Taxonomy

Question 0

The cell

Answer 0

Basic unit of all forms of life

Question 1

Three domains

Answer 1

Bacteria
Archaea
Eukarya

Question 2

A tissue

Answer 2

A group of similar cells that perform a particular action

Question 3

An organ

Answer 3

Group of tissues that work together to perform related functions

Question 4

Dipoblastic animals

Answer 4

Have ectoderm, endoderm and mesoglea (instead of mesoderm), that holds the two layers together

Question 5

Tripoblastic animals

Answer 5

Have all three layers (ectoderm, endoderm and mesoderm);

Are more complex

Question 6

Cephalization

Answer 6

• development of the head
• comes along with bilateral symmetry
• simple animals (sponges, cnidarians) do not have a head

Question 7

Coelom

Answer 7

Fluid-filed body cavity that is completely surrounded by mesoderm

Provides space for elaborate organ systems

Question 8

Acoelomates

Answer 8

Do not have coelom

E.g. Flatworms

Question 9

Pseudocoealomates

Answer 9

Have a fluid filled tube between the endoderm and mesoderm, but not completely lined by mesoderm;

Nematodes, roundworms

Question 10

Coelom ages

Answer 10

Have coelom, are the most complex

Include: Annelida, Mollusca, Arthropoda, Chordata

Question 11

9 animal Phyla to know:

From the simplest to the most complex

Answer 11

1) Porifera - sponges
2) Cnidarians - jellyfish
3) Platyhelminthes - flatworms
4) Nematodes - roundworms
5) Annelids - earthworms, leeches
6) Mollusks - squids, octopuses, snails
7) Arthropods - Insecta (grasshopper), Crustacea (shrimp), Arachnida (spider)
8) Echinoderms - sea stars
9) Chordata - fish, amphibians, reptiles, birds, mammals

Question 12

Porifera characteristics (6)

Answer 12

• no symmetry
• no nerve or muscle tissue
• sessile
• 2 cell layers only
• have specialized cells but no tissues or organs
• can reproduce both sexually and asexually

Question 13

Cnidarians characteristics (5)

Answer 13

• radial symmetry
• two cell layers
• gastrovascular cavity
• have stringing cells (cnidocytes) containing stingers
• body plan is either polyp (sessile, asexual reproduction) or medusa (motile, sexual reproduction)

Question 14

Platyhelminthes - flatworms (5)

Answer 14

• bilateral symmetry
• 3 cell layers
• digestive cavity with only one opening for both ingestion and egestion
• solid body with no room for true digestive or respiratory system
• body is so flat that many cells can exchange nutrients and wastes by diffusion with the environment

Question 15

Annelids - earthworms, leeches (8)

Answer 15

• segmented
• bilateral symmetry
• little sensory apparatus
• digestive track with crop, gizzard and intestine
• excretion by nephridia
• closed circulatory system
• blood with hemoglobin
• hermaphrodites

Question 16

Mollusks - squids, octopuses, snails (5)

Answer 16

• soft body
• open circulatory system
• bilateral symmetry
• radula - movable structure acting as tongue
• have gills and nephridia (for excretion)

Question 17

Arthropods (8)

Answer 17

• Insecta: grasshopper
• Crustacea: shrimp, crab
• Arachnida: spider
• segmented into head, thorax and abdomen
• more sensory apparatus => freedom of movement
• open circulatory system
• chitinous exoskeleton for protection
• waste removal through malpighian tubules