Variation and classification Flashcards
What are the types of variation
- Interspecific variation: variation between species
- Intraspecific variation: variation within species
Genetic variation
- The mixture of alleles of genes inherited affect the phenotype of an organism genetic variation is due to :
- Random mutations : chromosomes mutations, DNA mutations
- Recombination of alleles : Crossing over during prophase 1 , meiosis, independant assortment of chromosomes during metaphase 1 of meiosis,independant assortment of chromosomes during metaphase 2 of meiosis, random fertilisation of genetically different haploid gametes
Environmental Variation
- Phenotypic variation caused by differences in the environment which include :
- climate, diet , lifestyle, language , scars,sex determination in turtles id determined by temperature of water and hydraged flower colour depends on soil Ph
- Etiolation: Plants grown without enough light may become etolited and they will grow tall and spindly with long internodes
- Chlorosis : Plants may develop yellow leaves due to lack of chlorophyll this may be due to lack of magnesium or iron ions in the soil , light or viral infection. The plant has the gene to produce chlorophyll byt the environment is preventing them from being expresed
- Diet: Body, height, deficiency diseases
Types of variation
Discontinous variation:
* phenotypes fall into distinct and discrete catergories with no or low intermediate values ,
* Bar chart
* monogenic - controlled by one gene
* codominace and multiple alleles
* may be controlled by two genes epistanic ( one gene affect the expression)
* the environment is likely yo have little to no effect on the phenotype
* examples: blood groups, tongue rolling , pea colour
Types of variation
Continous variation:
* A continous range of vaules between two extremes, forming a normal distribution curve
* Usually controlled by serveral distribuation curve
* polygenic - serveral genes
* provides an additive effect on phenotype
* smaller effects causes quantitave data
* influnced by the enviroment
* examples: weight,height, resting heart rate etc
Species
- A species is a group of organisms; very similar in appearance , anatomy, physiology, biohemistry and genetics
- Members of a species can bread together (interbreed) to produces fertile offspring
Phylogeny
- The study of evolutionary relationships between species
- Shows how closely related different species are
- Can be displayed on a phylogentic tree
- Species that more closely related appear closer to one another on the cladogram
Convergent evolution
- Is the evolution of similar features in distantly related species
- Convergent evolution creates analogous structures the have similar form or function but have evolved seprately
Classification
- Scientist use classification to group l;ife on earth , using similarites and differences between organism to classify them
- Classical ‘Linnaean’ classification relies on the observable features of an organism.:
- Taxon : Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
- Humans: D= Eukaryotes,K= Animalian, P= Chordata, C=Mammalia, O= primates , F=hominidae, G= Homo, S= sapiens
The Binomial System
- Started by carl linnaeus
- Used Latin as it is a universal language
- Universal:
- Organisms may have more than one local name
- An organism can be referred to as something in one part of the world and something completely different elsewhere
- A local name can refer to a wide range of different organisms
- Translation of language or dialects may give different names
Rules for binomial system
- The first name is Genus always has a capital letter
- The second name is the species always is a lower case first letter
- If typing the name it must be in italics
- If you are handwriting the name it must always underlined
5 Kingdoms
What are the features of the Prokaryrotes kingdom ( Prokaryotae)?
- No nucleus
- Loop of DNA that is arranged into chromosomes
- Has naked DNA (no histones)
- No membrane bound organelles
- Smaller ribosomes than other groups
- Smaller cells than eukaryotes
- Free living or parasitic
5 Kingdoms
What the features of the Protoctists kingdom (Protoctista)?
- Eukaryotic
- Single-celled or groups of similar cells
- wide varity of forms
- Their underlying feature is that they do not fit into any of the four organisms
- Display various plant-like or animal-like features
- Mostly free living
- Autotropic (makes its own food) or heterotropic nutrition ( food from other organisms)
5 Kingdoms
What are the features of the Fungi kingdom?
- Eukaryotic
- Exist as single cells (yeast) or have a mycelium that consists of hyphae
- Cell walls made of chitin
- Cytoplasm is multinucleate
- Mostly free-living
- Saprophytic nutrition – use extracellular enzymes to break down matter and then absorb the nutrients
- Most store food as glycogen
5 KIngdoms
What are the features of the Plants kingdom (plantae)
- Eukaryotic
- Multicellular
- Cell walls made of cellulose
- Autotrophic nutrition: photosynthesis (and absorption of mineral ions) to synthesise large organic molecules.
- Contain chlorophyll
- Store food as starch
