Organism Development

Question 1

What are the two developments, and what are their basic stages?

Answer 1

Direct development: embryo to adult

Indirect development: embryo to larva to adult.

Question 2

What is spermatogenesis?

Answer 2

The formation of sperm. The spermatogonia produces primary spermatocytes via mitosis, which then further divide via meiosis until they become spermatozoa.

Question 3

Describe cleavage.

Answer 3

The rapid cell division after fertilization,

Question 4

What are the three types of fertilized eggs?

Answer 4

Mesolecithal, Telolecithal, and Isolecithal.

Question 5

Which types of animals have spiral cleavage?

Answer 5

Protostomes.

Question 6

Which types of animals have radial cleavage?

Answer 6

Deuterostomes.

Question 7

What is a blastula?

Answer 7

A many, many celled embryo with a hollow center.

Question 8

What process forms the germ layers?

Answer 8

Gastrulation.

Question 9

List five characteristics of Deuterostome development.

Answer 9

• radial cleavage
• regulative embryo
• blastopore becomes ass first, mouth second
• coelom forms by outpocketing (enterocoely)
• regulative development; cell fate is determined by interactions with neighboring cell

Question 10

List five characteristics of Protostome development.

Answer 10

• spiral cleavage
• mosaic embryo
• blastopore becomes mouth first, ass second
• coelom forms by splitting (schizocoely)
• mosaic development; cell fate is determined by the cytoplasm inherited during cleavage

Question 11

What are the two functional ways to make a coelom?

Answer 11

1. ) schizocoely (protostomes, forms by splitting)

2. ) enterocoely (deuterostomes, forms by outpocketing)

Question 12

What are the three germ layers possible?

Answer 12

The ectoderm (outer), mesoderm (middle), and endoderm (inner)

Question 13

What two main phylum are neither protostomes nor deuterostomes, and why are they not?

Answer 13

1. ) Porifera, because they have no true germ layers or tissues, as well as having no developmental symmetry.
2. ) Cnidaria, because they have radial symmetry (rather than bilateral symmetry).

Question 14

What two phyla are the only ones with radial symmetry?

Answer 14

Cnidaria and Echinodermata.

Question 15

What are the three main systems of birth?

Answer 15

oviparous: egg birth
lecithotrophic viviparity: keeping eggs in the body to grow
matrotrophic viviparity: nurturing offspring that is live at birth

Question 16

What is “parthenogenesis”?

Answer 16

Reproduction of females without males. Unisexual reproduction.

Question 17

What are the three defining characteristics of all in the Kingdom Animalia?

Answer 17

1. ) Multicellular
2. ) Heterotrophic
3. ) Eukaryotic

Question 18

What was the Cambrian Explosion, and how long ago was it?

Answer 18

The evolutionary event that gave rise to all major body plans that exist today. 600 mya.

Question 19

What are the four types of tissues?

Answer 19

• connective tissues
• nervous tissues
• epithelial tissues
• muscle tissues

Question 20

Tell me about epithelial tissues.

Answer 20

They cover surfaces (including the outside of the body as well as organs inside). They are classified by the number of layers present and the shape of their cells.

Question 21

Tell me about connective tissues.

Answer 21

They are widely spaces cells surrounded by an extracellular matrix. They can be loose (areolar) or dense. CT is found in cartilage, bone, and blood.

Question 22

Three types of muscle tissues:

Answer 22

• skeletal
• cardiac
• smooth

Question 23

Two cell types of nervous tissues:

Answer 23

• neurones

- glial cells

Question 24

From where does the coelom come from?

Answer 24

The mesoderm.

Question 25

What is the difference between a blind gut and a complete gut?

Answer 25

Blind gut has one opening (mouth), and the complete gut has two (mouth and anus).

Question 26

What is a pseudocoelomate?

Answer 26

An organism that has a “false” body cavity, or rather, a body cavity that functions regularly but lacks a mesodermal lining that wraps around. the gut.

Question 27

What is the general term for animals that have any number of body tissues and organs?

Answer 27

Metazoans.