Midterm Flashcards
(98 cards)
1
Q
Early group of large, soft-bodied, multicellular macroscopic eukaryotes dating back 560 mya
A
Ediacaran biota
Early members include alga
2
Q
Examples of early-diverging groups of animals
A
Sponges and cnidarians
3
Q
Sponges
A
Filter feeders. Water drawn through pores and out through top opening
Lack true tissues
4
Q
Choanocytes
A
Flagellated collar cells, generate current though the sponge and ingest suspended food
5
Q
Cnidarians
A
Have true tissues
Oldest group of animals (680 mya)
Sessile and Motile forms (Jellies_
6
Q
Diversity of large animals increased during ______. Earliest fossil appearance
A
The Cambrian explosion (535-525 y.o)
7
Q
Cambrian explosion & possible explainations
A
Most fossils are bilaterians
- New predator-prey relationships
- A rise in atmospheric oxygen
- The evolution of the Hox gene complex
8
Q
Bilaterians
A
Complete digestive tract & bilaterally symmetric form
9
Q
Categorize animals according to ______.
A
Body Plan
10
Q
Three Important aspects of animal body plans
A
- Symmetry
- Tissues
- Body cavities
11
Q
Radial symmetry
A
No front and back or left and right (Mirror images)
Ex. Sea Anemone
12
Q
Bilateral symmetry
A
Two-sided symmetry
Many also have sensory equipment concentrated in anterior end
Ex. Lobster
13
Q
Tissues
A
Collections of cells isolated from other tissues by membranous layers
14
Q
Three Germ Layers
A
Give rise to tissues & organs of animal embryo
Ectoderm: Cover embryo surface
Endoderm: Innermost layer lines digestive tube
(Animals with radial symmetry only have these two)
Mesoderm: Fills space between ectoderm & endoderm in all bilaterally symmetric animals
15
Q
Body Cavities
A
A fluid or air-filled space between the digestive tract and the outer body wall
-Most bilaterians
- Can cushion suspended organs
- Hydostatic Skeleton- noncompressible fluid that acts like a skeleton
- Enable internal organs to grow and move independently of the outer body wall
16
Q
How to determine relationships among animal phyla
A
Combine molecular data from multiple sources with morphological data to determine the relations
17
Q
Bilaterians are divided into three main groups
A
- Deuterostomes
Ex. Acorn Worm, Sea Star,Urchins (Chordates)
Majority of inverebrate species:
- Lophotrochozoans
Ex. Mollusca (Octopus), (Ammelida) Fireworm
- Ecdysozoans
Ex. Nematoda (Roundworm), (Arthropoda) Spiders
18
Q
Majority of known animal species are
A
Bilaterian
19
Q
Vertebrates (Chordata)
A
Most successful groups of animals
- Vertebrae- Bones makes up backbone
- Well-defined head w. a brain, eyes, & sensory organs
- Cranium (skull)
Fossils formed during Cambrian explosion
20
Q
Characters of chordates
A
- Notochord [Flexible rod provides skeletal support]
- Dorsal, hollow nerve cord [Develops into brain & spinal cord]
- Pharyngeal slits/cleft [Filter suspension, gills, parts of the head]
- Muscular, post anal tail
21
Q
Early Vertebrates (Conodonts)
A
Soft, bodied jawless animals with hooks in their mouth
Today’s jawless vertebrates
- Hagfishes & Lampreys
22
Q
Gnathostomes
A
Jawed Vertebrates - Adapted for predation (fins, tails, jaws)
- Chondrichthyans
- Ray-finned fishes
- Lobe-fins (Humans, Animals w. Legs!)
