Animalia Textbook Review

Question 1

What is the definition of an animal?

List Characteristics

Answer 1

a living organism that can move, eat, and react to the world through its senses

• eukaryotic organisms
• cells lack cell walls
• multicellular
• heterotrophs that ingest food
• motile
• form a blastula (hollow ball of cells) during embryological development

Question 2

What distinguishes an animal from animal-like protists?

Answer 2

Most animals take food into their food and digest it.

Question 3

What is the difference between invertebrates and vertebrates?

Answer 3

Vertebrate animals have a backbone and a skull while invertebrates doesn’t.

Question 4

What is the significance of the blastula during embryological development?

Answer 4

All animals begin life as a zygote that forms when a sperm fertilizes an egg. The zygote splits into two cells and so on and forms a blastula and an infolding of cells occurs at a particular spot in the ball. The infolding eventually pushes all the way though the hollow ball, forming a digestive tract that connects both ends.

two types of blastopore.
1. protostome - when the open ending is mouth (mouth develops from blastopore)
2. deuterostome - when the open ending is the anus (anus develops from blastopore)

Question 5

Describe the types of symmetry evident in the animal kingdom and give an example animal for each.

Answer 5

There are three types of symmetry: asymmetry, radial, and bilateral

1. asymmetry
   no symmetry.

Examples: sponges

2. Radial
   - shaped like a cylinder or bowl
   - lack head and have no real front or back

Examples: cnidarians - jellyfish, coral
echinoderms - sea urchins, sea stars

3. Bilateral
   have a distinct head (anterior end), tail (posterior end), back (dorsal) surface, bottom (ventral) surface, and two side (lateral) surface

Examples: butterfly, shark, lobsters, flatworms

Question 6

What characteristics are unique to vertebrate animals?

Answer 6

• skull
• backbone
  These skeletal features protect the main parts of the animal’s nervous system.

skeletal parts : shoulders and pelvis that support paired limbs

Question 7

What advantage does cephalization give bilaterally symmetrical animals?

Answer 7

cephalization - development of a distinct head with sense organs

Therefore, it allows the animals to detect prey and predators in the direction that the animals are moving.

Question 8

The flatworm’s body plan is well-suited to the animal’s lifestyle. Justify this statement.

Answer 8

A flatworm is bilaterally symmetrical allowing them to move in a particular direction in the environment and move quickly. Their eyes are located on their head which detects prey and predators in the direction they are moving.

Question 9

Explain the evolutionary significance of the amniotic egg.

Answer 9

An amniotic egg is an waterproof egg with a shell that allowed vertebrates to reproduce on land.

Question 10

Compare and contrast the evolutionary steps that allowed plants and animals to transition from water to land.

Answer 10

Evolutionary steps for plants:
1. plants without leaves, stems, seeds colonize areas where water and land meet.
2. plants develop lignin and begin to stand up right - lignin is chemicals that hardens cell wall, they also develop vascular tissue, to transport water and nutrients.
3. development of seeds - embryos covered in protective covering
4. flowering plants - reproductive structure that attracts animals to help spread seeds

Evolutionary steps for animals:
1. hinged jaws (for catching and eating prey) and paired limbs (for catching prey and moving around)
2. development of lungs and lung derivatives like air sacs (give fish buoyancy)
3. having two sets of paired limbs that can support the animal which made it possible for vertebrates to inhabit the land

Question 11

Describe how tetrapods may have evolved from fish-like ancestors.

Question 12

Which phylum has the simplest animal?

Answer 12

Porifera

They do not have a nervous, digestive or circulatory system. The organisms rely solely on water flow to obtain nutrients and remove waste

Question 13

What two general categories are often used to classify animals?

Answer 13

Vertebrates and Invertebrates

Question 14

What are three evolutionary steps in vertebrates? Why is each significant?

Answer 14

1. Hinged jaws - enabled vertebrates to capture and eat a wide variety of prey
2. development of paired limbs - enabled vertebrates to catch prey and move around
3. lungs and lung derivatives (air sacs) - give fish buoyancy
4. sets of paired limbs - support animal and made it possible for vertebrates to inhabit on land