Final Practice Test
D → The body plan associated with having only two embryonic germ layers is diploblastic
B → Animals are multicellular heterotrophs that ingest their food
D → Animals are unicellular during the early stages of development, which distinguishes their multicellularity from that of other eukaryotic kingdoms
3 is B, Animals multicellularity can be distinguished from that of other eukaryotic kingdoms because animals have specialized cells that lack cell walls and are connected by unique structural proteins.
C → The statement about the evolution of animal body plans that is most supported by current phylogenic evidence is: the development of tissues and bilateral symmetry are linked to more complex behaviour and movement patterns
D → Compared to the cambrian explosion, the Ediacaran biota lacks definitive example of bilateral symmetry, limiting movement
B → Sponge don’t have true tissue because they’re not eumetazoan
D → Their lack of tissue organization allows cells to function independently, since they don’t have true tissues, their cells are more independent and flexible, and can reorganize
A → Their tentacles contain cnidocytes that can immobilize prey
B → The presence of both medusa and pylop stages in meduzoans allows them to alternate between sessile and free-living forms for reproduction and dispersal
A → Nematoda is not a Lophotrochozoa phylum, it is part of Edcysozoa (Phylum Arthropods and Phylum Nematodes (roundworms)
A → The evolutionary trade-off associated with the flat shape of Platyhelmnthes (flatworms, part of Lophotrochozoans) is that they have increased surface are for. gas exchange but reduced cultural support
B → The feature that supports the classification of this species within Lophotrochozoa is spiral and determinate cleavahe during embryonic development
E → The primary role of a snail (not-vertebrate) host during the lifecycle of a parasitic trematode is to act as an intermediate host for larval development and asexual reproduction
E → The radula was lost due to adaptation to a filter-feeding lifestyle. Filter-feeding molluscs like bivalves (e.g. clams, mussels) don’t need a radula because they strain food particles from water instead of scraping or cutting food.
C → Ecdysis, they shed, which enables ecdysozoans (arthropods and nematodes) to grow despite their rigid cuticle
E → Nematode species decomposes organic matter in agricultural soil, enhancing soil fertility
E → Hexapods (ants, beetles, butterflies) have uniramous legs, while crustaceans (crabs, shrimp, lobster) typically have biramous appendages
C → Chelicerates (like spiders, scorpions, and mites) have a body divided into two main regions: the cephalothorax(which combines the head and thorax) and the abdomen. Myriapods (like millipedes and centipedes) have a body divided into a head and a segmented trunk (which is made up of many body segments).
B → Arthropod exoskeletons are composed of chitin which provides a rigi structure for movement while remaining lightweight
B → Chelicerae reflect adapations to Chelicerates lifestyle because they are modified for defence and feeding, with vatiations across species
A → The presence of biramous appendahes indicates an aquatic origin where one branch is specialized for locomotion and the other for gas exchange in the evolutionary history of crustaceans
B → Presence of uniramous appendages supports the terrestrial success of insects
22 is C, the presence of a traecheal system for direct oxygen delivery to tissues support insects adaption to their terrestrial success
C → Low light levels and a need for sensory enhancement let to long antennae and unpigmented biomineralized exoskeleton
A → Millepedes have venomous claws for predatation, while centipedes lack them
24 is C, millipedes are herbivorous and have two pairs of legs per segment, while centipedes are carnivorous with one pair per segment
B → Increased dispersal pottential and acces to diverse niches (3 diff. tagmata and specialized wings)
B → Pentaradial symmetry (they’re radial, only bilateral as larvae)
A → Ossicles present in echinoderms suggest that they evolved independently of other deutersomes
27 is C, Ossicles present in echinoderms provides detailed insight into the morphological. adaptations of extinct species
D → vertebral column supports the attachment of complex systems for locomotion
E → Tunicates are sessile as adults, while lancelets retain mobility
D → It relied heavily on filter feeding in aquatic ecosystems
D → Cyclostomes: jawless vertebrates, which include hagfishes and lampreys. They’re considered basal (primitive) vertebrates because they don’t have jaws like the more derived groups (gnathostomes)
D → Gnathostomes (jaws), they have minilerized skeletal elements
E → Jaws in gnathostomes enable the consumption of larger and more diverse prey
E → Rasping toungue with mineralized projections, Lampreys use their rasping tongue—lined with keratinized (mineral-like) projections—to latch onto prey and scrape tissue. That’s what supports their feeding and attachment behavior.
34 is A, A cartilaginous skeleton with a reinforced oral disc is a key morphological feature that supports Lampreys use of their oral sucker to attach to rocks or prey.
C → paired fins means enganced maneuverability and stability while swimming
B → Endoskeletal bones provide internal support, while dermal bones form protective external structures
A → The presence of a cartilaginous skeleton without ossification Chondrichthyans (like sharks, rays, and skates) have cartilage-based skeletons that don’t ossify like the bones of bony fish (Osteichthyans)
C → Chondrichthyans
D → Provide neutral boyancy
E → It indicates that Actinopterygii includes all descendants of a common ancestor (because that’s what a monphyletic group is)
A → mammary glands that produce mlk
B → Laying leathery-shelled eggs similar to reptiles. Monotremes (like the platypus and echidna) are wild because they lay eggs—just like reptiles—which shows how ancient and basal they are on the mammal family tree.
E → A shorter and wider pelvis supports upright posture and balances weight distribution is associated with development of bipedal locomotion
C → Bipedal locomotion was evolved first in hominins
E → It reduces energy expenditure during locomotion. A more aligned foot in australopiths helped them walk efficiently on two legs, reducing the energy needed for bipedal movement. This made long-distance walking or running easier and more sustainable
D → Increased brain size and tool use
C → Higher incidence of back, hip, and leg joint strai
A. 3, 2, 1, 4
Development of bipedalism
Migration out of Africa
Expansion of cranial capacity beyond 1,200 cc
Appearance of Homo sapiens