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72 Cards in this Set
- Front
- Back
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What are taxonomic groups? |
The hierarchical groups of classification - domain, kingdom, phylum, class, order, family, genus, species |
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What is the largest taxonomic group? |
Kingdom |
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What is hierarchial classification often referred to as? |
Linnaean classification |
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Why do scientists classify organisms? |
- To identify species - To predict characteristics - To find evolutionary links |
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What three domains are organisms separated into? |
Archaea, Bacteria and Eukarya |
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Why are mules infertile? |
Because horses and donkeys have a different amount of chromosones |
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What are common names? |
Species named after their physical characteristics, behaviour or habitat |
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Overview: Binomial nomenclature |
- Scientific naming of a species with a latin name made of two parts - The first word indicates genus, known as the generic name - Second indicates species, or the specific name - no two species have the same generic and specific name however they could have the same genus or specific name |
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What are the five kingdoms? |
- Prokaryotae - Protoctista - Fungi - Plantae - Animalia |
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Overview: Prokaryotae |
- Unicellular - No nucleus or other membrane-bound organelles. ring if naked DNA. small ribosomes - No visible feeding mechanism. absorbed through cell wall or produced by photosynthesis |
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Overview: Protoctista |
- Unicellular - Nucleus and other membrane-bound organelles - Some have chloroplasts - Some are sessile, others move by cilia, flagella or ameboid mechanisms - Autotrophic, heterotrophic or both, some are parasitic |
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Overview: Fungi |
- Unicellular or multicellular - Nucleus and membrane bound organelle. cell wall chitin - No chloroplasts or chlorophyll - No mechanisms for locomotion - Most have body or mycelium made of threads or hyphae - Saprophytic feeders. some parasitic - Most store food as glycogen |
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Overview: Plantae |
- Multicellular - Nucleus and membrane-bound organelles including chloroplasts. cell wall composed of cellulose - All contain chlorophyll - Most do not move - Autotrophic. photosynthesis - Store food as starch |
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Overview: Animalia |
- Multicellular - Nucleus and other membrane bound organelles. no cell wall - No chloroplasts - Move with aid of cilia, flagella or contractile proteins - Heterotrophic feeders - Food stored as glycogen |
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What is an example of a protein that has changed in structure over time? |
Haemoglobin |
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Overview: Eukarya |
- have 80s ribosomes - RNA polymerase contains 12 proteins |
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Overview: Archaea |
- 70s ribosomes - RNA polymerase of different organisms contains 8-10 proteins. similar to eukaryotic ribosome |
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Overview: Bacteria |
- 70s ribosomes - RNA polymerase contains 5 proteins |
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What are the kingdoms in the six-kingdom system? |
- Eubacteria - Archaebacteria - Protoctista - Fungi - Plantae - Animalia |
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Overview: Archaebacteria |
- Known as ancient bacteria - Can live in extreme environments such as, hot thermal vents, anaerobic conditions ans highly acidic environments |
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What is eubacteria? |
'True bacteria', found in all environments. Majority of bacteria are of this category |
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What is phylogeny? |
The evolutionary relationships between organisms |
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What are the advantages of phylogenetic classification? |
- Can be done without reference to Linnaean classification - Classification uses knowledge of phylogeny in order to confirm the classification groups are correct - Produces a continuous tree - Hierarchial nature of Linnaean classification can be misleading as it implies different groups within tue same rank are equivalent |
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Other than Charles Darwin, who else was important in developing thw theory of evolution? |
Alfred Wallace |
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Overview: Darwins research (famous example) |
- Finches on the Galapagos Islanda - Noticed that different islands had different finches, though they were similar in many ways so must have been related - Beaks and claws different shapes and sizes - Darwin realised this was due to different food availability, a characteristic the finches had passed on |
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What are the number of sources scientists use to study the process of evolution? |
- Palaeontology: the study of fossils and the fossil record - Comparitive anatomy: study of similarities and differences between organisms' anatomy - Comparitive biochemistry: similarities and differences between chemical makeup |
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What are fossils? |
Remains or impression of a prehistoric plant or animal preserved in rock |
