Brainscape's Knowledge GenomeTM

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


See full index

animals > lecture 3 - 02/10/24 > Flashcards

lecture 3 - 02/10/24 Flashcards

1
Q

What is phylogeny?

A

A branching diagram that shows how biological groups are related

(also an evolutionary tree)

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

Why are phylogenies important?

A

to classify organisms into groups

to understand evolutionary change and relationship patterns

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

Are phylogenies set in stone?

A

No

they are estimates

can change with new data or new analysis methods

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

How many phyla are there?

A

over 30 recognised phyla

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

What are our most distant animal relatives?

A

Poriferans
Ctenophores
Cnidarians

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

What are Phylum Porifera?

A

The sponges

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

What does sessile mean?

A

unmoving

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

What is a porifera?

A
  • sessile
  • irregularly-shaped
  • filter-feeder
  • wide variety of shapes and colours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How many species of porifera are there?

A

> 5000 descibed species

(1000s more species suspected but undescribed)

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

Describe a sponges morphology?

A

simple bag-like body plan - inner/outer cell layers and a mostly non-cellular internal matrix

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

What is the non-cellular internal matrix of a sponge called?

A

mesohyl

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

How do sponges generate a water current?

A

The choanocytes (inner layer of cells) pump their whip-like flagella

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

Are sponges symmetrical or asymmetrial?

A

asymmetrical

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

How do sponges consume food?

A

water is drawn through pores within the body wall and inflowing organic material filtered and consumed

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

What does the mesophyl contain?

A

structural elements
ameboid cells - irregular shaped microbes

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

Do sponge have organs?

A

no organs, no nervous system, no muscle tissues
very simple anatomy

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

How do sponges boost filter feeding efficiency?

A

develop channels and pockets - increase SA and boosts inflow

more choanocytes so more filter feeding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why are sponges important?

A

important in ecosystems, increases water quality

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

Why are choanocytes called ‘collar cells’

A

due to the ring of microvilli that surrounds the flagellum, and that are used for filter-feeding

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

What are choanoflagellates?

A

the mostly closely related microbial relatives of animals

have a similar appearance to choanocytes

\9some researchers view this structural similarity as evidence of homology)

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

What is homology?

A

shared ancestry

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

What nis biomineralization?

A

the biological production of hard, inorganic mineral structures

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

What do many sponges secrete?

A

hard spicules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is a spicule?

A

inorganic mineral structure

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

function of sponge spicules

A

strengthen the body wall - help deter predators

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

history of sponge spicules

A

provide some of the earliest fossil evidence of animals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What do many invertebrates have poor fossil records?

A

due to lack of mineralized body parts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Describe a sponges distribution

A

distributed globally, from nearshore to ocean floor, as well as (rarely) freshwater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What do filter feeders consume?

A

microscopic/dissolved organic matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Why are a few species of sponge carnivores?

A

adapted to live in nutrient poor deep waters where filter-feeding is ineffective

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How do carnivorous sponges catch food?

A

secrete sticky substance which sticks to very small organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is the sponge loop?

A

carbon cycling in coral reefs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

how do sponges carbon cycle?

A

convert dissolved carbon to cellular material that other species can eat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is a reef?

A

underwater mound, biological or geographical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is sequential hermaphroditism?

A

an individual can switch sex as it ages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is broadcast spawning?

A

gametes are released into external environment of the ocean

37
Q

How do sponges reproduce sexually?

A

males release gametes in their outflow (broadcast spawning) but females usually do not

internal fertilization and brooding of embryos

38
Q

how do sponges reproduce asexually?

A

freshwater species produce asexual spores (gemmules) to ensure survival under poor conditions - seasonally challenging

tiny fragments of sponges can survive and form new individuals (regeneration)

39
Q

Do sponge embryos undergo gastrulation?

A

no
early sponge embryos are usually hollow or filled, not layered, and cell-fate is more flexible

40
Q

what is indirect development?

A

where larvae and adults have distinct body plans, and maturation requires metamorphosis

41
Q

How are soft poriferans relevant to humans?

A

farmed for use as bath sponges

and used as a source of bioactive compounds (pharmaceuticals)

can be grown in active aquaculture facilities to improve water quality by filter feeding (bioremediation)

42
Q

What are soft poriferans?

A

those that lack spicules

43
Q

What is bioremediation?

A

fixing a polluted environment

44
Q

What is phylum ctenophora?

A

comb jellies

45
Q

describe a typical comb jelly

A

gelatinous, radially symmetrical, actively-swimming predator

46
Q

How do comb jellies swim?

A

using eight rows of fused cilia (combs or ctenes) and are the largest animals who use cilia for locomotion

47
Q

How many species of phylum ctenophora are there?

A

~200
(many more but too delicate to easily collect and study)

48
Q

What adaptation do ctenophores have that increases stomach SA?

A

stomach is branched

49
Q

What is between the skin and digestive lining in ctenophores?

A

between the epidermis and the gastrodermis is the mostly acellular and gelatinous mesoglea

50
Q

What are locomotory combs?

A

fused cilia rows

51
Q

how many locomotory combs do ctenophores have?

A

8 run top-to-bottom along the outside

52
Q

How are the locomotory combs controlled?

A

neurally controlled

linked to an optical sensory organ that is used for orientation

53
Q

Do ctenophores have integrated tissues?

A

yes
and simple organs

54
Q

describe ctenophore muscles

A

muscular, retractable tentacles covered in sticky, toxic cells found in most species

most have a round body

55
Q

describe ctenophore gut morphology

A

mouth at bottom, anal openings at top
(a through/complete gut)

56
Q

describe ctenophore symmetry

A

symmetrical - more organised body plan
radially symmetrical

57
Q

what is radial symmetry?

A

revealed by rotation around an axis and not a reflection across a plane

58
Q

describe ctenophore ecology

A

exclusively marine, globally distributed

prey upon microbes, marine invertebrates, fish larvae

can have large effects on food webs including fisheries (especially invasive species)

some species eat jellyfish and reuse the sting cells as weapons when hunting

some species are flattened and adapted for benthic lifestyles

59
Q

What is benthic lifestyle?

A

crawling on the sea floor

60
Q

what is a pelagic lifestyle?

A

swimming/floating

61
Q

describe ctenophore reproduction

A

most species are simultaneous hermaphrodites

sexual reproduction typically involves broadcast spawning and external fertilization (potential for self fertilization)

benthic species are atypical, internal fertilization and asexual reproduction via fragmentation and regeneration

62
Q

What happens to the embryo after cleavage in ctenophore development?

A

the embryo undergoes gastrulation

results in 2 germ layers
- outer ectoderm
- inner endoderm

63
Q

What does formation of germ layers facilitate?

A

tissue/organ development

64
Q

Do most species of ctenophores undergo direct development?

A

yes

no metamorphosis - young are ‘juveniles’ not ‘larvae’

65
Q

sponges vs comb jellies

A

biologists are conflicted on which are our most distant animal relatives

data is messy and incomplete
analysis methods are complex and debated

answer has implications for understanding the evolution of complex nervous systems

66
Q

What does sessile mean?

A

attached to the ground

67
Q

describe a typical cnidarian

A

marine
radially symmetrical
gelatinous predator that alternates between sessile and swimming phases
over 10000 species

68
Q

What are the exceptions for cnidaria?

A

many lack one of the 2 phases

many acquire nutrients from symbiotic photosynthetic microbes (zooxanthellae)

many secrete hard mineralized skeletons

many are colonial

a few freshwater and parasitic species exist

69
Q

describe a polyps

A

sessile, with mouth facing up

70
Q

describe medusae

A

mobile, with mouth facing down

71
Q

Describe cnidarian symmetry

A

radially symmetrical with notable tentacles

72
Q

describe cnidarian gut morphology

A

gut is blind (no anus) - gametes and waste expelled through mouth

73
Q

Describe cnidarian nervous system morphology?

