Brainscape's Knowledge GenomeTM

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


See full index

Biodiversity > Lecture 10: Introduction to animal evolution > Flashcards

Lecture 10: Introduction to animal evolution Flashcards

1
Q

Elements of biodiversity:

3 types and similarities

A
  • Ecological Diversity
  • Genetic Diversity
  • Organismal Diversity
    • all only linked by populations –
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Features of animalia:

A
  • eukaryote
  • multicellular, held together by collagen
  • heterotrophic, feed by ingestion (usually)
  • muscle & nervous tissue unique to animals
  • lack cell walls
  • unique cell junctions:
    • tight junctions
    • desmosomes
    • gap junctions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

3 types of junction:

A
  • tight junctions (between plasma membrane of adjacent cells, between space)
  • desmosome (anchoring junction)
  • gap junctions (communicating junction)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

life-history features of animals

A
  • most reproduce sexually
  • life cycle dominated by the diploid stage
  • small flagellate sperm fertilises a non-motile egg (heterogamete)
  • blastula in early development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

early embryonic development:

A

zygote –cleavage–> eight cell stage –cleavage–> blastula –Gastrulation–>Gastrula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Blastula:

A

hollow ball of cells.

inside = blastocoel

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

Gastrulation:

A

pinching inwards on itself

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

Gastrula:

A
  • Endoderm inside
  • Blastocoel middle layer
  • ectoderm outside
  • blastopore-‘entrance’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Hox genes:

A

special genes that regulate development in animals

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

Number of hox genes is correlated with

A

the complexity of the animal body plan

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

Variation in when and where Hox genes are expressed in the developing embryo is the basis

A

of the diversity of animal body plans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Origin of animals thoughts? brief

A

colonial heterotrophic flagellate similar to a choanoflagellate protozoan.

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

Reasons why to origin of animals

A
  • single flagella surrounded by a collar of microvillae used for filter feeding
  • single flagella consistent with the monociliate condition believed to be primitive in animals
  • flagella base structure closely resembles cilia base in animals
  • similar mitochondrial structure
  • DNA evidence
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

ontogeny reflects

A

phylogeny

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

how have evolutionary relationships among animals been concluded?

A 
-Paleontological evidence
appearance in the fossil record
-Anatomical similarity
shared, derived homologous structures
-Developmental similarity
patterns of cell division and embryonic stages
-Biochemical similarity
DNA, RNA and protein similarity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Traditional view of animal evolution is based on..

A

BODY PLANS

  • True tissues formed following gastrulation
  • Symmetry
  • Presence of a body cavity or coelom
  • Pattern of coelom development
17
Q

Gastrulation results in

A

..at least two tissue layers (endoderm and ectoderm)

  • Separates Parazoa (inc. sponges) from Eumetazoa
  • True tissues enable specialisation and organ development
18
Q

Radial and bilateral symmetry:

A

Separates Radiata (jellyfishes) from Bilateria

  • Radiata have a top/bottom or oral/aboral side, bilateria have anterior/posterior and dorsal/ventral sides
  • Radiata are diploblastic, Bilateria triploblastic
  • Bilateral symmetry associated with cephalisation and active lifestyle
19
Q

Evolution of body cavities:

A

Acoelomate
pseudocoelomate
coelomate

20
Q

coelomate

A

(e.g. earthworms Annelida)

coelom lined with mesoderm

21
Q

Acoelomate

A

(e.g. flatworms Platyhelmithes)
solid body between digestive tract and outer body wall
lack digestive tract or incomplete without anus

22
Q

pseudocoelomate

A

(e.g. roundworms Nematoda)

coelom not completely lined with mesoderm

23
Q

Functions of the body cavity:

A

protection
allows organ growth
allows movement (hydrostatic skeleton)

24
Q

Coelom development in protostomes:

A

(Mollusks, annelids, arthropods)

  • eight cell stage: spiral & determinate
  • Schizocoelous: solid masses of mesoderm split to form coelom
  • mouth develops from blastopore
25
Q

Coelom development in Deuterostomes:

A

(echinoderms, chordates)

  • radial and indeterminate
  • Enterocoelous: folds of archenteron form coelom
  • Anus develops from blastopore
26
Q

NEW PHYLOGENY BASED ON MOLECULAR GENETICS:

A

compared to traditional:

  • Parazoa and Radiata branches supported
  • Monophyly of Deuterostomes supported
  • Two Protostome clades
  • -Lophotrochozoa – annelids and molluscs - named for a crown of cilia on the larva (“lophophore”)
  • -Ecdysozoa – arthropods and nematodes - named for shedding of exoskeleton (“ecdysis”)

-Platyhelminthes – thought to have had, then lost coelom

Biodiversity (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions