Evolution, Ecology and Biodiversity Flashcards
What is the binomial system?
Each organism is given a specific name of two Latin words
The structure of the names of species?
- the first name is the noun (generic)
- the second name is the adjective (specific name)
Generic name
It begins with a capital letter
Specific name
Begins with lowercase letter
Taxonomy
The science of classification. I relies on morphological characters.
How species are grouped?
- similar species are grouped together into the same genus ( genera plural)
- similar genera are grouped into families
What is taxa?
the general name for groups or categories within the classification system
The hierarchy of taxa
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What is the classification of living organisms?
- Archaea - extremophile prokaryotes
- Eubacteria - all true bacteria
- Eukarya - all eukaryotic cells
Components of Archea
- 70s ribosomes
- some introns
- few plasmids
- no membrane bound organelles
- few species with histones
Components of Eubacteria
- 70s ribosomes
- no introns
- many plasmids
- no membrane bound organelles
- no species with histones
Components of Eukarya
- 80sribosomes
- introns
- absent plasmids
- membrane bound organelles
- many species with histones
What are plants?
Terrestrial multicellular organisms that are adapted to life on lands or in aquatic habitats
What organisms are classified as plants?
- eukaryotic organisms that have a wall containing cellulose
- autotrophic organisms, manufacturing sugars into photosynthesis in their chloroplasts
What are the two stages/generations of complex life cycle?
- gametophyte generation that produces gametes
- sporothyte generation that produces spores
What are the main characteristics of plants?
- kingdom: plantae
- photosynthetic
- chlorophyll
- cellulose in the cell wall
- permanent vacuoles
- storing starch
Describe mosses and liverworts
- non-vascular plants
- stems radial symmetry (mosses)
-stems bilateral symmetry (liverworts) - no true leaves or roots
- no cuticle
- reproductive structures are called sporangium
- for example mosses, liverworts, hornwarts
Describe ferns
- leaves
- roots
- non-woody stems
- divided leaves
- reproduction includes sporangia
Describe conifers
- trees
- woody stems
- waxy narrow needle-like leaves
- vascular system
- reproduction: microsporophylls (male) - in air bladders and take place in water/air dispersals and macrosporophylls (female) - ovule on the cone scale
Describe flowering plants
- roots
-stems
-leaves - xylem/phloem
- waxy cuticles
- variety of pollen transfers
- produce seeds
Differences between dicotyledons (sunflowers) and monocotyledons (meadow grass)
sunflowers:
- 4 or 5 parts of flowers
- branched roots
- vascular bundles of stem in a ring
meadow grass:
- 3 parts of flowers
- unbranched roots
- vascular bundles of stem numerous and scattered
characteristic features of the animal kingdom
- multicellular eukaryotic organisms
- highly specialized cells
- specialized tissues that form organs
- nervous system to coordinate body
- their life cycle is diploid
- constant movement
- bilateral
- cephilisation
Post-fertilization process in animals
Zygote divides to produce and embryo, which early in the development becomes a characteristic hollow ball of cells- blastula
What is blastula?
hollow ball of cells
What is cephilisation ?
Evolutionary trend towards the centralization of neural and sensory organs in the head
Six main phyla in animal kingdom
- the sponges
- jellyfish
- flat worms
- segmented worms
- mollusca
- jointed-limbed animals
What is clade?
All of the organisms, both living, descended from a common ancestors
What is cladistics?
- method of classifying organisms based on the construction and analysis of cladograms
- each clade consists of an ancestral organism and all of its evolutionary descendants
- members of a clade will possess common characteristics as a result of their shared evolutionary lineage
What is cladogram?
evolutionary tree that shows points at which clades diverged from a common ancestral form
- there is a positive correlation between the number of differences between two species and time difference since they diverged from a common ancestor
How the eukaryotic cells evolve from the prokaryotes?
They formed a symbiotic relationship with the cells they engulfed (endosymbiosis). The vital organelles that developed in eukaryote cells were mitochondria for aerobic respiration and chloroplasts for photosynthesis. Primitive eukaryotes acquired mitochondria by engulfing aerobic bacteria and chloroplasts were acquired by engulfing photosynthetic prokaryotes.
What is the evolution?
It is the process by which living organisms are formed, by gradual change from previous organisms. It can occur due to mutations, selection pressures, and barriers to gene flow.
What are the 3 evidences for evolution?
- study of fossils
- artificial selection
- comparative anatomy
How fossils prove the theory of evolution?
- remnants of past life uncovered from the crust of the earth. method of radioisotope revealed the ages of the rock and the fossils in them, which shows the skeletal parts
How artificial selection prove the theory of evolution?
- process by which all the plants and animals used by humans have been developed from wild species by selecting individuals with desirable traits and breeding from them. for instance the cow has been bred to have a straight back and she is the product of artificial selection
How comparative anatomy prove the theory of evolution?
- shows that although organisms adapted to different habitats, their underlying organization can be similar. They have homologous structures which means that they are similar because they have common ancestry. There are also analogous structures, which means that they are similar in structure but have different origins
What is the adaptive radiation?
Describes rapid evolutionary diversification of single ancestral line. It occurs when members of a single species occupy a variety of distinct niches with different environmental conditions.
Natural selection
better adapted organisms survive to produce a greater number of viable offspring. Individuals who are better adapted tend to survive and produce offspring while those less well adapted tend to die
How does natural selection works?
- populations produce more offspring than the environment can sustain
- struggle for survival increases
- organisms that have more favorable traits will survive
- they will pass those characteristics to their offspring and that will lead to a change in the characteristic of the population