27 Animal diversity (jorge/xmss) Flashcards
What are the key features that distinguish Kingdom Animalia from other kingdoms?
Multicellularity, eukaryotic cells, heterotrophy, motility, specialized tissues, sexual reproduction, embryonic development, Hox genes, lack of cell walls, internal digestion.
What is the role of Hox genes in animal development?
Hox genes control the body plan and organization during development, determining the anterior-posterior axis, guiding tissue and organ placement, and are highly conserved across species.
What are the two main methods of animal reproduction?
Sexual reproduction (involving gamete fusion and genetic variation) and asexual reproduction (budding, fragmentation, regeneration, parthenogenesis).
List the stages of embryonic development.
Fertilization, cleavage, blastulation, gastrulation, organogenesis.
What are the three types of body symmetry in animals?
Radial symmetry, bilateral symmetry, asymmetry.
Define diploblastic and triploblastic animals.
Diploblastic animals have two germ layers (ectoderm, endoderm), while triploblastic animals have three (ectoderm, mesoderm, endoderm).
What are the three types of body cavities in animals?
Acoelomates (no body cavity), pseudocoelomates (partially lined cavity), coelomates (fully lined cavity).
What is segmentation in animals?
The division of an animal’s body into repeated units, as seen in annelids, arthropods, and vertebrates.
Differentiate between protostomes and deuterostomes.
Protostomes: spiral and determinate cleavage, blastopore becomes mouth, schizocoely. Deuterostomes: radial and indeterminate cleavage, blastopore becomes anus, enterocoely.
Give examples of protostomes and deuterostomes.
Protostomes: Mollusks, annelids, arthropods. Deuterostomes: Echinoderms, chordates.
What are the major clades in the metazoan phylogenetic tree?
Basal metazoans (sponges, cnidarians), Bilateria (protostomes: ecdysozoa and lophotrochozoa, deuterostomes: echinoderms, chordates).
What types of data are used to construct and refine animal phylogeny?
Morphological data, embryological data, fossil evidence, molecular data (DNA sequencing, protein comparisons, genomics).
What key discoveries were made through molecular phylogenetics?
Ecdysozoa and Lophotrochozoa classifications, close relation of chordates and echinoderms, revised relationships among vertebrates, reclassification of simple animals.
Describe the earliest animals and their characteristics.
Simple, soft-bodied, aquatic, sessile or slow-moving, radially or bilaterally symmetrical, evolved from unicellular ancestors.
What was the significance of the Cambrian Explosion?
Rapid diversification of animal phyla, evolution of complex body plans, emergence of predation, increased ecological complexity, first chordates appeared.
What are some unresolved questions about the Cambrian Explosion?
Why did animal diversity increase rapidly? Were there earlier complex animals? What role did environmental changes and genetic evolution play?
How do mass extinctions impact animal evolution?
They reset evolutionary trajectories, drive diversification, create evolutionary bottlenecks, and may be occurring again due to human activities.
What are the key features that distinguish Kingdom Animalia from other kingdoms?
Multicellularity, eukaryotic cells, heterotrophy, motility, specialized tissues, sexual reproduction, embryonic development, Hox genes, lack of cell walls, internal digestion.
What is the role of Hox genes in animal development?
Hox genes control the body plan and organization during development, determining the anterior-posterior axis, guiding tissue and organ placement, and are highly conserved across species.
What are the two main methods of animal reproduction?
Sexual reproduction (involving gamete fusion and genetic variation) and asexual reproduction (budding, fragmentation, regeneration, parthenogenesis).
List the stages of embryonic development.
Fertilization, cleavage, blastulation, gastrulation, organogenesis.
What are the three types of body symmetry in animals?
Radial symmetry, bilateral symmetry, asymmetry.
Define diploblastic and triploblastic animals.
Diploblastic animals have two germ layers (ectoderm, endoderm), while triploblastic animals have three (ectoderm, mesoderm, endoderm).
What are the three types of body cavities in animals?
Acoelomates (no body cavity), pseudocoelomates (partially lined cavity), coelomates (fully lined cavity).
