Animal Evolution and Development Flashcards
(125 cards)
Where do animals fit into the tree of life?
Opisthokonts
What are animals most closely related to?
fungi
What are opisthokonts?
the two kinds of multicellular heterotrophs
What are some opisthokonts?
animals, fungi
What are the main differences between animals and fungi in terms of eating?
animals: ingest their food, digest inside bodies;
fungi: secrete enzymes, digest food outside of their bodies
What are most animal diseases?
bacterial
What are most plant diseases?
fungal
What does the term opisthokonts mean and to what cells does it refer?
“flagella coming out of rear” (sperm cells)
What are 11 unique characteristics of animals?
ingest food (hetrorophs); multicellular; sexual reproduction, diploid; most are mobile; aerobic; lack cell walls; glycogen (food storage); develop from a zygote (zygote develops into a gastrula); muscular and nervous tissues; HOX genes control body development
What are the steps of animal development?
- egg meets sperm –> zygote
- cleavage –> 8-cell stage
- cleavage –> blastula
- gastrulation
What is a blastula?
hollow ball of cells
What is gastrulation?
invagination of the hollow ball
Why does gastrulation occur?
sets up embryo to have different germ tissues
What is a blastopore?
opening in cell ball obtained from invagination of blastula
When are germ and somatic cells determined?
single cell stage
When is tissue fate determined?
gastrulation stage
Why do animals start life as a single cell?
so we can produce sexulally;
sexular recombination provides benefits
How many genomes are involved in development?
5 (? - at least 3?)
What genomes are involved in development?
zygote's; maternal; paternal; cytoplasmic factors deposited in the egg by the female; mitochondrial DNA
When does an embryo’s own genes (maternal and paternal combination) start to function?
gastrulation
When do cytoplasmic factors deposited in the egg by the female function in development and how do we know this?
control development to blastula stage;
an egg will develop into a blastula without sperm or nucleus
What are the 3 most characteristic processes of development in animals?
differentiation (into tissues, organs);
growth;
morphogenesis
What is morphogenesis?
development of new shapes, forms
When do the 3 most characteristic processes of development in animals take place?
after cleavage wehn the zygote’s own genes become active;
starts with gastrulation and continues through life of animal