Fungi, Animal Phyla, and Vertebrate Evolution: Key Concepts and Structures

What is the primary component of the cell wall in fungi?

Chitin

What is the fungal life cycle stage with two genetically different haploid nuclei in the same cell called?

Heterokaryon (or Dikaryon)

What is the mass of interwoven hyphae that constitutes the vegetative body of a fungus?

Mycelium

What is the fusion of two parent cytoplasm (but not nuclei) in the fungal sexual cycle called?

Plasmogamy

What is a plant root with a fungal partner that helps it absorb nutrients called?

Mycorrhizae

How do fungi obtain their nutrition?

Excreting enzymes outside their cells to digest their food.

What is the typical ploidy of the fruiting body (mushroom) of a Basidiomycete?

Dikaryotic ($n+n$)

Is the primary difference between Ascomycetes and Basidiomycetes in the structure that produces and holds the sexual spores?

True

What are the two characteristics unique to the Animal Kingdom (Metazoa)?

Presence of collagen and possession of nerve/muscle tissue.

Which phylum belongs to animals with no true tissues?

Porifera (Sponges)

What is the name of the hollow ball of cells formed after cleavage, but before gastrulation?

Blastula

In Deuterostomes, what does the blastopore develop into?

Anus

What are the genes responsible for controlling the development of major body axes and segment identity across animal phyla?

Homeotic genes (Hox genes)

What classification does an animal that is radially symmetric and lacks a mesoderm fall under?

Diploblast

Which of the following is NOT one of the four main defining characteristics of the phylum Chordata?

Ventral solid nerve cord

Are jawless fishes like Lampreys and Hagfish the earliest-diverging lineage of vertebrates?

True

What major evolutionary innovation allowed tetrapods to complete their life cycle entirely on land?

The Amniotic Egg

Which group of vertebrates includes the first animals to have developed limbs capable of walking on land?

Amphibians

Which group of fish is most closely related to all terrestrial vertebrates (Tetrapods)?

Lobe-finned fishes

Which ectothermic amniotes possess keratinized scales to resist desiccation?

Reptiles

Which invertebrates are phylogenetically closest to vertebrates?

Echinoderms

What is the distinguishing feature of Monotremes compared to other mammals?

They lay eggs.

What major ecological role do fungi play that makes them essential to ecosystems?

They are primary decomposers, breaking down complex organic material like cellulose and lignin.

Why are molds (like Penicillium) considered imperfect fungi (Deuteromycetes)?

Because their sexual (meiotic) stage was not known at the time of their classification; they only reproduced asexually.

Fungi store their excess carbohydrate energy as what?

Glycogen.

What is a haustorium?

A specialized hypha that allows parasitic fungi to penetrate the tissues of their host cell and absorb nutrients.

What is the term for the fusion of the two haploid nuclei in the fungal sexual cycle?

Karyogamy.

What is the difference between indeterminate cleavage and determinate cleavage in early embryonic development?

Indeterminate: Each early cell retains the potential to develop into a complete embryo (Deuterostomes). Determinate: The developmental fate of each blastomere is fixed early; separated cells cannot form a complete embryo (Protostomes).

What does a lack of a true coelom imply about an animal?

It is either Acoelomate (like flatworms) or Pseudocoelomate (like roundworms), belonging to one of the earliest diverging Bilaterian lineages.

What is the significance of a dorsal hollow nerve cord in chordates?

It runs along the back (dorsal side) and is hollow, differentiating it from the solid, ventral nerve cord of protostomes.

Match the Animal Group with its defining characteristic: Mollusca, Arthropoda, Cnidaria.

Mollusca: Mantle/Visceral Mass; Arthropoda: Jointed Appendages; Cnidaria: Nematocysts (Stinging Cells).

The evolution of jaws in vertebrates is linked to the modification of which structure?

Skeletal elements that previously supported the pharyngeal slits (gill arches).

What is the specific function of the allantois membrane in an amniotic egg?

It acts as a disposal sac for metabolic wastes (like uric acid).

What is the primary method used by ectothermic animals to regulate their body temperature?

Using external heat sources (like the sun) and behavior (basking, seeking shade).

Match the Mammal Group with its reproductive strategy: Placental Mammals, Marsupials, Monotremes.

Placental Mammals: Long gestation period with complex placenta; Marsupials: Young complete development in an external pouch; Monotremes: Lay hard-shelled eggs.

The earliest vertebrates lacked which of the following?

Jaws.

Birds (Aves) are considered part of which larger reptile lineage?

Diapsids (specifically within the archosaurs, alongside crocodiles).