Biology paper 1

Created by

Emily Bonser

Cards (587)

When do you use the spearman's rank correlation test
the investigation involved taking measurements
you are looking for associations between different measurements made from the same sample
When do you use the t test
the investigation involved taking measurements
looking got differences between measurements from different samples
When do you use the standard error and 95% confidence limits tests
the investigation involved taking measurements
looking got differences between measurements from different samples
When do you used the chi squared test
the investigation involved finding the number of individuals in particular categories
What does spearman's rank correlation coefficient tell you
whether their is a statistically significant correlation between two measurements from the same sample when you have 5-39 pairs of data
if the correlation is negative or positive
What is the chi squared test used to see
to see if the observed results are the expected resulst
What is a null hypotheisis
there is no significant difference between data
What is the null hypothesis always going to be in the chi squared test
there is no significant difference between the observed and the expected results
What does the t test determine
whether the means for two sets of data are significantly different
define a species
A group of similar organisms that can breed and produce fertile offspring.
What is classification?
The process of grouping things based on their similarities
What is taxonomy?
theory and practise of classification
Why is taxonomy important
Sense of order; enhance communication; make predictions about similar organisms
What does a phylogenetic system do
shows how closely related organisms are in terms of their evolution
What is hierarchy?
Groups within groups with no overlap
What is each group known as in hierarchy
taxon
What does binomial mean in classification
- give example
two name system
e.g. human - homosapiens
3 advantages for using binomial system
clarity - avoids confusion with common names
stability - Latin names not likely to change a words in other languages do
uniqueness - only one species can have a particular binomial
What does universally identified mean
a species that has the same binomial wherever you are in the world and whatever language you can speak
What are all the taxa in the hierachy
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Why is courtship behaviour necessary?
it enables individuals to recognise members of their own species
identifies a male that is capable of breeding
form a pair bond - to successfully raise young
synchronise mating - max probability of sperm meeting egg
What is the phylogenetic classification system based on
evolutionary relationships between organisms and their ancestors
classifies species using shared homologous features
arranges groups in hierarchy
What techniques can scientists use now to help them determine evolutionary relationships
genome sequencing
immunology
What is the type of classification called when only observations are used
artificial
How could genome sequencing be used to clarify evolutionary relationships between organisms
the order of nucleotide on one of the strands on DNA can be sequenced
this sequence can then be compared to the sequence of other species
organisms with DNA sequences that have the same DNA nucleotides in the same order are more closely related to those that do not
Why does DNA sequences of genes change over time
mutations
Why do changes in a gene allow you to relate organisms to eachother
the more recently they share a common ancestor the less time has lapsed for changes between the gene of two species to have occurred
Why must the same gene be compared for all species?
base sequences will be smaller
these bases will bind together
Why might comparing mRNA also be used to investigate evolutionary relationships between organisms
by comparing the mRNA between 2 species it shows similarities/ differences which genes are expressed
Why might cytochrome (a protein used in respiration) be a better protein to use as a comparison compared to haemoglobin to detect evolutionary links
haemoglobin can only be compared in organisms that contain this molecules in blood
cytochrome may be a better protein to use as all eukaryotes contain this protein for respiration
How could immunology be used to clarify evolutionary relationships between organisms
the antigen in serum form more closely related species (to humans) will have a similar shape to human proteins in serum
the tertiary structure of their proteins will be similar because:
- the DNA sequence and therefore primary structure will be similar
these antigen will be complementary shape to the rabbit to the rabbit antihuman antibodies
and will bind to these antibodies making antibody/antigen complexes which precipitate
What is a habitat
the place where an organisms normally loves characterised by the physical conditions and types of other organisms
What is an ecosystem
all of the living and non living components of a particular area
What is a population?
a group of individuals of the same species living in the same area at the same time
What is a community
all of the population of different species form a community in an area/ habitat/ ecosystem at one time
What is the difference between species diversity and genetic diversity
species diversity - is the number of different species and the number of each species in a community
Genetic diversity - the variety of genes produced by individuals that makes up the population of species
What does species richness measure
the number of different species in a community
What are the limitations of species richness as a measurement
it does not measure the number of different species in a community
two communities may have the same species richness but one may be dominated by one species
Why is index diversity better than species richness?
it takes into account the number of species present as well as abundance
if species population is low than it easier for one individual to die/ not reproduce
How does removal of hedgerows and woodland affect biodiversity and how to combat it
reduces the variety of habitats
- plant native trees and cut hedges in an A shape not rectangular