Chapter 47 Animal Development

Question 1

What is fertilization?

Answer 1

Formation of a diploid zygote from a haploid egg and sperm

Question 2

What two stages initiates embryonic development?

Answer 2

• fertilization
• cleavage

Question 3

What is acrosomal reaction?

Answer 3

The triggering of when the sperm meets the egg

Question 4

What is the acrosome?

Answer 4

Tip of the sperm head that releases hydrolytic enzymes to fertilize the egg

Question 5

What is a fast block to polysperm?

Answer 5

a process that prevents additional sperm from entering an egg after the first sperm fertilizes it

Question 6

What is the slow block to polysperm?

Answer 6

a process that prevents multiple sperm from fertilizing an egg by releasing material from the egg that creates a physical barrier to further sperm

Question 7

What initiates the cortical reaction?

Answer 7

The fusion of the egg and sperm

Question 8

What starts egg activation?

Answer 8

Increase in calcium in the cytosol –> increases the rates of cellular respiration and protein synthesis by the cell

Question 9

What is the zona pellucida?

Answer 9

Extracellular matrix of the egg

Question 10

Is fertilization in mammals and other terrestrial animals, internal or external?

Answer 10

Internal

Question 11

What is cleavage?

Answer 11

A period of rapid cell division without growth

Question 12

What are blastomeres?

Answer 12

The cytoplasm of one large cell that is split into many smaller cells

Question 13

What is the blastula?

Answer 13

A ball of cells with a fluid-filled cavity

Question 14

What is a blastocoel?

Answer 14

The fluid-filled cavity in the blastula

Question 15

What is morphogenesis?

Answer 15

Process by which cells occupy their appropriate locations

Question 16

What is involved with morphogenesis? (2)

Answer 16

• Gastrulation
• Organogenesis

Question 17

What is gastrulation?

Answer 17

Movement of cells from the blastula surface to the interior of the embryo

Question 18

What is organogenesis?

Answer 18

Formation of organs

Question 19

What is the gastrula?

Answer 19

A three layered embryo that was originally the cells of the blastula

• rearranged by gastrulation

Question 20

What are the 3 layers of the gastrula?

Answer 20

1. ectoderm
2. endoderm
3. mesoderm

Question 21

What does the ectoderm form?

Answer 21

Forms the outer layer

Question 22

What does the endoderm outline?

Answer 22

Outlines the digestive tract

Question 23

What does the mesoderm do?

Answer 23

Partially fills the space b/w the endoderm and the ectoderm

Question 24

What is the blastocyst?

Answer 24

Human equivalent to the blastula

Question 25

What is the inner cell mass?

Answer 25

Cluster of cells at one end of the blastocyst

Question 26

What is the trophoblast?

Answer 26

Outer epithelial layer of the blastocyst and does not contribute to the embryo, but instead initiates implantation

Question 27

What are amniotes?

Answer 27

Embryos that are surrounded by fluid in a sac called the amnion

Question 28

What are the 4 extraembryonic membranes that form around the embryo?

Answer 28

1. Chorion --> function in gas exchange 2. Amnion --> Encloses amniotic fluid 3. Yolk sac --> Encloses yolk 4. Allantois --> Disposes of waste products and contributes to gas exchange

Question 29

What begins neurulation?

Answer 29

The cell formation from the dorsal mesoderm that forms the notochord

Question 30

What is the notochord?

Answer 30

A rod extending along the dorsal side of the embryo

Question 31

What is induction?

Answer 31

When cells or tissues cause a developmental change in nearby cells

Question 32

What is the nerual tube?

Answer 32

When a neural plate curves inward

Question 33

What do neural crest cells develop into?

Answer 33

Found along the neural tube of vertebrates, it develops into various parts of the embryo

Question 34

What is apoptosis?

Answer 34

Programmed cell death

Question 35

What is determination?

Answer 35

Used to describe the process by which a cell or group of cells become committed to a particular fate

Question 36

What is differentiation?

Answer 36

Refers to the resulting specialization in structure and function

Question 37

What are fate maps?

Answer 37

Diagrams that show organs and other structures that arise from each region of the embryo

Question 38

What is pattern formation?

Answer 38

Development of spatial organization