Diversity of Living Things - Chapter 3 Flashcards
General characteristics of fungi
eukaryotic, heterotrophic, absorptive
the aboveground parts of the fungi are the reproductive parts, only purpose is to spread spores
hyphae = fine filaments of cytoplasm, nuclei, organelles
mycelium = the network of hyphae
Importance of fungi
decomposers food for human consumption toxic waste treatment assist with plant growth helps build soil
What fungi need to survive
food source that they can liquify
water or moisture so they don’t dry out
exchange of gas, cellular respiration
Fungi reproduction
can be sexual or asexual
spore = haploid reproductive structure, capable of growing into a new individual
fungi are grouped on the type of spore produced and the structure created to release it
Lifecycle of fungi
spore with a haploid nucleus germinates and produces hyphae
two hyphaes fuse
the cell grows into a new mycelium with 2 haploid nuclei
mycelium produces mushroom cap and basidia
in the basidia, the two haploid nuclei fuse forming a zygote
zygote undergoes meiosis and produces spores
Anatomy of fungi
cap = holds the gills gills = hold the basidia and the spores stipe = raises spores off the ground so it can be airborne
Saprophytic
recyclers, break down dead organic matter
secrete digestive enzymes that liquify organic matter
absorb nutrients through mycelium
Parasitic
feed on living cells
hyphae penetrate host cell without killing it immediately
liquifies contents of host and absorbs through mycelium
Mutualistic
example = mycorrhizal fungi
associated with specific plants
penetrate plant root cells and provide soil nutrients in return for nutrients from plants
Chytrids
flagellated gametes
mobility
parasitic
Zygomycotes
bread/fruit moulds
soil fungi
Glomeromycetes
form symbiotic relationships with roots of land plants
example = mycorrhizal fungi
Basidiomycetes
club fungi, mushrooms, puffballs, bracket fungi
Ascomycetes
sac fungi, yeast, penicillin
Lichen
symbiotic relationship between an algae and a fungus
fungus provides support and encasement
algae provides photosynthetic products
Mitosis
cell division producing new cells for growth and repair
daughter cell is an exact clone of parent, same number of chromosomes
Meiosis
2 stage cell division producing sex cells (gametes) with half of the number of chromosomes as the parent
gametes are genetically different from parent cell and each other
Haploids and diploids
haploid = cell containing half the usual complement of chromosomes (n) diploid = cell containing two copies of each chromosome (2n)
Zygotes and embryos
zygote = cell formed by the fusion of two sex cells, they are diploid embryo = body of cells that develops after cell division occurs in zygote
Gametophytes and sporophytes
gametophyte = haploid organism that produces haploid sex cells sporophyte = diploid organism that produces haploid spores
Alternation of generations
alternation of generations = one complete life cycle
lifecycle for plants includes both a diploid and a haploid stage
Adaptation of plants
plants can’t physically migrate
to adapt from an aquatic environment they need:
structure to stay upright
conducting material for nutrients and waste
reproductive method that doesn’t include water
strategies for not losing water to environment
Anatomy of plants
rhizoids = hair-like structures, function like tiny roots
vascular tissue = xylem and phloem transport water and glucose solution
cuticle = layer of waxy noncellular tissue to provide waterproofing
stomata = pores in epidermis for gas exchange and water loss prevention
General characteristics of plants
eukaryotic, multicellular
use photosynthesis to produce food, autotrophic
cells walls containing cellulose
are a large source of oxygen for the planet
the basis for every terrestrial food web/chain
Bryophytes
successful and widespread
three divisions = mosses, hornworts, liverworts
no vascular tissue, therefore they depend on osmosis and diffusion to transport nutrients
no roots, instead root-like rhizoids
sporophyte grows out of gametophyte
need wet conditions, because they have no vascular tissue and the male gametes must swim
Pteridophytes
developed the vascular tissue that allowed them to grow tall
no flowers or seeds
simple roots and stems
sporophyte is independent from gametophyte
Seeds
seed plants are most recently evolved
seeds are plant embryos with a food supply (cotyledon) and a protective coating
Gymnosperms
disperse by means of seeds
reproduce sexually without needing water
consist only of seed, no surrounding fruit
includes cone-bearing trees, cycadophytes, gnetophytes, and ginkgophytes
gametes = female cones contain ovules, male cones produce pollen
Angiosperms
the most diverse grouping of plants
plants that protect their seeds within the body of a fruit
divided into monocots and dicots
sexual reproduction by pollination uses wind and animals as pollen carriers
gametes = female flowers contain eggs, male flowers produce pollen
Use of fruits
the fruit around the seeds helps with seed dispersal and growth
as fruit passes through a digestive tract, the seed coating is slowing weathered down
General characteristics of animals
eukaryotic, heterotrophic, multicellular
most are motile although some are sessile but can move during lifecycle
generally reproduce sexually, diploid stage of lifecycle dormant
Germ layers
germ layers give rise to specific tissues in the adult
ectoderm (outer layer) = skin, nervous tissue
endoderm (inner layer) = lining of the gut, respiratory system
mesoderm (middle layer) = circulatory, reproductive, excretory, muscular systems
Implication of germ layers
as organism complexity increases, a mesoderm appears
cells need to be serviced by a circulatory system as they aren’t in contact with the external environment
Body cavities
located between body wall and gut
contains and protects the internal organs
coelomate = mesoderm surrounds the cavity while the endoderm surrounds the gut (annelida)
acoelomate = only a lined gut, no cavity within the mesoderm (platyhelminthes)
pseudocoelomate = a fluid filled space, not as sophisticated as a true coelom (nematoda)
Body symmetry
radial symmetry = no defined head region, not suited to rapid locomotion
bilateral symmetry = a head region that can lead the organism
cephalization = the development of nervous tissue and feeding mechanisms in the head, integrates the activities of the nervous system, moves more efficiently
