is a meristem?

A

A part of a plant which divides rapidly and enables growth.

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16
Q

What is a synapomorphie?

A

A shared evolutionary trait

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17
Q

What is the IPNI?

What is a taxon?

A

International plant names index

A named entry in any rank

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18
Q

What are some of the characteristics of fungi?

A

All are absorbative heterotrophs,
have a cell wall made of chitin,
often have asexual and sexual lifecycles,
have a diverse organisation e.g. some have hyphae and some are single celled

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19
Q

What are hyphae usually for?

What are rhizoids?

A

Absorption

Hyphae used for anchoring

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20
Q

What are the major fungal clades?

A

Microsporidia - intracellular parasites

Chytrids - ancient group, aquatic in nature

Zygomycota - moulds, important decomposers

Glomeromycota - form mutualistic relationship with plants

Ascomycota - sac fungi, includes yeasts

Basidiomycota - club fungi, important decomposers

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21
Q

What is the ectoderm?

What is the endoderm?

What is the mesoderm?

A

The outer layer of an organism e.g. Skin

The innermost layer of an organism, the gut and some organs

Layer between muscle and most other organs

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22
Q

What is a coelomate?

What is a pseudocoelomate?

What is a acoelomate?

A

Has a body cavity surrounded by a mesoderm, the gut and organs are suspended

Has a cavity surrounded by a mesoderm, but no muscle surrounds the digestive system

Has no body cavity

23
Q

In animals what is gastrulation?

What is protosome development?

What is deuterostome?

A

Occurs during development, the folding inwards of the membrane, leads to beginning of layers

Occurs mostly in worms, molluscs etc… During gastrulation the gastropore (point that folds in) develops into the mouth (basically mouth develops first)

When folding in occurs gastropore forms anus, mouth formed second, occurs in higher animals such as chordates

24
Q

What clade contains animals?

A

Metazoan clade

25
Q

What is the ecdysozoan clade?

What groups does it contain?

A

The most species rich clade, name comes from toughened exoskeleton, grow by moulting

Two most important phyla:
- Nematoda: non segmented worms, no circulatory system

  • Arthropoda: have hardened exoskeleton which prevents desiccation, subphyla: chelicerates, myriapoda, Hexapoda, and Crustacea
26
Q

What is a population?

What is a gene pool?

What is allele frequency?

A

A group of individuals of the same species that live in a area and interbreed

All copies of every allele at every locus

Proportion of each allele present in a population, used to see if a population is evolving

27
Q

How do chemo-autotrophs obtain energy?

A

By oxidising inorganic compounds e.g. methane, hydrogen, ammonium….

28
Q

What are some types of archaea?

A

Halophiles - live in salty environments

Acidophiles - found in acidic environments e.g. coal spoilage heaps, acid mine drainage…

Methanogens - found in anaerobic environments e.g. the gut of animals, swamps, landfill sites… Produce methane

29
Q

How old is the Earth?

How long ago was cellular life thought to emerge?

A

~4.54 billion years old

~3.5 billion years ago

30
Q

What are some of the common features of protisits?

A

All have a nucleus,
have a cytoskeleton,
most/ all have mitochondria,
can be autotrophs, heterotrophs or mixotrophs, can be single celled or multicellular e.g. seaweed.

31
Q

Protists are polyphyletic, what does this mean?

A

Have ancestors of very different evolutionary origins

32
Q

What are the five proposed clades for the eukarya group?

A

Excavata - named for modified cytoskeleton

Rhizaria - diverse amoeba like

Chromaleolata - large diverse group, divided into two sub groups alveolates and stramenopiles, contains the apicomplexans which malaria is one of

Archaeplastida - contains red algae, green algae and land plants

Unikonta - large and diverse, two sub groups amoebozoans and opisthokonts (contains fungi and animals)

33
Q

Describe the life cycle of malaria.

A
  1. A female Anopheles mosquito carrying malaria-causing parasites feeds on a human and injects the parasites in the form of sporozoites into the bloodstream. The sporozoites travel to the liver and invade liver cells.
  2. Over 5-16 days, the sporozoites grow, divide, and produce tens of thousands of haploid forms, called merozoites, per liver cell.
  3. The merozoites exit the liver cells and re-enter the bloodstream, beginning a cycle of invasion of red blood cells, asexual replication, and release of newly formed merozoites from the red blood cells repeatedly over 1-3 days. This multiplication can result in thousands of parasite-infected cells in the host bloodstream, leading to illness and complications of malaria that can last for months if not treated.
  4. Some of the merozoite-infected blood cells leave the cycle of asexual multiplication. Instead of replicating, the merozoites in these cells develop into sexual forms of the parasite, called male and female gametocytes, that circulate in the bloodstream.
  5. When a mosquito bites an infected human, it ingests the gametocytes. In the mosquito gut, the infected human blood cells burst, releasing the gametocytes, which develop further into mature sex cells called gametes. Male and female gametes fuse to form diploid zygotes, which develop into actively moving ookinetes that burrow into the mosquito midgut wall and form oocysts.
  6. Growth and division of each oocyst produces thousands of active haploid forms called sporozoites. After 8-15 days*, the oocyst bursts, releasing sporozoites into the body cavity of the mosquito, from which they travel to and invade the mosquito salivary glands. The cycle of human infection re-starts when the mosquito takes a blood meal, injecting the sporozoites from its salivary glands into the human bloodstream .
34
Q

Why in prehistoric times was it evolutionary beneficial for ancient water plants to colonise the land?

