ex3 Flashcards
What are the main structures of fungi?
Mycelia and Hyphae.
What is the difference between septate and coenocytic hyphae?
Septate hyphae have cross-walls (septa) while coenocytic hyphae do not.
What is chitin?
A structural polysaccharide that makes up the cell walls of fungi.
What are mycorrhizae?
Symbiotic associations between fungi and plant roots, which can be ectomycorrhizal or arbuscular.
What is a haustorium?
A specialized structure used by fungi to penetrate host tissues.
What are plasmogamy and karyogamy?
Plasmogamy is the fusion of cytoplasm from two parent mycelia, while karyogamy is the fusion of their nuclei.
What is the ploidy of key fungal structures?
Plasmogamy results in a heterokaryotic phase
Karyogamy results in a transient diploid phase before undergoing meiosis and becoming haploid
zoopagomycetes?
A group of fungi that includes parasites and saprobes.
Zygosporangia?
Structures formed during the sexual reproduction of zygomycetes.
ascomycetes?
A group of fungi characterized by the formation of ascospores in an ascus.
Ascocarp?
The fruiting body of ascomycetes that contains the asci.
Basidiomycetes?
A group of fungi that produce basidiospores on a basidium.
Lichen?
A symbiotic relationship between fungi and photosynthetic organisms, typically algae or cyanobacteria.
What are the stages of early embryonic development?
Cleavage, Blastula, Gastrula, with structures like the archenteron, blastopore, and blastocoel.
What is the difference between protostomes and deuterostomes?
Protostomes develop the mouth first, while deuterostomes develop the anus first.
What is the significance of indeterminate vs. determinate cleavage?
Indeterminate cleavage allows for identical twins, while determinate cleavage results in specific cell fates.
What are the characteristics of bilateria?
Bilateral symmetry and cephalization.
Cephalization
concentration of sense organs and nerves
What are diploblastic and triploblastic organisms?
Diploblastic organisms have two germ layers (ectoderm and endoderm), while triploblastic organisms have three (ectoderm, mesoderm, endoderm).
What are coelomates, pseudocoelomates, and acoelomates?
Coelomates have a true coelom, pseudocoelomates have a body cavity that is not entirely lined with mesoderm, and acoelomates lack a body cavity.
What are the two major groups of protostomes?
Ecdysozoa and Lophotrochozoa.
What is a lophophore?
A feeding structure found in some lophotrochozoans.
What are metazoans and eumetazoans?
Metazoans are multicellular animals, while eumetazoans are a subgroup that includes all animals except sponges.
What are the main features of sponges (Porifera)?
They have an osculum, choanocytes, amoebocytes, mesohyl, and spicules.
What are the main classes of Cnidaria?
Anthozoa and Medusazoa (Hydrozoa, Cubozoa, and Scyphozoa)
What are cnidocytes and nematocysts?
Cnidocytes are specialized cells in cnidarians that contain nematocysts, which are stinging structures.
What are the main characteristics of Platyhelminthes?
They are flatworms with structures like protonephridia, eyespots and a pharynx.
Protonephridia
excretory tubes that lack internal openings
What are the reproductive strategies of rotifers?
They can reproduce through parthenogenesis and have complex life cycles.
Parthenogenesis
asexual reproduction in which an egg can become fertilized without the need for sperm
What are the four classes of Molluscs?
Polyplacophora, Gastropoda, Bivalvia, and Cephalopoda.
What are the main body parts of molluscs?
Foot, visceral mass, mantle, radula, and torsion.
What are the main groups of Annelids?
Errantians and Sedentarians.
What is a closed circulatory system?
A system where blood is contained within vessels.
What are chaetae and parapodia?
Chaetae are bristle-like structures, while parapodia are lateral extensions used for movement.
What are the main groups of Arthropods?
Cheliceriformes, Myriapods, Hexapods, and Crustaceans.
What is hemolymph?
The fluid equivalent to blood in arthropods.
What are book lungs?
Respiratory structures found in some arachnids.
What are chelicerae?
The mouthparts of chelicerates, often modified into fangs.
What are mandibles?
Jaw-like structures found in some arthropods.
What is the difference between incomplete and complete metamorphosis?
Incomplete metamorphosis involves gradual changes, while complete metamorphosis includes distinct larval stages.
What is metamorphosis?
A biological process involving a significant change in form or structure during an organism’s development.
What are Echinoderms?
A group of marine animals characterized by a water vascular system and tube feet.
What is the water vascular system in Echinoderms?
A network of hydraulic canals used for locomotion, feeding, and gas exchange.
What are tube feet?
Extensions of the water vascular system in Echinoderms used for movement and feeding.
What are fungi?
Heterotrophic organisms that feed via absorption, essential for terrestrial ecosystems.
How do fungi contribute to ecosystems?
They break down organic material and recycle vital nutrients, acting as decomposers, mutualists, and parasites.
What is mycelia in fungi?
Networks of branched hyphae that facilitate absorption.
What are hyphae?
Filaments that make up mycelia, releasing enzymes and absorbing nutrients.
What are the cell walls of fungi composed of?
Chitin.
What are predatory hyphae?
Hyphae that rapidly constrict and penetrate prey, such as nematodes.
What are haustoria?
Specialized hyphae that penetrate the tissues of their host, commonly found in parasitic fungi.
What is the relationship between Arbuscular Mycorrhizal Fungi and plants?
A mutually beneficial relationship where fungi extend hyphae into plant root cells.
What do ectomycorrhizal fungi do?
They form sheaths of hyphae around roots and grow into extracellular spaces of root cortex.
What is the difference between septate and coenocytic hyphae?
Septate hyphae have cells separated by internal walls (septa), while coenocytic hyphae lack septa and form a continuous multinucleated cell.
How do fungi reproduce?
By producing a large number of spores either sexually or asexually.
What is plasmogamy in fungi?
The fusion of the cytoplasm of two parent cells, resulting in a heterokaryotic phase.
What is karyogamy?
The fusion of two haploid nuclei to form a DIPLOID nucleus, occurring after plasmogamy.
How do molds reproduce asexually?
By producing haploid spores through mitosis and forming visible mycelia.
How do yeasts reproduce asexually?
By cell division and the pinching off of ‘bud’ cells from a parent cell.
What are deuteromycetes?
Imperfect fungi that have no known sexual stage and are reassigned when sexual stages are discovered.
What are Cryptomycota?
A diverse group of basal fungal taxa found in various environments, often appearing parasitic.
What are microsporidians?
Unicellular parasites of animals with a chitin-rich cell wall and reduced mitochondria.
What are chytrids?
Fungi found in various habitats that can be decomposers, parasites, or mutualists, characterized by flagellated spores.
What are mucoromycetes?
Fast-growing molds and parasites that form mutualistic relationships with many plant species.
What are Ascomycetes known for?
They include plant pathogens, decomposers, and symbionts, with over 25% as lichens.
In what types of habitats do Ascomycetes live?
They live in marine, freshwater, and terrestrial habitats.
How are Ascomycetes defined?
They are defined by the production of sexual spores in asci, usually contained in ascocarps.
What is the method of asexual reproduction in Ascomycetes?
They reproduce asexually by producing enormous numbers of asexual spores called conidia.
What are conidiophores?
Conidiophores are specialized hyphal branches of fungi that produce conidia.
What is Neurospora and why is it significant?
Neurospora is a model organism with a well-studied genome.
What types of fungi are included in Basidiomycetes?
Basidiomycetes include mushrooms, puffballs, shelf fungi, mutualists, and plant parasites.
What is a key feature of the Basidiomycetes life cycle?
It usually includes a long-lived DIKARYOTIC mycelium.
What happens during the life cycle of Basidiomycetes in response to environmental stimuli?
The mycelium reproduces sexually by producing elaborate basidiocarps.
What are basidiocarps?
Basidiocarps are elaborate fruiting bodies produced by Basidiomycetes.
What are basidia in a basidiocarp?
Sources of sexual spores called basidiospores.
What is a basidium?
A club-like structure that is a transient diploid stage in the life cycle of fungi.
What are club fungi?
Fungi that are characterized by the presence of basidia.
How do some fungi assist animals?
They help break down plant material in the guts of cows and other grazing animals.
