Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Bio 94: Exam 3 > Chapter 32: An Overview of Animal Diversity > Flashcards

Chapter 32: An Overview of Animal Diversity Flashcards

1
Q

What are some basic characteristics of all animals?

A
  • Multicellular
  • Heterotrophic eukaryotes
    • tissues develop from embryonic layers
  • Lack cell walls
  • Lack chloroplasts (have mitochondria)
  • Bodies held together by collagen
  • Have nervous/muscle tissue
  • Chemoheterotrophs
  • Capacity for locomotion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Explain how a sperm fertilizes an egg.

A
  1. The sperm touches the jelly coat of the egg and is triggered to release enzymes to break it down.
  2. Acrosomal reaction
    • receptors on the egg surface bind to molecules on the sperm surface
  3. Polyspermy is blocked.
  4. Cortical reaction causes tail of sperm to fall off and sperm head fully enters the egg.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is acrosomal reaction?

A

Acrosome at tip of sperm releases enzymes to break down the jelly coat and egg receptors bind to sperm receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is polyspermy?

A

When multiple sperm fertilize an egg (this gets prevented)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the steps of embryonic development?

A
  1. Zygote undergoes mitosis (cleavage)
  2. 8-cell embryo stage
  3. Cleavage gives you a blastula
    • blastocoel forms
  4. Gastrulation
    • one end of blastula folds inwards
    • 3 germ layers emerge
  5. Gastrula is formed and now embryo develops
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is cleavage?

A

When a cell divides by mitosis, but there is no cell growth between each division.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a blastula?

A

A ball of cells containing a blastocoel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is a blastocoel?

A

Fluid cavity inside of the blastula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a gastrula?

A

Embryonic stage where the embryo has 3 germ layers:

  • Ectoderm
  • Mesoderm
  • Endoderm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

During embryonic development, what does the blastocoel develop into?

A

Mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is gastrulation?

A
  • Forming of the gastrula with different layers of embryonic tissue
  • Movement of cells from the blastula surface to the interior of the embryo (blastula folds inwards)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a larva?

A

Early, immature form of an animal that is morphologically different from the adult.

E.g., tadpole to frog

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is morphogenesis?

A

Process where cells occupy their appropriate location

- includes gastrulation and organogenesis (formation or organs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is metamorphosis?

A

When the larva transforms the juvenile animal into an adult, but is not yet sexually mature.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the ancestor of animals?

A

Protist; choanoflagellates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The common ancestor of living animals may have lived between:

a. 700 and 770 billion years ago
b. 700 and 770 million years ago
c. 500 and 550 billion years ago
D. 500 and 550 million years ago

A

b. 700 and 770 million years ago

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why are choanoflagellates considered the closest ancestor to animals?

A
  1. Choanoflagellates are identical to choanocytes (collar cells) found in sponges and other animals
  2. These choanocytes, however, are not found in other protists, fungi or plants.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Animals have cadherin proteins and choanoflagellates have cadherin-like proteins. What is the difference between them?

A

The cadherin proteins in animals have the “CCD” domain, which choanoflagellate cadherin-like proteins lack.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do cadherin proteins do?

A

Hold the animal and choanoflagellate cells together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are Ediacaran biota?

A

Fossilized multicellular eukaryotes dating back to 560 million years ago

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When did the Cambrian period begin?

a. 735 to 725 billion years ago
b. 735 to 725 million years ago
c. 535 to 525 billion years ago
d. 535 to 525 million years ago

A

d. 535 to 525 million years ago

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the Cambrian explosion?

A

Rapid diversification of multicellular animals

  • hunters arose
  • bilaterians arose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are bilaterians?

A

Animals with:

  • bilaterally symmetric form
  • complete digestive tract
  • one-way digestive system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q
  1. What did the Ordovician period give rise to?
  2. When did this occur?
    a. 650 million years ago
    b. 650 billion years ago
    c. 450 million years ago
    d. 450 billion years ago
A
  1. Land animals

2. c. 450 million years ago

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

When did vertebrates transition to land?

a. 365 billion years ago
b. 365 million years ago
c. 425 billion years ago
d. 425 million years ago

A

b. 365 million years ago

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What lived in the Mesozoic era?

A
  • dinosaurs
  • mammals
  • flowering plants and insects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What lived in the Cenozoic era?

A
  • terrestrial and marine animals
    • dinosaurs went extinct
    • global climate cooled
28
Q

Is the Kingdom Animalia monophyletic, paraphyletic, or polyphyletic?

A

Monophyletic

29
Q

What 6 characteristics differentiate amongst the animal phyla?

A
  1. Body plan
  2. Organs
  3. Reproduction
  4. Support
  5. Life cycles
  6. Methods of feeding
30
Q

What is radial symmetry?

A

Parts radiate from the center. Any slice through the central axis will give you a mirror image.

E.g., a sea anemone

31
Q

What is bilateral symmetry?

A

One slice gives you only one mirror image; a left and a right side.

E.g., a lobster

32
Q

True or false:

Radial animals often move actively and have a central nervous system, whereas bilateral animals are often sessile or planktonic, meaning they either drift or swim weakly.