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Where are the youngest fossils found? |
Found in the top strata of rock |
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What evidence for evolution is provided by the fossil record? |
- Simple organisms are found in older rocks - Sequence on which organisms are found matches their ecological links - Studying the similarity in the anatomy of fossil organisms can show how closely related organisms have evolved from the samw ancestor - Allow relationships between extinct and living organisms to be investigated |
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What is the disadvantage of using paleontology in evolution? |
- Fossil record is not complete - Many organisms are soft bodied and decompose quickly before they have a chance to fossilise - Conditions needed for fossils to form are not always present - Many fossils have been destroyed by the earths movement or lie undiscovered |
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What is a homologous structure? |
A structure which appears superficially different but had the same underlying structure |
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What is an example of a homologous structure? |
The pentadactyl limb |
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What is divergent evolution? |
Species diverge over time into two different species, resulting in a new species becoming less like the original one |
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What are the two most common molecules studied in evolutionary comparitive biochemistry? |
Cytochrome c and ribosomal RNA |
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What is the hypothesis of neutral evolution? |
- Most variability in the structure of a molecule doesnt affect its function - Changes that dont affect a molecules function are known as neutral - Since they have no effect it is not affected by natural selection |
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Overview: Comparitive biochemistry |
- Molecular sequence of a particular molecule is compared - Number of differences plotted against the rate the molecule undergoes neutral base pair substitutions - Estimate points organisms last shared a common ancestor - Species that are closely related have more similar DNA and proteins |
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What is intraspecific variation? |
The differences between organisms within a species |
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What is interspecific variation? |
Widest type of variation, between members of different species |
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What are the two factors that cause variation? |
- An organisms genetic material: differences inherited from parents leads to genetic variation - Environment: causes environmental variation |
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Overview: Alleles in genetic variation |
- Genes have different alleles - Within characteristics alleles produce differenr effects - Individuals in a species population may inherit different alleles of a gene |
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Overview: Mutations in genetic variation |
- Changes to the DNA sequence lead to changes in the proteins that are coded for - These protein changesbcan affect physical and metabolic characteristics - If mutation occurs in the gametes, it can be passed on to the organism's offspring |
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Overview: Meiosis in genetic variation |
- Gametes receive half the genetic content of a parent cell - Genetic material inherited from the two parents is randomised by independent assortment and crossing over - Leads to the gametes showing variation |
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How does sexual reproduction affect genetic variation? |
Offspring produced from two parents, inherits genes from each and therefore they differ from their parent |
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How does chance affect genetic variation? |
- Many different gametes are produced from parental genome - During sexual reproduction it is a result of chance as to which two combine - This leads to difference between siblings |
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What is an example of a characteristic solely determined by genetic variation? |
Blood type |
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What is an example of a characteristic solely determined by environmental variation? |
Scars |
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What is an example of a characteristic that comprises of both environmental and genetic variation? |
Skin colour |
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What is discontinuous variation? |
A characteristic that can only result in certain discrete values |
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What is continuous variation? |
A characteristic that can take any value within a range |
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What are the characteristics of a normal distribution? |
- The mean, mode and median are the same - Bell shape symmetrical about the mean - 50% of values are less than the mean and 50% are greater - Most values lie close to the mean |
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What is a student's t test used for? |
Used to compare the means of data values from of two populations |
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What is a Spearman's rank correlation coefficient used for? |
To consider the relationship between two sets of data |
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What three groups can adaptions be divided into? |
- Anatomical: physical features - Behavioural: Way an organism acts, can be inherited or learnt from parents - Physiological: Process that takes place inside an organism |