23
Q
Chondrichtyes
A
Cartilaginous fish composed of cartilage
Ex. Sharks, rays
Largest & most successful predators
24
Q
Lobe-Fins (osteichthyans)
A
Bony fish
Rod-shaped bones surrounded by a thick layer of muscle in their pectoral and pelvic fins
- Adapted to life on land and gave rise to
- Tetrapod
- Vertebrates with limbs and digits
- Coelacanths
- Lungfishes (both gills and lungs & can gulp air into lungs)
-Tetrapods
25
Characteristics of Anthropods
Jointed Appendages
Segmented body
Exoskeleton
26
Insects
Include more species than all other forms of life combined
Live in every terrestrial habitat and in fresh water
Leopidopterans (Moths & Butterflies) Metamorphisis
Flight is key
27
Insect & plant diversity declined during:
Cretaceous mass extinction (65mya)
28
Significant even in vertebrate history
Fins of lobe-fins evolved into the limbs and feet of tetrapods
Fins became progressively more limb-like over time leading to tetrapods (365 mya)
29
Tiktaalik (fishapod)
Both fish and tetrapod traits
30
Amphibians
Salamanders, frogs, and caecillians
Some entirely aquatic others restricted to moist areas
31
Amniotes
Group of tetrapods; Reptiles, birds, and mammals
Named for their amniotic egg
- Contains extraembryonic membranes that nourish and protect the embryo
Most have a shell
-Prevents dehydration in air
** Egg was adaptation that helped amniotes occupy wider range of terrestrial habitats than amphibians
32
Reptiles
Have scales that create waterproof barrier
Lay shelled eggs on land
33
Ectothermic
Absorb external heat as main source of body heat
34
Endothermic
Capable of keeping the body warm through metabolism
35
Mammals
Lineage of amniotes
**Evolved from synapsids (180mya)
- mammary glands that produce milk
- hair
- flat layer under skin
- high metabolic rate (endothermy)
- Differentiated teeth
36
Three living lineages of mammals
Monotremes
(Egg-laying mammals)
Marsupials
(External pouch)
Eutherians
(Embryonic development is completed in a uterus inside mothers body)
37
Homosapiens
Originated in Africa about 200,000 y.a
Evolution of bipedalism
38
Species that has suffered greatest human-caused extinction
Molluscs (pearl mussels)
39
Angiosperms
Primary producers important to agriculture
Monocots (One cotyledon) & Eudicots (Two cotyledon)
40
Difference between Monocots & Eudicots
Embryos: 1 vs. 2 cotyledons
Leaf Venation:
- Mono veins parallel
- Eudi veins netlike/branching
Roots:
- Mono roots are fibrous
- Eudi roots have a taproot (main root)
41
Three basic organs of plants
Roots
[Rely on sugar produced by photosynthesis in shoot system]
Stems
Leaves
42
Shoot system
Includes leaves, stems, and flowers (angiosperms)
43
Shoots
Rely on water and minerals absorbed by the root system
44
Roots
Anchor the plant
Absorb minerals & water
Store carbohydrates
Root hairs - Absorb water & minerals ; increase surface area
45
Taproot system
Exist in tall, erect plants with large shoot masses
- Taproot (main vertical root)
- Lateral roots (branching of taproot)
46
Leaves
Main photosynthetic organ
Gas exchange, dissipation of heat, defense (cacti spines)
47
What tissues does each plant organ have?
Dermal
[Protective cover]
Vascular
[Transports materials between root and shoot system]
Ground
[Metabolic functions and provides support]
48
Major types of plant cells
```
Parenchyma
Collenchyma
Sclerenchyma
Xylem (Water-conducting cells)
Phloem (Sugar- conducting cells)
```
49
Parenchyma
- Thin, flexible primary walls
- NO secondary walls
* *Performs most metabolic functions like photosynthesis
* * Cells are living when mature and retain the ability to divide and differentiate
50
Collenchyma
- Support young parts of the plant shoot
- Thicker, uneven primary cell walls
- Flexible support without restraining growth
51
Sclerenchyma
Rigid due to thick secondary walls with lignin
- support mature, nongrowing plant parts (wood)
- dead at functional maturity
52
Two type of sclerenchyma cells
Sclerids- impart hardness to nutshells and seed coats
Fibers- hemp fibers used to make rope
53
Water-conducting cells of xylem
Dead at functional maturity
Tracheids (move water through pits)
Vessel elements
54
Sugar-conducting cells of phloem
Alive at functional maturity
Sugar transported through sleve cells in seedless vascular plants
Angiosperms sugars are transported in sleve-tube elements
55
Sleve plates/tubes
Allow fluid to flow between cells