A

False

Bilateral animals often move actively and have a central nervous system, whereas radial animals are often sessile or planktonic, meaning they either drift or swim weakly.

33
Q

What other morphological characteristics do bilateral animals have?

A
  1. Dorsal (top side)
  2. Ventral (bottom side)
  3. Anterior (head)
  4. Posterior (tail)
  5. Cephalization (development of head)
34
Q

Do sponges have symmetry?

35
Q

What are the 3 germ layers of tissues?

A

Ectoderm
Mesoderm
Endoderm

36
Q

What does the ectoderm develop into?

A

(Outer layer of embryo)

Develops into nervous system and skin.

37
Q

What does the mesoderm develop into?

A

(Middle layer of embryo)

Develops into heart, kidneys and muscles.

38
Q

What does the endoderm develop into?

A

(Inner layer of embryo)

Develops into the archenteron (digestive tube).

39
Q

What is a diploblastic animal?

A

Animals that have an ectoderm and endoderm, but lack mesoderm.

E.g., cnidarians

40
Q

What is a triploblastic animal?

A

Animals that have all 3 germ layers: ectoderm, mesoderm, and endoderm.

41
Q

All bilaterally symmetrical animals are ___________ (diploblastic/triploblastic)?

A

triploblastic

42
Q

Which germ layer lines the pouch that forms during gastrulation?

43
Q

What is a body cavity?

A

A fluid or air filled space between the digestive tract (from endoderm) and the outer body wall (ectoderm).

44
Q

What is a coelom?

A

Body cavity, derived from the mesoderm.

45
Q

There are 3 types of coelomates, what are they?

A
  1. Coelomates
  2. Pseudocoelomates
  3. Acoelomates
46
Q

What is a coelomate?

A

A triploblastic animal with a true coelom (body cavity)

  • this means the coelom is formed entirely from the mesoderm and is surrounded only by the mesoderm

E.g., earthworms

47
Q

What is a pseudocoelomate?

A

A triploblastic animal who’s coelom (body cavity) is formed from the endoderm and mesoderm

  • this means the coelom is surrounded by the endoderm and mesoderm

E.g., roundworms

48
Q

What is an acoelomate?

A

A triploblastic animal that completely lacks a coelom (body cavity)

  • this means that the endoderm and the mesoderm are touching
49
Q

What are the advantages of having a coelom?

A
  • creates a medium for circulation
  • makes space for internal organs
  • a hydrostatic skeleton
    • fluid filled chamber
    • allows movement
50
Q

A pseudocoelom is derived from the ____________.

A

Blastocoel

51
Q

There are two types of cleavage. What are they?

A
  1. Spiral and determinate

2. Radial and indeterminate

52
Q

Which type of cleavage symmetry do protostomes have?

A

Spiral and determinate

53
Q

Which type of cleavage symmetry do deuterostomes have?

A

Radial and indeterminate

54
Q

What is spiral and determinate symmetry?

A

Spiral
- planes of cell division are diagonal to vertical axis of embryo

Determinate
- all cells have determined fate from early on

55
Q

What is radial and indeterminate symmetry?

A

Radial

- planes of cell division are parallel or perpendicular to the vertical axis of the embryo

56
Q

What are protostomes?

A

Organisms with

  • Spiral, determinate cleavage
  • Mesoderm splits into two balls to form the coelom
  • Blastopore develops into the mouth
57
Q

What are deuterostomes?

A

Organisms with

  • Radial, indeterminate cleavage
  • Folds in the mesoderm and archentron form coelom
  • Blastopore develops into the anus
58
Q

What are the five key points about the animal phylogenetic tree?

A
  1. All animals share a common ancestor
  2. Sponges are basal animals
  3. Eumetazoa is a clade of animals with true tissues
  4. Mostly belong to clade Bilateria
  5. Three Clades of Bilateria
    • all are invertebrates except for chordata
59
Q

What are the 3 clades of Bilateria?

A
  1. Deuterostomia
  2. Lophotrochozoa
  3. Ecdysozoa
60
Q

What does the clade Deuterostomia include?

A
  • Hemichordates
  • Echinoderms
  • Chordates

Hemichordates and chordates have gill slits, echinoderms do not.

61
Q

True or false:

The phylum Chordata is not the only phylum that contains vertebrates.

A

False

The phylum Chordata is the ONLY phylum that contains vertebrates.

62
Q

What does the phylum Ecdysozoa include?

A
  • Nematodes, arthropods
  • Have external skeletons

They do ecdysis

63
Q

What is ecdysis?

A

Process of shedding old exoskeleton

64
Q

What are the characteristics of Lophotrochozoans?

A
  • Have a lophophore
    • tentacle feeding structure
  • Go through a larval stage called Trochophore Larva
65
Q

Which of the following questions is not a focus of ongoing research today?

a. Are sponges monophyletic?
b. Are acoelomate flatworms basal bilaterians?
c. Are animals monophyletic?
d. Are ctenophores basal metazoans?

A

c. Are animals monophyletic?

Bio 94: Exam 3 (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions