6 - Diversity and Relationships Between Organisms Flashcards
Define species
A group of the same organisms that can interbreed to produce fertile offspring
Way to remember 6 steps of natural selection
Monkeys Are Such Rascally Animals Around Food
What are the 6 steps of natural selection? Describe them
Mutation - variation is already present Adaption - environment favours these individuals Survival - of the fittest Reproduce - have offspring Alleles - pass these on Allele frequenting - allele changes
Define allele
A different form of the same gene
2 ways that prevents breeding from happening
Allopatric speciation
Sympatric separation
What is allopatric separation? (summary)
Geographical isolation
What is allopatric separation? (3)
Morphological differences
Seasonal breeding differences
Courtship behaviour
Why does courtship behaviour happen (4)
Determine of capable of mating
Recognition of species
Synchronised mating
Bond of paternity / maternity care
…………………. classification
Phylogenetic
Define hierarchy
Small groups within larger groups
Define taxon
Each level of classification
3 domains all organisms are sorted into first
Bacteria, Archaea, Eukarya
Way to remember the kingdoms
Did Katie Price Cheer On Fat Gay Strippers?
List of kingdoms in order
Domain Kingdom Phylum Class Order Family Genus Species
Name the kingdoms for people (extra I think)
Eukaryotes Animalia Chordata Mammalia Primate Hominidae Homo Homo-sapien
How to write the genus and species
Genus - capital letter
Species - italic or underlined
What is a phylogenetic tree?
Tree that shows which species has the most recent common ancestor
2 types of evidence for evolution
Observational and biochemical analysis
6 types of observational analysis
4 main, 2 extra
Fossils
Homologous structures
Analogous structures
Vestigial organs
Adaptive radiation
Embryology
How are fossils evidence for evolution?
Had parts don’t decay. Compressed and preserved in rock
Fossils as evince AO3 (2)
Most still buried
Soft bodies decay
What are homologous structures?
Pentadactyl limb - similar in many species
What is adaptive radiation?
Darwin - The finch’s beak differ on different islands
What are analogues structures?
Different structure for same purpose. Eg. both wasps and bats have wings but different species an not related
What are vestigial organs?
Organs that aren’t needed anymore (appendix and coccyx)
Why is embryology not valid?
Drawings weren’t from samples
Name 3 types of biochemical analysis
DNA sequencing
AA sequencing
MRNA sequencing
Why does AA sequence ≠ MRNA chain?
Degenerate so more than 1 codon codes for AA
What is the issue with MRNA sequencing?
Splicing removes introns and don’t know how it differs between people
Define species richness
Number of different species within a habitat
Define biodiversity
Number of species and individuals within each species
3 reason why variation is high near the equator
High sunlight and nutrient levels
Need to adapt for a harsh environment
Free radicals increase mutation rate
How to calculate diversity index
d= N(N-1 / n(n-1)
N = number of organisms of all species n = number of a particular species
A natural system has a ……… diversity index
High
Name the two types of ecosystems
Natural and agricultural
An area can only support a certain amount of ……………
Biomass
3 ways to increase food production
Fertilisers
Biotechnology
Genetic varieties
3 things that directly removes habitats
Removing woodland
Draining marshes / ponds
Overgrazing land
3 management strategies to help habitats
Plant hedges as field boundaries
Plant native trees on low species diversity land
Use nitrogen foxing crops and crop rotation for nutrients
Con of management strategies
Increase food costs
What is discontinuous variation?
Categorising data
2 discontinuous variation examples
Blood type
Eye colour
What causes discontinuous variation? (2)
Mostly a genetic mutation
Rarely due to the environment
What is continuous variation?
Gradual transition between two extremes
2 continuous variation examples
Height
Weight
Shape of a continuous variation graph
n
Define standard deviation
Measure the spread of results around the mean
Define mean
Sum of values divided by number of values
% in standard deviation 1
68%
% in standard deviation 2
95%
What does it mean if error bars overlap?
The population isn’t very different
Define standard error
Measures the likelihood that the mean would be the same in another sample
Equation for standard deviation
SF = √ ∑ x^2 - ̅x ^2
Equation for standard error
SE = σ/√n
Two types of causes for variation
Environmental and genetic
What is environmental variation
Depends on the environmental. Includes sunlight and water
What are genetic causes for variation
Meiosis and mutation
Three ways meiosis cases genetic variation
Random fertilisation
Independent segregation
Crossing over
Define random fertilisation
Gametes produced by mating pairs fuse together at random and there are potential genotypes among their offspring
Define independent segregation
How chromosomes line up at prophase 1
What is independent segregation also known as
Random assortment and independent assortment
What is crossing over?
XX. There is a chiasma where the sister chromatids cross
Name two types of mutation
Chromosomal and gene
What is chromosomal mutation?
Changes the full chromosome
Define nondisjunction
Chromosomes that usually separate in meiosis stay together so whole bivalent does to poles. Have an extra chromosome
Define mutation
Any stable heritable change in the genetic code
2 types of gene mutation
Substitution / point
Deletion / frame shift
Do substitution mutations always have an impact?
No - degenerate and intron
Do deletion mutations always have an impact?
Unless at the end, YES. Shift triplet code
Define polygenetics
Characteristic controlled by more than one gene
Give an example of Lamarck’s theory
Giraffes have a long neck by stretching them
List the three types of natural selection
Stabilising
Directional
Disruptive
Describe stabilising selection (2)
Selection pressure at both extremes
Maintains the average
Example of stabilising selection
Birth weight before modern medicine
Describe directional selection (2)
Selection pressure at one extreme
Shift of mean
Example of directional selection
Giraffes having long necks
Describe disruptive selection (1)
Selection pressure against mode
Example of disruptive selection
Passerine birds
What is sickle cell anaemia?
Haemoglobin condition where a change in the pH causes it. If have 1 allele, protect against malaria
How are people antibiotic resistant?
High selection pressure
Rapidally and asexually reproduce
High mutation rate
Why do bacteria have a high mutation rate?
DNA is in plasmids in cytoplasm so little protection
