Unit 3 Topic 1
an abiotic factor is
Non living components of an ecosystem
Describe what a keystone species is
A keystone species is any species that performs a critical role in an ecosystem such as control populations, maintains biodiversity or provides critical resources.
First stage in production of Proteins
Transcription
What does this sentence describe?
Similar structures that evolved from a common ancestor such as bones humans, cats, bats, and whales have in common.
Homologous structures
Number of chromosomes in human DNA
46, 23 pairs
Name one feature of the Linnaean classification system.
Hierarchical groups (taxa)
Based on Physical features
Binomial nomenclature for naming organisms
50 dolphins are captured, tagged and released. A month later, 20 dolphins, of which 4 are tagged are captured. Use the Lincoln Index to estimate the total population of dolphins.
250
a group of three nitrogenous bases on the mRNA molecule are called an....
anticodon
If a small number of tree frogs migrate to a mat of vegetation that is already home to an established population of tree frogs and introduce new alleles into the native population's gene pool, this change is referred to as what?
Gene flow
The blood types
A, B, AB, O
an example of an interspecific hybrid which reinforces the definition of a species being that individuals can reproduce to create fertile offspring.
mule, zorse, zonkey, liger
List 3 characteristics of pioneer species that make them effective colonisers.
ability to fixate nitrogen, tolerance to extreme conditions, rapid germination of seeds, ability to photosynthesise
three types of point mutations
insertion, deletion, substitution
What is this sentence describing?
Body structures on different organisms that are similar in function but did not evolve from the same ancestor (bird wing and butterfly wing)
Analogous structures
What does this statement describe?
Two species competing for the same resources in the same niche can't coexist.
Competitive Exclusion Principle
assumptions include common ancestry, bifurcation and physical change. What am I?
Cladistics
name for the stages of succession
seres
when each allele expresses itself equally in the phenotype
codominance
Describe the two specific examples of genetic drift.
1. Founder effect - a small population colonises a new area and by chance have different allele frequencies compared to the original population.
2. The bottleneck effect - a catastrophic event such as an earthquake causes a large proportion of the population to die. The small population left have different allele frequencies compared to the original population by chance.
Which animal has the largest male anatomy to body ratio?
Barnacle
Ecologists want to gather data on species richness and abundance along a rock shore. Describe the process of stratified sampling they should use.
- Use a belt transect with samples taken at regular intervals e.g. 5 m.
- To minimise bias have clear criteria for including organisms, do multiple transects, assign the position of the transect lines using a random method.
- Display data in a bar chart with error bars using standard error.
Describe two ways nitrogen is transformed and one way it is transferred through the biotic components of ecosystems.
Transformed - denitrification where nitrites in soil are converted to nitrogen gas in the atmosphere and nitrification where nitrogen gas is fixed to nitrites in soil.
Transferred - herbivores eat plants and the nitrogen is transferred from one organism to another.
What is the function of restriction enzymes
responsible for cutting DNA at particular sites
Describe what sympatric speciation is and give an example
New species are formed even when there is no geographical isolation. Can be due to niche differentiation or polyploidy (in plants).
E.g. apple maggot
Why do biologists look forward to casual Fridays?
They’re allowed to wear genes to work.