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What are some different types of anatomical adaptions? |
- Body covering: hair, scales, feathers and shells - Camouflage: Outer colour of an animal to enable it to blend - Teeth: Shape and type of teeth present in an animal's jaw are related to its diet - Mimicry: Copying another animal's appearance or sounds allows a harmless organism to fool predators into thinking its poisonous or dangerous |
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Overview: Marram grass |
- Is a xerophyte whos adaptions reduce the rate of transpiration - Curled leaves minimise surface area of moist tissue exposed to air and protects leaves from wind - Hairs on inside surface of leaves teap moist air close to leaf reducing diffusion gradient - Stomata sunk into pits, less likely to open - Thick waxy cuticle on leaves and stems |
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What is an example of a survival behaviour? |
An opossum plays dead and a rabbit freezes when they think they have been seen |
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What is an example of a courtship? |
Scorpions perform a dance to attract a partner and increase their chance of reproducing |
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What are two examples of seasonal behaviours? |
- Migration: Move between environments in parallel to environmental conditions - Hibernation: Period of inactivity in which an animal's body temperature, heart rate and breathing slow down to conserve energy |
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What two categories do behavioural adaptions fall into? |
- Innate: ability to do this is inherited, allows the organism to survive in the habitat in which it lives. e.g spiders making webs - Learned: learnt from experience or observation. e.g the use of tools like otters using stones to hammer shells off rocks |
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What are some examples of physiological adaptions? |
- Poison production: to kill prey and plants to protect themselves from being eaten - Antibiotic production: Kill other species of bacteria in the surrounding area - Water holding: storing water in the body, allows desert survival |
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What are analogous structures? |
Structures that have adapted to perform the same function but have a different origin |
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What is convergent evolution? |
Organisms evolve similarities because the organisms adapt to similar environments or other selection pressures |
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What is an example of convergent evolution? |
- Marsupials in Australia and placental mammals in the Americas - Evolved similar shape, type of locomotion and feeding techniques - Have very different methods of reproducing |
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what are two examples of the similarities between marsupial and placental species? |
- Mice: both small, agile climbers that forage at night for small foods. similar shape and size - Moles: Both burrow through soft soil to find worms. Have a streamlined body shape and modified forelimbs for digging. Velvety fur. However have different fur colours |
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What is selection pressure? |
Factors that affect an organism's chance of survival or reproductive success |
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What are the first two steps that natural selection follows? |
- Organisms within a species show variation in their characteristics that are caused by different genes - Organisms whose characteristics are best adapted to selection pressure survive and successfully reproduce. Less well-adapted organisms die or fail to reproduce. 'Survival of the fittest' |
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What are the last three steps that natural selection follows? |
- Successful organisms pass allele encoding advantageous characteristic onto their offspring and the reverse - Process is repeated for every generation and the proportion of individuals with characteristic increases in gene pool - Over very long periods of time the process can lead to the evolution of a new species |
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Overview: Antibiotic-resistant bacteria |
- MRSA (Methicillin-resistant Staphylococcus aureus) has developed resistance to many antibiotics - When bacteria replicates its DNA can change, mutation caused resistance to methicillin - Allele for resistance passed in to offspring, natural selection |
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Overview: Peppered moths |
- Most moths were pale coloured before industrial revolution - Trees became darker in revolution partly due to soot so darker moths began to survive and increase in frequency - Since clean air act of 1956 the opposite has begun to happen again |
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What is pre-adaption? |
- When an organism's existing trait is advantageous for a new situation - Existence of pre-adaption in an organism may help researchers to predict potential insecticide resistance |
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What is an example of an organism that evolved sue to opportunities that arose in their environment? |
- Flavobacterium, living in waste water from factories that produced nylon - Bacteria evolved to digest nylon with nylonases - Believed gene mutation occured as a result of gene duplication combined with a frameshift mutation |
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What is the founder effect? |
When a few individuals of a species colonise a new area, their offspring initially experience a loss in genetic variation, and rare alleles can become much more common in the population |