What role do ants and termites play in relation to fungi?
They raise fungi in farms for digestive services.
What is lichen?
A symbiotic association between a photosynthetic microorganism and a fungus.
What is the fungal component of lichen usually classified as?
An ascomycete.
What do algae and cyanobacteria provide in a lichen?
Algae provide carbon, while cyanobacteria provide organic nitrogen.
How do fungi contribute to the growth of algae and cyanobacteria in lichen?
Fungi provide an environment for growth.
What is asexual reproduction in lichens performed by?
Fragmentation or formation of soredia.
Soredia?
Small clusters of hyphae with embedded algae.
Why are lichens considered important pioneers?
They are the first biological components to reach new rock and soil.
How do lichens serve as indicators of environmental health?
They are sensitive to pollution, making them good metrics for measuring air quality.
What are the characteristics of animals?
Animals are multicellular, heterotrophic eukaryotes that lack cell walls.
What structural protein holds animal bodies together?
Collagen.
What are tissues in animals?
Groups of similar cells organized to act as a unit.
What types of tissue are unique to animals?
Nervous tissue and muscle tissue.
What is the dominant stage in the animal life cycle?
The diploid stage.
How are haploid sperm and egg cells produced?
By mitotic cell division.
What is cleavage in embryonic development?
Rapid, early cell divisions of a zygote that transform it into a multicellular embryo.
What is a blastula?
A hollow ball of cells surrounding a fluid-filled cavity (blastocoel).
What occurs during gastrulation?
The blastula transforms into a gastrula with different layers of embryonic tissue.
What is a larva?
A sexually immature stage that is morphologically distinct from the adult.
What are Hox genes?
Genes found in all and only animals that regulate the development of body plan.
What significance do Hox genes have in evolution?
They are highly conserved and can produce a wide diversity of animal morphology.
What is the estimated history span of animals?
More than 500 million years.
How many extant animal species have been identified?
1.3 million.
What evidence supports the origin of sponges?
710 million-year-old sediment containing chemical evidence of steroids known to be produced by sponges.
What do molecular clock studies examine?
Neutral regions of DNA to determine the rate of mutation.
What can be inferred about the age of a lineage of organisms by examining mutations?
The approximate age can be determined by examining the number of mutations between groups of organisms.
What evidence supports choanoflagellates as the closest living relatives to animals?
Morphological and molecular evidence supports this relationship.
What are choanoflagellates?
Single-celled, flagellated eukaryotes.
What is a significant similarity between collar cells of sponges and choanoflagellates?
They are nearly indistinguishable from each other.
What role do cadherin attachment proteins play in sponges?
They are involved in the adhesion of cells.
What is the CCD domain?
A highly conserved region found in animals but not in choanoflagellates.
What major geological era marks the oldest macroscopic fossils of animals?
Neoproterozoic Era (1B - 541 MA).
What significant event occurred during the Paleozoic Era?
The Cambrian explosion (535-525 MA), marking the appearance of the oldest fossils for half of all extant animal phyla.
What are the two main types of symmetry used to categorize organisms?
Radial symmetry and bilateral symmetry.
What does cephalization refer to in animal development?
The development of a head.
What are the three germ layers in animal embryos?
Ectoderm, endoderm, and mesoderm.
What distinguishes diploblastic organisms from triploblastic organisms?
Diploblastic organisms have two tissue layers (ectoderm and endoderm), while triploblastic organisms have three layers, including mesoderm.
What is a coelom?
A true body cavity derived from mesoderm.
What are the three categories of body cavity types in animals?
Eucoelomates (true body cavity), pseudocoelomates (derived from mesoderm and endoderm), and acoelomates (lack a body cavity).
How does protostome development differ from deuterostome development?
In protostomes, the blastopore becomes the mouth; in deuterostomes, it becomes the anus.
What is the significance of cleavage patterns in embryonic development?
Protostome cleavage is spiral and DETERMINATE, while deuterostome cleavage is radial and INDETERMINATE.
What percentage of animal species are invertebrates?
Invertebrates account for 95% of animal species.
What are the three major clades of Bilateria?
Deuterostomia, Lophotrochozoa, and Ecdysozoa.
What is the basic body plan of cnidarians?
A sac with a central digestive compartment (gastrovascular cavity).
What are nematocysts?
Specialized organelles within cnidocytes that eject a stinging thread.
What distinguishes the two variations of cnidarian body plans?
Polyp is sessile, while medusa is motile.
What are the characteristics of flatworms (Platyhelminthes)?
Triploblastic development, acoelomates, and flattened dorsoventrally.
What is the function of protonephridia in flatworms?
Regulates osmotic balance ; faux excretory organs
What is the life cycle characteristic of flukes?
They have complex life cycles with alternating sexual and asexual stages and require multiple hosts.
What is the primary mode of nutrition for tapeworms?
They absorb nutrients from their host’s intestines.
What environments do rotifers inhabit?
Freshwater, ocean, and damp soil.
What are the characteristics of species smaller than protists that are multicellular?
They have specialized organ systems and are triploblastic.
What is an alimentary canal?
A digestive tube with a separate mouth and anus that lies within a fluid-filled pseudocoelom.
How do some species reproduce without males?
Through parthenogenesis, where females produce offspring from unfertilized eggs.
What is a lophophore?
A horseshoe-shaped suspension-feeding organ with ciliated tentacles.
What are ectoprocts?
Colonial animals that superficially resemble moss and have a hard exoskeleton encasing the colony.
What are brachiopods and how do they differ from clams?
Brachiopods superficially resemble clams, but their two shell halves are dorsal and ventral, rather than lateral.
What are the main groups included in the phylum Mollusca?
Snails, slugs, oysters, clams, octopuses, and squids.
What are the three main parts of a mollusk’s body plan?
Muscular foot, visceral mass, and mantle.
What is a radula?
A rasp-like structure used by many mollusks to scrape food off surfaces.
What is a trochophore?
A ciliated larval stage in the life cycle of many mollusks.
What distinguishes gastropods from other mollusks?
Gastropods, which make up ¾ of molluscs, often have a single spiraled shell and experience torsion.
What is torsion in gastropods?
A process that causes the anus and mantle to end up above the head.
What are the main characteristics of cephalopods?
They are carnivores with beak-like jaws, tentacles, a closed circulatory system, and well-developed sense organs.
What is the significance of ammonites in paleontology?
Ammonites were common shelled cephalopods prior to their extinction at the end of the Cretaceous.
What are the two clades of annelids?
Errantians, which are highly mobile, and Sedentarians, which tend to be less mobile.
How do earthworms reproduce?
They are hermaphrodites but typically cross-fertilize.
What is hirudin?
A chemical secreted by leeches to prevent blood from coagulating.
What is ecdysis?
The process of shedding or molting the cuticle in ecdysozoans.
What are the two largest phyla in Ecdysozoa?
Nematodes and arthropods.
What are nematodes and where can they be found?
Nematodes are found in most aquatic habitats, soil, and tissues of plants, and they contain an alimentary canal but lack a circulatory system.
What are the main features of arthropods?
Segmented body, hard exoskeleton, paired jointed appendages, and an open circulatory system.
What are the three major lineages of living arthropods?
Chelicerates, myriapods, and pancrustaceans.
What are chelicerates?
A lineage of arthropods that includes sea spiders, horseshoe crabs, scorpions, ticks, mites, and spiders, characterized by claw-like feeding appendages.
What distinguishes myriapods?
They are terrestrial arthropods with jaw-like mandibles, including centipedes and millipedes.
What is the significance of flight in insects?
Flight allows insects to escape predators, find food, and disperse to new habitats.
What are the two types of metamorphosis in insects?
Incomplete metamorphosis, where young nymphs resemble adults, and complete metamorphosis, where larvae look entirely different from adults.
What are echinoderms and their key features?
Echinoderms are slow-moving and sessile marine animals with a water vascular system and an endoskeleton of hard calcareous plates.
What are the five clades of echinoderms?
Asteroidea (sea stars), Ophiuroidea (brittle stars), Echinoidea (sea urchins), Crinoidea (sea lilies), and Holothuroidea (sea cucumbers).
What are the two basal groups of chordates?
Lancelets and tunicates, along with hagfishes and vertebrates.
