animal diversity pt 1 (consumers -> tissues)

animals are what type of consumer?

heterotrophs + digest food inside the body

plants are what type of consumer?

autotrophs

fungi are what type of consumer?

heterotrophs + digest food outside the body using enzymes

→ are also specifically saprobes, parasites, and symbionts

animal cells lack a cell ___

wall

what is the most abundant protein in animals/animal cells?

collagen

what do animals use collagen for?

structural support in their cells because they lack a cell wall

what are the 3 junctions found between animal cells?

1) tight junction

2) desmosomes

3) gap junctions

what 2 specialized cells do animals have that plants and fungi do not?

1) nerve cells

2) muscle cells

tight junction

junction between animal cells that creates a barrier to prevent leakage of fluids between them

desmosome

junction that provides structural support by anchoring adjacent cells together, allowing them to withstand mechanical stress and move together

gap junction

open channels between animal cells to share material and communicate between one another

do most animal produce sexually or asexually?

sexually

what is the pathway for sexual reproduction in animals?

sperm + egg → zygote

zygote undergoes cleavage (cell divides) by mitosis → forms a morula (solid ball of cells)

morula becomes hollow → forms a blastula (hollow ball of cells)

blastula begins to form a germ layer (layers of embryonic tissue) in gastrulation → forms a gastrula (cell cluster)

zygote

a fertilized egg

morula

solid ball of cells

blastula

hollow ball of cells

gastrula

germ layers formed through gastrulation

what 2 stages can animals go through in development?

A) “mini” adult stage

B) larval stage

“mini” adult stage

mature and immature form are very similar (i.e. babies and adults have similar parts, only one is more mature)

larval stage

sexually immature stage that looks very different from the adult, will have to go through a metamorphosis to develop into adult stage (i.e. frogs, butterflies)

animals share a family of genes called “hox genes.” what are they responsible for?

group of genes that ONLY evolved in animals

genes that can influence the outcome of other genes

→ will turn the expression of other genes on/off

neoproterozic era

record of the first early animals on earth

what did animals look like during the neoproterozic era?

simplistic in structure, not complex

→ corals, molluscs, segmented worms

paleozoic era

rapid diversification of animals (the cambrian explosion)

what caused the cambrian explosion?

1) new predator-prey relationships

→ animals being preyed upon were forced to evolve

→ predators losing their food source were being forced to evolve

2) more oxygen in the atmosphere

→ cells carry out higher metabolic function leading to more complexity

3) hox genes evolved

→ more changes in genes causing variations in gene expression

mesozoic era

dinosaurs emerged

small, rodent-like mammals appeared

large coral reefs began to form

cenozoic era - present day

mass extinction of terrestrial and marine animals

→ these newly opened niches gave rise to larger mammals

asymmetry

having no symmetry in body plan

radial symmetry

any cut through the central axis will provide a mirror image

bilateral symmetry

only one cut dividing the animal into left and right halves creates a mirror image

porifera have what kind of symmetry?

asymmetrical

sponges and cnidaria have what kind of symmetry?

radial symmetry

cephalization

development of the head + sensory equipment located on the anterior end along with a central nervous system

→ lobsters have this

tissues

groups of specialized cells that are isolated from other tissues because they are separated by membranous layers

porifera (sponges) have specialized cells, but they do not have true _____

tissue; they have only cellular level development because they do not have membranous layers separating a group of cells from another group of cells