Evolution Flashcards
What is Taxonomy?
Classification of biological organisms on the basis of shared characteristics (KPCOFGS)
What is phylogeny?
The evolutionary development and history of a species and the relationships between taxa.
3 reasons why the fossil record is incomplete?
1) low preservation potential
2) small population size
3) inhabit a small geological area
how does an analogous character arise?
convergent evolution
how does a homologous character arise?
similarity due to common ancestry
what are synplesiomorphies?
shared ancestral characters
what are synapomorphies?
shared derived characters
what are Autapomorphies?
character unique to a taxon
what is a monophyletic group?
Contains the latest common ancestor plus all, and only all, of its descendents
what is a paraphyletic group?
remains after one or more parts of a monophyletic group have been removed
what is a polyphyletic group?
A group in which the most recent common ancestor is assigned to some other group and not the group itself
what is the eight kingdom system?
1) bacteria
2) Archaea
3) Archaeozoa
4) Protista
5) chromista
6) Anamalia
7) Plantae
8) fungi
what are the two types of prokaryote?
1) Eubacteria
2) archaebacteria
what conditions do archaebacteria inhabit?
extreme
3 reasons why is it believed that prokaryotes originated before eukaryotes?
1) they appear earlier in the fossil record
2) they are simpler in every aspect
3) there is evidence eukaryotes developed from prokaryotes
Name two similarities between eukaryotes and prokaryotes
1) The method of transmitting information in triplet code in DNA and translating it into proteins through RNA
2) all amino acids are laevo-rotatory and in nucleic acids all the sugars are dextro-rotatory
What 4 chemicals did the miller urey experiment produce?
1) amino acids
2) purines/pyrimidines
3) sugars
4) porphyrins
What are the 4 possible energy sources to produce the primordial soup?
1) sun
2) lightening
3) volcanic
4) radioactivity
What came first DNA or proteins?
Proteins produced by RNA self splicing
What are enzymes made of?
Proteins
Where do chemoheterotrophs get their carbon source and energy from?
consuming organic molecules
Where do chemoautotrophs get their carbon source and energy from?
carbon source- CO2
energy from oxidising inorganic substances
Where do photoautotrophs get their carbon source and energy from?
carbon source - CO2
energy source - from light
Where for photoheterotrophs get their carbon source and energy from?
carbon source from organic material
energy source - light
what are obligate anaerobes?
live exclusively be anaerobic respiration
what are obligate aerobes?
use exclusively oxygen for cellular respiration
what are facultative aerobes?
use oxygen if present but can grow by fermentation in an anaerobic environment
what are the 3 types on fossil evidence for prokaryotes?
1) fossil stromatolites
2) fossil microorganisms
3) carbonaceous matter
how are fossil microganisms preserved?
in rocks
how are fossil stromatolites formed?
in hyper saline conditions
what byproduct do cyanobacteria produce from the process of metabolism?
oxygen
what was produced when oxygen reached with dissolved iron in the ocean?
banded iron formations - BIFS
what is a facultative organism?
able to live in anaerobic and aerobic condittions
explain endosymbiosis of mitochondria?
- eukaryotes engulfed prokaryotic mitochondria
- anaerobe benefited from aerobic mitochondria in changing atmospheric conditions
4 similarities between mitochondria/plastids and prokaryotes
1) inner membranes have enzymes homologous to those found in living prokaryotes
2) splitting process similar to binary fission
3) both contain circular DNA not associated with histones or proteins
4) mitochondria/plastids contain tRNA and ribosomes more similar to prokaryotes than eukaryotes
what is it though the flagella and cilia originate from?
spirochaete bacteria - process of mitosis may be part of symbiosis from similar microtutubles
how does variation arise from mitosis asexual reproduction?
only variation is due to mutation
how does variation arises from meiosis sexual reproduction?
mutation , crossing over and independent assortment
what are the advantages of sex?
can combine advantageous mutations and shed harmful ones
when did sex evolve?
atleast 1.2 billions years ago
how old is the Earth?
4.6 billion years
what is an advantage or multicellular organisms?
division of labour
when did multicellular life evolve?
a billion years ago and several times to form different biological groups e.g. plants protists fungi
what is a problem with sex?
very inefficient
four main theories to why sex evolved?
1) adapting to change by evolving faster
2) historical accident
3) method of fending off disease
4) method of repairing genes - all genes need to line up in crossing over so if there is a problem the harmful mutation isn’t passed on
what is the cambrian explosion of animal life?
fossils appear at the same time worldwide filling numerous animal phyla with preservable hard parts
what are the 2 thought causes of the cambrian explosion?
1) change in co2 and o2 conditions
2) predation caused animals to evolve hard parts for protection
what are 4 features of a metazoan?
1) multicellular body
2) can manufacture protein collagen
3) reproductive cycle with gametes
4) has a nervous system
what is the difference between diploblastic organisms and triploblastic?
triploblastic have 3 germ layers and mesoderm layer allows them to develop organs
diploblastic - have 2 embryonic cell layers
how do edicaran organisms feed?
1) photosynthetic algae
2) take in through body wall
3) chemosymbiosis
what was life like in the late precambrian?
edicaran animals inhabit sea floor - triploblastic present but very small
what was life like in the early middle cambrian?
triploblastic predators evolve - most edicaran organisms become extinct or evolve hard shalls
what changes happened to organisms in the late cambrian?
predators more efficient and multicellular organisms evolve better armour and exploit more niches