What were some of the challenges of plants evolving onto land?

A

There is bright sunlight unfiltered by water and plankton
More CO2
Soil rich in minerals
Initially there were few herbivores and pathogens on land
Unoccupied niche in which to evolve (adaptive radiation)

Relatively less water
Less protection from UV
Lack of structural support

35
Q

What are some of the derived traits of land plants?

A

Alternation of generations
Multicellular dependent embryos
Walled spores produce sporangia
Multicellular gametangia (organism that produces gametes)
Apical meristems (part of the plant which divides and grows rapidly)

36
Q

Who created the binomial naming system where species are named after their genus and species?

A

Carl Linnaeus

37
Q

If a scientist discovers a species they can give it a name, what are some of the reasons the name may have to be changed?

A

Illegitimate names - not avalid description/ descrition not in Latin
Poorly typified names - uncertain application, loss of type specimin
Change of rank - e.g. species to subspecies or vise versa

38
Q

What group contains fungi?

A

Unikonta

39
Q

What is a lichen composed of?

What do these components gain from this relationship?

What are the three lichen forms?

A

A sac fungi and a photosynthetic microbe

Fungus gains AA, sugars etc…
Microbe gains protection

Crustose (crusty), foliose (leafy), and fruiticose (branching)

40
Q

What is radial symmetry?

What is bilateral symmetry?

A

Top and bottom are different but cross section in radial plane is symmetrical e.g. anemones

Top/ bottom and front/ back are different but left and right are symmetrical

41
Q

What is the name of the group in the deuterostomia that are invertebrates?

What type of animal is found in this group?

What is the other group type under deuterostomia?

A

Echinoderms

Starfish and other spiny skins

Chordates

42
Q

What can we learn about development from basal chordates?

A

We can learn about brain development from lancelets, lancelets don’t have a brain but have a swollen tip at the end of their dorsal nerve cord which suggests a precursor to the brain.
They also have the same Hox gene expression that controls vertebrate brain development

Tunicates can tell us about the origins of organs. They don’t have organs themselves but possess genes involved in heart differentiation

43
Q

What are the groups of the deuterostomia?

A

Echinoderms - invertebrates

Chordates - deterostomes with a notochord

Craniates - chordates with a head

Vertebrates - craniates with backbone

Gnathostomes - vertebrates with jaws

Tetrapods - gnathostomes with limbs

44
Q

What is allopatric speciation?

A

Speciation that occurs when organisms become geographically isolated from each other

45
Q

What type of organism is it though the nucleus evolved from/ in?

What type of organism is it though mitochondria evolved from?

What type of organism is it though chloroplasts evolved in?

A

An archea

Bacteria (purple bacteria group)

Cyanobacteria

46
Q

What are coenocytial hyphae?

What are septate hyphae?

A

Hyphae where cells aren’t separate, cytokinesis hasn’t occurred after mitosis

Cells are separated off but cytokinesis is not complete and the is a hole in the middle of the wall separating cells

47
Q

What is a heterokayrotic state and what organisms can exist in this state?

A

Where there are two haploid nuclei that have not fused (n + n). Fungi can exist in this state

48
Q

What is supposed to be the closest relatives to multicellular life?

Give a brief explanation of how it’s thought multicellular life evolved.

A

Choanoflagellates (a protist)

Some choanoflagellates are colonial and stick together using adhesion proteins. It’s thought adhesion proteins were originally used to catch prey and evolved a new role in cell adhesion

49
Q

What is meant by polygenic inheritance? Give an example.

What is mean by the term multifactorial trait? Give one example and explain it.

A

Not all alleles have distinct alternate forms like Mendel found. Some vary greatly and this variation is caused by many different alleles e.g. Skin colour is caused by many genes.

Phenotypic characteristics which can also be affected by the environment. E.g. Hydrangeas can vary in colour despite being genetically identical. In London they have pink flowers whereas in Cornwall they have blue flowers. This difference is due to soil content.

50
Q

What does plasmogamy mean?

What is karyogamy?

What is a heterokaeyon?

What is a dikaryon?

What is a mating type?

A

Cytoplasmic fusion

Nuclear fusion

Two genetically distinct nuclei

Has two nuclei but they have not fused

A strain of species only capable of sexual reproduction with other strains of the species

51
Q

What are the three lineages of mammals?

A

Monotremes, marsupials and eutherians

52
Q

What characteristics define an animal?

A

All multicellular - have life-cycles with complex patterns of development

All heterotrophic

Most animals digest food internally

Most animals have some form of motility

53
Q

What groups make up the lophotrochozoa?

A

Platyhelminthes - flattened worms

Rotifers - tiny marine animals

Brachiopods - marine animals with two part shell

Annelida - segmented worms

Molluscs - shelled organisms

54
Q

Describe the morphology of two of the phyla of lophotrochozoa. Give examples of species within each.

A

Platyhelminthes - flattened, triploblastic, no gas exchange organs, include tapeworms and flukes.

Annelids - live in marine, freshwater and damp environments, bilateral symmetry, gas exchange through skin, segmented: heart in each segment, include earthworms and leeches