Biology: The Dynamic Science

Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter 50

Animal Development - all with Video Answers

Educators

Chapter Questions

Problem 1

Major contributors to the axes of the animal body are the:
a. sperm and egg cytoplasm.
b. sperm and egg chromosomes.
c. ribosomes and mitochondria.
d. egg nucleus and yolk.
e. pigments.

Caroline Jones

Caroline Jones

Numerade Educator

Problem 2

The process by which cells undergo mitosis without a corresponding increase in cytoplasm is called:
a. polarity.
b. cleavage.
c. gastrulation.
d. organogenesis.
e. induction.

Caroline Jones

Numerade Educator

Problem 3

Which of the following mechanisms does not contribute to zygote development?
a. meiosis
b. mitosis
c. selective cell adhesions
d. determination
e. induction

Caroline Jones

Numerade Educator

Problem 4

A major event during gastrulation is:
a. the outward movement of cells at the dorsal lip of the blastopore.
b. the displacement of the archenteron by the blastocoel.
c. the formation of the coelom from the endoderm.
d. the extension of ectoderm and endoderm to form the yolk sac.
e. the development of ectoderm to form epidermal and neural tissues.

Caroline Jones

Numerade Educator

Problem 5

The presence of the gray crescent in a frog embryo:
a. corresponds to the location of the future mouth.
b. corresponds to the location of sperm entry into the egg.
c. will cause the formation of a disordered mass of cells.
d. contains concentrated amounts of darkly colored pigment granules from the animal pole.
e. indicates that the egg has been fertilized.

Caroline Jones

Numerade Educator

Problem 6

To contribute to the formation of a nervous system:
a. the neural crest develops into motor neurons.
b. the neural tube is converted into a neural plate.
c. the notochord induces the overlying ectoderm to become a neural plate.
d. the roof of the archenteron induces the formation of the neural tube.
e. somites give rise to the autonomic nervous system.

Caroline Jones

Numerade Educator

Problem 7

In mammalian development:
a. the morula develops into a trophoblast.
b. the chorionic villi allow the blastocyst to move down the oviduct.
c. the allantois takes over the work of the amnion.
d. the pharyngeal arches transform into the pharynx, larynx, and nasal cavities.
e. prolactin stimulates parturition.

Caroline Jones

Numerade Educator

Problem 8

In the development of the female sex organs:
a. all ducts in the 7-week embryo become Wolffian ducts.
b. the SRY gene is activated.
c. anti-Müllerian hormone is secreted.
d. the Müllerian ducts develop into oviducts.
e. the mother secretes oxytocin

Caroline Jones

Numerade Educator

Problem 9

In the embryonic development of the eye:
a. the optic vesicle cells permanently adhere to each other to prevent movement, whereas the optic cup cells are very motile.
b. signals from the optic cup trigger surface receptors on the lens placode.
c. gradients determine that the ectoderm overlying the lens vesicle develops into the optic vesicle.
d. microtubules powered by myosins and microfilaments powered by dyneins move the eye components around in the head region.
e. cadherins function in the presence of calcium to allow the lens placode and optic cup to break apart.

Caroline Jones

Numerade Educator

Problem 10

Which of the following statements about development is incorrect?
a. As microtubules lengthen and slide apart, the shape of cells within the ectoderm changes.
b. The extracellular matrix molecule fibronectin guides the movement of cells during development.
c. The furrow formed during mitosis of cells in the developing embryo is centrally located to ensure all cells divide symmetrically.
d. Cell surface cadherins regulate the ability of developing cells to adhere to one another.
e. Integrins are responsible for transmitting information from the extracellular matrix to the cytoskeleton.

Caroline Jones

Numerade Educator