🧬 BASIC ANIMAL / DEVELOPMENT / EVOLUTION LEC 3 ANSWERS

Animal cells have cell walls.

False

Bilateral symmetry allows directional movement.

True

The ectoderm forms

Nervous system

Indeterminate cleavage allows:

 Identical twins

What characterizes the Eumetazoa

True differentiated tissues

Ecdysozoa are characterized by

Molting

In deuterostome development, what happens to the blastopore?

It becomes the anus

Parthenogenesis produces:

 Offspring from unfertilized eggs

What defines a diploblastic organism?

 Development from two germ layers

What was Anomalocaris?

A large predatory arthropod-like creature of the Cambrian period

The primary function of lacunae in bone tissue is to:

House osteocytes

In terms of energy efficiency, endotherms:

Use more energy for temperature regulation

During hibernation, an animal's

Metabolic rate decreases significantly

Apodemes in arthropods are most similar to

Tendons

In homeostatic regulation, a set point is:

The optimal value around which a variable is maintained

Loose connective tissue is characterized by:

Scattered fibers and cells in a matrix

Countercurrent heat exchange:

Warm arterial blood heats cooler venous blood

Muscle tissue with intercalated discs

Cardiac muscle

Nematode outer layer contains

Chitin and collagen

Anthozoa characteristics:

They exist only as polyps

Cnidarian gastrovascular cavity function

Both digestion and circulation

Sponge skeletal elements are called

Spicules

Flatworms are classified as

 Acoelomates

Cnidarian body forms are

 Polyp and medusa

Nematode symmetry

Bilateral

Which characteristic is NOT shared by all chordates

Vertebral column

Mollusk class with most developed nervous system

Cephalopoda

Clitellum in oligochaetes is

A reproductive structure

Chelicerates lack

Antennae

Mantle in mollusks functions in

Shell secretion

Cephalopods are distinguished by

Closed circulatory system

Deuterostomes are characterized by

 Anus forming from blastopore

Ecdysozoa are defined by

Chitinous cuticle that must be molted

Annelid segments are separated by

Septa

Bivalves lack

Radula

Cnidarians have

 Radial symmetry + stinging cells (cnidocytes)

Sponges (Porifera) are

Asymmetrical, no true tissues

Cnidarian stinging cells are called

Cnidocytes (contain nematocysts)

Sponges are filter feeders using

Choanocytes

Flatworms have what digestive system?

Incomplete digestive system (gastrovascular cavity)

Rotifers belong to which group?

Lophotrochozoa (protostomes)