Chapter 31: Fungi
· fungi are most closely related to ANIMALS
· body structure: made of tiny filaments called HYPHAE, cell walls are made out of CHITIN, hyphae form a MYCELIUM
· septate: SEPTA form crosswalls in the hyphae; SEPTATE fungi are fungi with septa
· coenocytic: fungi that lack crosswalls (lack septa)
· nutrition: fungi are absorptive heterotrophs (they secrete digestive enzymes that partially digest their food so they can absorb it)
· reproduction:
o sexual reproduction: often go through this when environmental conditions are poor
§ can use spores for sexual reproduction (ex. asci, basidium, zygosporangia)
§ release of pheromones brings hyphae of fungi together, they fuse
§ plasmogamy: union of 2 cytoplasms
§ karyogamy: fusion of 2 nuclei, forms diploid cell
· meiosis restores haploid condition
o imperfect fungi: only have asexual reproduction, ex. yeast
o asexual reproduction: can also be in form of spores (ex. conidia)
· haustoria: extensions of fungi present in some species of fungi, help the fungi feed on plants and animals
· mycorhizzal fungi: fungi help plant roots take up phosphate, plant helps fungi take up nutrients
Chapter 32: Intro to Animal Diversity
· reproduction/development: DIPLOID stage is dominant
o ZYGOTE undergoes CLEAVAGE to form a BLASTULA which undergoes GASTRULATION to form a GASTRULA
§ cleavage: cell division without growth
o protostome development: cleavage is SPRIAL and DETERMINATE, the blastopore of the gastrula develops into the MOUTH
o Deuterostome development: cleavage is RADIAL and INDETERMINATE, the blastopore of the gastrula becomes the ANUS
· ecdysozoans: shed through ECDYSIS (molting or shedding)
· lophotrochozoans: some have Lophophore (crown-shaped feeding structure) or trocophore (larval stage)
· germ layers
o ectoderm: forms outer cover and central nervous system (ex. brain)
o mesoderm: forms muscles and organs
o endoderm: lines digestive tube
o Diploblastic: organism that has 2 germ layers (ectoderm and endoderm)
o Triploblastic: organism that has 3 germ layers (ectoderm, mesoderm, and endoderm)
· coelom: body cavity derived from the mesoderm
o acoelomate: lacking a coelom (body cavity)
o Pseudocoelomate: has a “fake coelom”, derived from mesoderm AND endoderm (not just mesoderm)
o coelomate: has a true coelom, derived only from the mesoderm
o metamorphosis: change in FORM
Chapter 33: Invertebrates
· sponges: lack symmetry, lack true tissues, sedentary (don’t move)
o how do they feed? suspension feeders, use CHOANOCYTES to move water to help find food
o how do they reproduce? hermaphrodites (produce both male and female gametes)
· cnidaria
o body plan: sac with a central digestive compartment, single opening is mouth and anus, 2 forms: polyp (sedentary) and medusa (mobile)
o use CNIDOCYTES for feeding
· Platyhelminthes
o FLATWORMS
o body plan: acoelomates, no organs for gas exchange, most are parasites
· rotifers
o reproduction: PARTHENOGENESIS (female species don’t need males to reproduce unless environmental conditions are poor)
· molluscs
o basic body plan: 3 main body parts (foot, mantle, visceral mass)
o torsion: developmental process where visceral mass twists so that anus ends up above head
· annelids
o segmented worms
o reproduction: are hermaphrodites
· nematodes
o roundworms
o important parasites of humans and plants (importance is that they can be harmful to us)
· arthropods
o majority of extant (living) animals are arthropods
o derived characteristics: exoskeleton made of chitin, segmented, have an open circulatory system and organs specialized for gas exchange
· insects
o derived characteristics: have head, thorax, and abdomen, complex digestive organs, and 3 pairs of legs
o incomplete metamorphosis: egg, nymph, adult
o complete metamorphosis: egg, larva, pupa, adult
o have a tracheal system
· crustaceans
o have branched appendages specialized for feeding and movement
· echinoderms (“spiny skin”)
o NO TERRESTRIAL SPECIES
o slow moving or sessile
o have a water vascular system and tube feet
Chapter 34: Vertebrates
· chordates
o derived characteristics:
· notochord: longitudinal
· dorsal-hollow nerve chord
· muscular post-anal tail
· pharyngeal slits
· craniates
o chordates with a head
o unique feature: NEURAL CREST
· vertebrates
o Deuterostomes
o bilaterians (bilateral symmetry)
o have a backbone
· gnathostomes
o vertebrates with true jaws
· jaws developed from skeletal supports of pharyngeal slits
o enlarged forebrain, enhanced sense of smell and vision
o tetrapod development: have limbs and feet, developed when fins became more limb-like
· amphibians
o FIRST CHORDATE to spend a portion of their lives on land
o amphibian: “both ways of lives”
o rely on moist skin and moist environments
· reptiles
o derived characteristics:
· have scales to protect from drying and abrading
o development of an amniotic egg containing 4 specialized membranes to protect the embryo
· allowed vertebrates to move to terrestrial environments
o endothermic: generates body heat through metabolism
o ectothermic: absorbs heat externally from the environment
· mammals
o derived characteristics: mammary glands, hair, are endothermic, have diaphragms
· montremes: no nipples
· marsupials: have pouch
· eutherians: have placentas, longer period of pregnancy
· evolution of humans
o humans are members of PRIMATE APE group
o human evolution is not a “ladder” leading directly from early human-like groups to current species (Homo sapiens); it is branching
o hominin species:
· Homo habilis: oldest species of hominin groups
· Homo ergaster: first fully bipedal (walking upright on 2 feet)
· Homo erectus: first hominin to leave Africa
· Homo neanderthalensis: lived in Europe, large with prominent brow
· Homo sapiens: originated in Africa, what is present today