The origin of animals- Biodiversity
What are the modes of nutriotin for plants animals and fungi
Plants are autotrophic via photosythesis
Fungi are heterotrophic via growing on the resources needed
Animals are heterotrophs via digesting the needed resources
What the cell wall types in animals, plants and bacteria
Plants have a cellulose cell wall
Fungi have a chitin cell wall
Animals dont have a cell wall only a extracellular matrix and cell membrane
How do animals develop
By the development of the embryonic tissue after gastrulation takes place
All development is controlled by HOX genes and the hox gene evolution drives body plan evolution of animals
What do HOX genes do
They regulate development in animals by regulating the batteries of downstream target genes
Between blastula and gasteula there is the development of cell on the inside of the cell not just the outside of the cel
HOX genes are crucial for functional derivity
When did animals first evolve
During the Neoproterozoic era whihc was 1 billion to 542 million years ago
There were 2 smaller periods:
Cryogenian period where no fossils have been dated to
Ediacaran period where first fossil evidence found between 635-542 mya
What was the first fossil found
Found in the precambrien era 580 mya, was a sulphur metabolizing bacteria, that had no gastrulation evidence for development but could have been 1 -1000 cells variety in size on the organsim
What happend in the Cambrien Period in evolutionary terms
There was in increase in diversity between 540-250 mya, where animals starting having bilateral symmetry, appendages and segtemented bodies
What took place in the Cambrien explosion
All current phyla emerged due to the emergence of a predator and prey relaitionship due to better hunting and defence
Increae in oxygen levels
Evolution of the HOX gene to allow more development and diversity
Certabrates made thr transiton to land 365mya
What happened in the mesozoic era
There was the permian triassic mass extinction event where siberia flooded with laval for 600,000 years and covered most of northen hemisphere killing 96% of life
The there was the introducton and domination by the reptiles and first small mammals
What happened in the Cenozoic era
There was mass extinction event that wiped out the dinosaurs and then land was domianted by mammals and still is today
Lead to the rise and diversification of mammals
How are animals classified
By Body plan symmetry
Tissue Layers
Body Cavities
Proteostome VS Deuterostome development
How is Body plan symmetry used to classify animals
Sponges have no symmetry
Cnidaria and Diptoblasts have radial symmetry
Most other animalos have bilateral symmetry
How are tissue layers used to classify animals
Diploblast have 2 layers formed in gastrulation being an ectoderm and endoderm
Whereas most other animals are tiploblasts so have a 3rd layers fromed called the mesoderm to allow the development of true organs
How are body cavities used to classify animals
There is a cavoty within the mesoderm of molluscs and chordates
There is a cavity between the mesoderm and endoderm of roundworms
No cavity in flat worms
What is proteostome vs Deuteroeostome
In proteostome the anus develope before the mouth and mout develop from the blastopore - In Molluscs
In deutereostome the mouth develop first and the anus then develop from the blastopore - In Chordates
What is the classification of Bilateria
It is divided inot 3 groups:
Dueterostomia = The mouth develop before the anus and anus develop from the blastopore
Lophotrochozoa
Ecdysozoa which is moulting