Sleve tube elements lack organelles. Have companion cell whose nucleus and ribosomes help
56
Indeterminate growth
Plant grows throughout life
Possible with meristems (embryonic tissues)
Meristems give rise to initials (stem cells) & derivates (mature tissues)
57
Determinate growth
Plant organs cease to grow at a certain size
58
Apical Meristems
elongate shoots & roots
**Primary Growth**
Protected by the root cap
59
Lateral Meristems
Thickness to woody plants
| **Secondary Growth**
60
Two Lateral Meristems
Vascular Cambium
[Secondary xylem (produces wood) & secondary phloem (produces bark)]
Cork Cambium
Produces cork cells & replaces with periderm
Cork cells contain waterproof suberin which acts as protective barrier
61
Axillary buds
Dormant due to apical dominance
When released from dormancy, buds give rise to lateral shoots (branches)
62
Stomata
Allow CO2 & 02 exchange b/w air and photosynthetic cells in leaf
63
Guard cells
Regulate opening and closing
64
Ground tissue (Mesophyll)
Parenchyma cells specialized for photosynthesis & gas exchange
65
Veins
Fluid transport and provide structure to the lead
Enclosed by a protective bundle sheath
66
Secondary growth
Increases diameter of stems and roots in woody plants
Gymnosperms & Eudicots
67
Dendrochronology
Analysis of tree ring growth patterns to study past climate change
68
Physiology
Study of biological functions organism performs
69
Cells are organized into
Tissues
[Groups of cells]
Organs
[Different types of tissues]
Organ systems
[Groups of organs]
70
Tissues
Epithelial
[Outside of body & lines organs]
Connective
[Holds skins and other organs in place]
Muscle
[Skeletal, smooth, cardiac]
Nervous
71
Regulator animals
Use internal mechanisms to control internal change
72
Conformer animals
Allows internal condition to change with external changes
73
Thermoregulation
Animals maintain internal temperature within tolerable range
Controlled by hypothalamus in mammals
74
Endothermic
Generate heat by metabolism
Maintain stable body heat (mammals)
75
Ectothermic
Gain heat from external sources
Regulate temperature by behavioral means
Consume less food because heat source is largely envior.
76
Radiation
Emission of waves (Sun bathing)
77
Evaporation
Removal of heat from surface of a liquid (Cooling)
78
Convection
Transfer of heat by movement of air or liquid past suface (breeze)
79
Conduction
Direct transfer of heat between objects in contact with another (sitting on a hot rock)
80
Vasodilation
Promotes heat loss (widening of blood vessels)
81
Vasoconstriction
Reduces heat loss (constricting of blood vessels)
82
Countercurrent exchange
Transfer heat between fluid flowing in opposite directions & reduce heat loss
(Birds & Mammals)
83
Homeostasis
Maintain "steady state"
Thermoregulation
Fever- result of change to set point for a biological thermostat
84
Endocrine system
Hormones released into the bloodstream
Gradual changes that affect the entire body
85
Receptors
Only Cells with receptors for a certain hormone can respond to it
86
Nervous System
Neurons trasmit signals (nerve impulses) along axons
Immediate and rapid response to the environment
87
Simple Endocrine Pathway
Endocrine cells respond directly to stimulus by secreting hormone directly into bloodstream to target cells
** does not rely on sensor from nervous system
88
Neuroendocrine Pathways
Hormone pathways respond to stimuli from the envior. rely on a sensor
Signals travel to the pituitary gland where hormones are released from posterior pituitary
89
Posterior pituitary
Secretes oxytocin (milk production) & antidiuretic hormone (ADH) (helps to conserve water)
90
Osmoregulation
Animals control solute concentrations in the interstitial fluid and balance water gain & loss
(Dehydration)
91
Functions of excretory system
Filtration
Reabsorption
Secretion
Excretion (urine)
92
Kidneys
Conserve water, excretory organs of vertebrates
-Excretion & osmoregulation
Filter blood, remove nitrogenous wastes, excess water, and sales
93
Essential amino acids
Must be obtained from food
94
Main stages of food processing
Ingestion
Digestion
Absorption
Elimination
95
Substrate Feeders
Live in or on their food source
96
Fluid feeders
Such fluid from living host
97
Intracellular digestion
Food particles are engulfed by phagocytosis
98
Extracellular digestion
Breakdown of food particles outside of cells
