Biology Topic-4 Flashcards
Define biodiversity
Variety of living organisms in an area
Define species diversity
Number of different species
Define genetic diversity
Variation of alleles within a species
Define Endemism
Species unique to a single place
What does maintaining genetic diversity mean?
Ensuring a wide gene pool.
More likely for the species to survive due to the range of genes
Species likely to better evolve
What does genetic drift mean?
Random changes in the frequency of alleles from generation to generation
Very noticeable in small populations
Aim to reduce this by using healthy animals in breeding
What is inbreeding depression?
New alleles less likely to join the gene pool if breeding is done with related individuals
Homozygous tend to rise heterozygous decrease
Many recessive alleles can be harmful
Offspring can be smaller, unhealthy and don’t live as long
Define allele
A form/ type of a gene
Define gene
A sequence of bases coding for a protein
Define species
A group of organism that can breed and produce fertile offspring
Define species richness
Number of different species in an area
Define species evenness
How close in number each species is in an environment
How to calculate biodiversity within a species
Heterozygosity index (no of heterozygotes/ population)
How to calculate biodiversity in a habitat
Species richness (no of different species)
How to calculate biodiversity between habitats
Biodiversity index N(N-1)/ E n(n-1)
What are the hardy weinberg equations?
p+q=1
p^2 +2pq+ q^2= 1
p is dominant
q is recessive
Define niche
The role that an organism plays in an environment and how it affects its survival
Name the 3 different adaptations
Physiological - process inside body e.g hibernation
Behavioural- actions e.g playing dead
Anatomical- structural features e.g streamlined shape
Define speciation and the cause
Formation of new species .
Reproductive isolation- individuals isolated for a long time and mutate until are recognised as different species
e.g on different islands or blocked by mountains
Name the 2 ways of classification
Hierarchical system
Phylogenetic system
Describe how organism are classed in the phylogenetic system
Based on evolutionary origins. figured by analysing DNA
Hierarchy means smaller groups put into larger groups
Why are Nitrates needed? What would deficiency look like?
Needed for amino acids
Needed for growth
Deficiency - yellow leaves, stunted growth
Why is Magnesium needed? What would deficiency look like?
Needed for chlorophyll formation
Needed in photosynthesis
Deficiency - yellow leaves + red tinges, slow growth
Why is Calcium needed? What would deficiency look like?
Needed for cell wall formation
Needed for structure
Deficiency - stunted growth, no new cells
Devise method of looking at plant stems
Cut as thinly as possible
Toluidine blue stain
Cover slip
Start of with lowest magnification
What makes plants strong
Microfibril arrangement
Lignin
Secondary cell wall
Positives of using plant fibres in products
Sustainable
Less fossil fuel used
Biodegradable
Easier to extract and process than oil
Use of starch in sustainability
Bio plastics
Bio ethanol
Advantages and disadvantages of seed banks
A- cheaper than full plants, large numbers stored, less labour, safe from damage
D- expensive to test viability, difficuly to collect
What conditions are necessary for the Hardy Weinberg equations to be true?
No natural selection
No migration
No mutations
A large population