A

a diffuse nerve network controls the body and tentacle musculature

74
Q

Describe cnidarian body morphology?

A

filled with gelatinous mesoglea - acts as a hydrostatic skeleton

75
Q

Describe cnidarian sensory system morphology?

A

tend to be more complex in medusae (some jellyfish have eyes)

use muscles to locomote

76
Q

What are cnidocytes?

A

special type of cell produced only by cnidarians

77
Q

What are nematocysts?

A

in cnidocytes

tiny but most species are covered in them (particularly tentacles)

subcellular organelles that consist of a hollow-tube coiled up in a capsule

capsule can explode outward, tangling or piercing enemies or prey and delivering potent toxins

some creatures can steal and use them (like ctenophores)

78
Q

Describe the biphasic life cycle of a cnidarian

A

(especially jellyfish) alternate between medusa and polyp phases

medusae reproduce sexually, producing larvae that swim to ocean floor and grow into polyps

polyps reproduce asexually, completing the cycle by producing numerous immature medusae

79
Q

What are the exceptions for cnidarian biphasic life cycle?

A

anemones and corals are sexually reproductive polyps

some hydrozoan jellyfishes skip the polyp stage, with larvae that mature into medusae

a few species are potentially immortal, with medusae that can revert to the immature polyp stage

80
Q

describe cnidarian coloniality

A

many species are colonial - consist of zooids

in some species the zooids are morphologically and functionally similar to one another

in some species (e.g. siphonophores) the zooids can be morphologically and functionally distinct (highly specialized zooids effectively act as the organs of a superorganism)

81
Q

What does colonial mean?

A

survive as part of a larger unit

82
Q

what is a zooid?

A

asexually produced clusters of connected, interdependent individuals

83
Q

Describe cnidarian reproduction

A

both sexual and asexual reproduction are widespread

polyps can reproduce asexually by splitting or fragmenting, then regenerating

jellyfish usually have separate sexes while corals and sea anemones tend to be hermaphroditic

synchronized broadcast spawning is common
(depends on environment cues)

the males of some box jellyfish have mating behaviours and transfer sperm directly to females

84
Q

Describe cnidarian development

A

Diploblastic

their embryos undergo gastrulation and have 2 germ layers, ectoderm and endoderm

embryo develops into a planula larvae - uses cilia to swim and find a suitable spot to settle and metamorphose

85
Q

Describe cnidarian ecology

A

Biomineralizing - sensitive to pH

reefs formed by colonial, stony corals are a critically important habitat for many species
- sensitive to ocean acidification

many species host symbiotic zooxanthellae - provide nutrients via photosynthesis
- sensitive to ocean warming
- mutually advantageous relationship

many animals prey on cnidarians
- e.g. sea turtles

86
Q

Describe cnidarian human relevance

A

tropical reefs - major ecotourism industries

jellyfish are farmed and eaten

many produce pharmaceutical bioactive compounds

cnidarian fluorescent proteins (GFPs) are a valuable tool in molecular/cell biology research

87
Q

name the key similarities among sponges, ctenophores and cnidarians

A

mostly marine, very few freshwater, no terrestrial

sexual reproduction typically involves broadcast spawning

hermaphroditism and/or sexual reproduction are widespread

all lack tissues/structures dedicated solely to respiration and excretion, relying instead on cellular-level processes

88
Q

name the important differences between ctenophores and cnidarians vs sponges

A

they have embryos with 2 germ layers due to gastrulation - sponges do not

they have complex organs formed of nervous and muscle tissues - sponges do not

they have well defined symmetrical body plans - sponges generally do not

they display greater embryological, anatomical and behavioural complexity than sponges

animals (4 decks)

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