6. Form And Function Of Animals Flashcards
What are protists?
A diverse collection of Eukaryotic organisms that do not fit into animal, plant, bacteria, or fungi groups
What are the 3 domains of life?
- Eukarya
- Bacteria.
- Archaea.
What are 2 broad categories of living organisms?
- Prokaryotes
- Eukaryotes
What are the 4 components of the cytoskeleton?
- Microtubules.
- Centrosome.
- Intermediate filaments.
- Microfilaments.
What do microtubules do?
Form the miotic spindle and maintain cell shape.
What are microfilaments?
Fibrous proteins that form the cellular cortex.
What is a centrosome?
A microtubule- organising centre.
What are intermediate filaments?
Fibrous proteins that hold organelles in place.
What are animals?
Multicellular heterotrophic eukaryotes with tissues developed from embryonic layers.
What is a heterotroph?
An organism that obtains its nourishment and energy by consuming organic matter from other organisms, as opposed to producing its own through photosynthesis or chemosynthesis.
What are the 3 main germ layers?
- Ectoderm.
- Mesoderm.
- Endoderm.
What are embryonic layers?
Distinct tissue layers that develop during the early stages of embryogenesis and give rise to various tissues and organs as the embryo develops.
Also known as germ layers.
What are tissues?
A group of cells that have a similar structure and that function together as a unit.
What are organs?
Structures made up of two or more tissues organised to carry out a particular function.
Approximately how many animal species are there?
1.3 million to 10 million
What are Hox genes?
Homeobox genes only found in animals that set up the correct positioning of the body parts of the animal during embryo development.
What are homeotic genes?
Genes that ensure that the formation of the animal’s shape occurs correctly (regulate morphogenesis).
What are homeobox genes?
A subtype of homeotic genes that are key in regulation of morphogenesis.
When was the last common ancestor of animals?
Approximately 770 million years ago.
What species was the first ‘split’ from the common animal ancestor?
The porifera (the sponges).
What is the proposed common evolutionary ancestor of all animals?
The choanoflagellate protists.
Because of their similarity to sponge choanocyte cells
What is phylogeny?
The evolutionary lineage and relationship history of organisms, depicted through branching patterns and common ancestors.
What is a lineage called when it evolves early and remains unbranched from the evolutionary root?
A basal taxon.
What are two lineages that stem from the same branch point?
Sister taxa.
What is a branch with more than two lineages?
Polytomy.
What is the study of naming, describing, and classifying organisms?
Taxonomy.
Who created the binomial classification system?
Carl Linnaeus.
What are the 8 taxonomical groups (based on morphology)?
- Domain.
- Kingdom.
- Phylum.
- Class.
- Order.
- Family.
- Genus.
- Species.
What are extant species?
Species that are living in the present day.
the opposite of an extinct species
What is a vestigial structure?
A biological structure that has lost a major ancestral function and is usually drastically reduced in size.
What are the 3 main types of animal body plans?
- Asymmetry.
- Radial symmetry.
- Bilateral symmetry.
What are asymmetry body plans?
Animals that lack symmetry regardless of how they are cut.
These include the porifera (sponges).
What are radial symmetry body plans?
Animals that have symmetry radiating from a central cylinder - there are multiple planes of symmetry.
These include the phylum Cnidaria (jellyfish and sea anemones).
What are bilateral symmetry body plans?
Animals with two lines of symmetry.
1. Dorsal and ventricle (top and bottom).
2. Anterior and posterior (front and back).
Two ‘ends’ as well as two pairs of symmetrical sides.
What animal lacked tissues?
Sponges.
What is gastrulation?
An early stage of embryonic development where a blastula reorganises into a gastrula.
Are most animals haploid or diploid?
Diploid.
Most animals have diploid somatic cells and generate haploid gametes through meiosis.
What is the non-living layer in diploblast sponges called?
Mesoglea.
What are diploblasts?
Animals with only two germ layers.
Diplosblasts have a non-living layer instead of a mesoderm layer.
What are triploblasts?
Animals with three germ layers.
Ectoderm, endoderm and mesoderm.
Animals with radial symmetry are…?
Diploblasts.
Animals with bilateral symmetry are…?
Triploblasts.
What are 4 benefits of the coelom’s evolution?
- Shock absorption.
- Organ movement and development.
- Gas and nutrient diffusion.
- Enhanced animal mobility.
What is the coelom?
A cavity between the digestive tract and the outer body wall.
Derived from mesoderm and filled with fluid or air, housing vital systems like digestion, circulation, and reproduction.
What animals have a coelomic cavity?
Most triploblast animals.
What are triploblasts without a coelom called?
Acoelomates.
What are triploblasts with a true coelom called?
Eucoelomates.
What are triploblasts with a false coelom called?
Psuedocoeloms.
The false coelom is derived from mesoderm and endoderm.
What are marsupials?
A distinct group of mammals that carry and nurse their underdeveloped young in pouches (marsupium).
What are monotremes?
Egg-laying mammals that posses both reptilian and mammalian characteristics in their reproductive and physiological traits.
These include the platypus and the echidna.
What percentage of animal species are invertebrates?
96%
What percentage of animal species are insects?
Over 50%
What is segmentation?
The division of some animal and plant body plans into a series of repetitive segments.
What is cephalization?
Having a head.
What are tentacles?
Fleshy appendages that surround the mouth.
What is an exoskeleton?
An external framework, made of rigid materials like chitin, used for supporting and containing the body of an invertebrate animal.
What is an endoskeleton?
An internal framework of bone and cartilage, supporting the body of vertebrate animals.
What sub-phylum do mammals, lizards, birds, and fish belong to?
Vertebrata
The sub-phylum of the phylum Chorodata.
What are parapodia?
A pair of fleshy, paddle-like appendages on each segment of marine worms.
