Biology 210 Lecture Exam 3 Study Guide

These flashcards cover key concepts from Development, Integument, and provide a foundation for the upcoming exam.

What processes occur when sperm fertilizes the egg, and what prevents multiple sperm from fertilizing the egg?

Sperm injects genetic material into the egg, leading to the formation of a zygote, while mechanisms like the fast block and slow block prevent polyspermy.

Why is yolk important in development?

Yolk provides essential nutrients for the developing embryo.

What are the different yolk classifications and their impact on cleavage?

Yolk can be classified as isolecithal, mesolecithal, or telolecithal, affecting cleavage patterns (e.g., complete vs. incomplete cleavage).

What is the difference between radial and spiral cleavage?

Radial cleavage results in cells aligned directly above each other, while spiral cleavage results in cells being offset.

What is blastulation, and what is the blastocoel?

Blastulation is the process of forming a blastula, which contains a fluid-filled cavity called the blastocoel.

What is gastrulation, and how does it relate to the ectoderm and endoderm germ layers?

Gastrulation is the process that forms the three germ layers: ectoderm, mesoderm, and endoderm.

What does it mean to be diploblastic versus triploblastic?

Diploblastic organisms have two germ layers (ectoderm and endoderm), while triploblastic organisms have three layers (ectoderm, mesoderm, and endoderm).

What is the difference between schizocoely and enterocoely origins of the coelom?

Schizocoely forms from mesoderm splitting, while enterocoely forms from pouches of the archenteron.

Define acoelomate, pseudocoelomate, and coelomate. Provide examples of each.

Acoelomate organisms lack a body cavity (e.g., flatworms); pseudocoelomates have a body cavity not entirely lined by mesoderm (e.g., roundworms); coelomates have a true coelom (e.g., annelids).

What characteristics distinguish protostomes from deuterostomes?

Protostomes have determinate cleavage, while deuterostomes have indeterminate cleavage and the coelom forms from the archenteron.

What are the 4 extraembryonic membranes and their functions in amniotes?

The amnion (protection), chorion (gas exchange), allantois (waste storage), and yolk sac (nutrient transfer).

What are the differences among monotremes, marsupials, and placental mammals?

Monotremes lay eggs, marsupials have a pouch for young; placental mammals carry young in the uterus.

What is integument, and what is its function?

Itegument refers to the skin and its derivatives, protecting internal structures and regulating temperature.

Why doesn’t Phylum Porifera have an actual epidermis?

Porifera lacks true tissue layers; instead, they have a unique structure with cellular layers called choanocytes and mesohyl.

What are unique cells or characteristics of invertebrates in their integument?

Invertebrates may have unique cells like cnidocytes (stinging cells) that aid in defense and feeding.

What is a true exoskeleton, and what organisms possess it?

A true exoskeleton is a hard outer structure found in arthropods, formed by chitin.

What are the two different ways that the cuticle can harden?

The cuticle can harden through sclerotization (hardening through cross-linking of proteins) or calcification (incorporating minerals like calcium).

What kinds of cells contribute to the coloration of integument?

Chromatophores and melanocytes contribute to coloration; chromatophores change color for camouflage, while melanocytes provide pigmentation.

What tissue types make up the epidermis and dermis of a vertebrate?

The epidermis is primarily made of epithelial tissue, while the dermis is composed of connective tissue.

How is the epidermis of amphibians different from that of reptiles?

Amphibian epidermis is generally thinner and more permeable, allowing for gas exchange, while reptile epidermis is thicker and keratinized for protection.

Who has scales, and where do they originate from?

Scales are found in reptiles and fish, originating from dermal layers or epidermal tissues.

What are the different types of feathers and their functions?

Contour feathers for temperature regulation and flight, down feathers for insulation, and flight feathers for lift.

What unique epidermal characteristics do mammals possess?

Mammals have hair and mammary glands, which are not found in other taxa.

What are some different functions of glands in integument?

Glands can provide lubrication, secretion of pheromones, or defensive compounds.

What are the differences between horns and antlers?

Horns are permanent structures covered in keratin, while antlers are shed annually and are made of bone.