Exam 2 Flashcards
(180 cards)
1
Q
Protists
A
Eukaryotes that are not fungi, plants or animals
2
Q
Four major clades of eukaryotes
A
Excavata
“SAR”
Archaeplastida
Unikonta
3
Q
Photoautotroph
A
Protists that carry out photosynthesis. A producer
4
Q
Chemoheterotroph
A
A protist that derives its energy from chemicals and needs to consume other organisms in order to live. A consumer
5
Q
One example of a photoautotroph
A
Algae
6
Q
One example of a chemoheterotroph
A
Protozoan
7
Q
Archaeplastida subclade
A
Red and green algae
8
Q
Stramenopiles clade
A
Brown algae and diatoms
9
Q
Prokaryote meaning
A
Pro = before
Kary = nucleus
10
Q
Two domains of prokaryotic cells
A
Bacteria
Archaea
11
Q
How many years of evolution does the tree of life show?
A
3.6 billion years of evolution
12
Q
2 social types of prokaryotic cells
A
Unicellular
Colonial
13
Q
Unicellular
A
Organism consisting of a single cell
14
Q
Colonial
A
Groups of physically connected individuals with each individual carrying out all the necessary functions for life. They divide without fully separating.
They are not multicellular
15
Q
Coccus/cocci
A
Round
16
Q
Basillus/bacilli
A
Rod-shaped
17
Q
Strepto
A
Chain
18
Q
Diplo
A
Pair
19
Q
Spirochete/spirillum/spirilli
A
Spiral
20
Q
Staphylo
A
Bunch/cluster
21
Q
Plasma membrane in prokaryotes
A
Separation between the cell from the surrounding environment where the cell interior environment is very different from exterior environments.
Cells expend a lot of energy to maintain this chemical balance
22
Q
Purpose of a cell wall
A
Structural supports
Additional filtering
Preventing over expansion
23
Q
Cell wall types in bacteria
A
Gram +
Gram -
24
Q
Gram-positive bacteria characteristics
A
One lipid layer (Membrane)
Thick peptidoglycan (wall)
Affects antibiotic function
25
Gram-negative bacteria characteristics
Two lipid layers (membranes)
Thin peptidoglycan (wall)
Affects antibiotic function
26
Gram stain procedure
Identifies bacterial cell wall type
27
Capsule or slime layer
Outside of the cell wall
Adheres to surface
Prevents dehydration
Protects from sterilization
The cause of biofilms
28
Endospore
The protected resting stage of bacteria where they copy chromosomes and have many protective layers. They remove water, shut down metabolism and outer cell lyses.
29
Bacteria in endospor can survive what?
Without nutrients
UV radiation
Desiccation
Extreme heat
Freezing
Chemical disinfectant
30
Taxis
Movements or orientation toward or away from a stimulus
31
Prokaryotes typically exhibit this form of taxis
Chemotaxis
32
Flagella
A hairlike appendage that protrudes from certain cells that enables movement and chemotaxis
33
Flagella evolution
Flagella evolved through analogous means
34
Prokaryote internal structure regarding dna
DNA in nucleoid region
Chromosome one single circular strand which contains the genes for growth metabolism and cell structure
DNA is also found in plasmids
35
Plasmids
Tiny rings of DNA with 5 to 100 genes not required for survival
Taking up from fragments of DNA from other species
Plasmids have their own jeans for replication
36
Potential plasmid qualities
Antibiotic resistance
Poison resistance
Toxin production
Digestion of particular substance
Virulence
37
Binary fission
Asexual reproduction by a cell splitting in two
38
Genetic recombination
Alleles being brought together in new combinations
39
Genetic recombination
Happens in eukaryotes as part of sexual reproduction
Some pieces of chromosomes swapped when gametes (eggs, sperm) are made
Result in different combination of alleles in offspring than in parents
40
Fertilization
Gamete fusion within same species
Both result in different combination of alleles in offspring than in parents
41
Horizontal gene transfer
Alleles transferred between existing individuals (Genetic recombination - prokaryotes resulting in different combination of alleles in an existing individual)
42
Obligate aerobes
Metabolic diversity- type of respiration
O2
43
Facultative anaerobes
Can switch between aerobic and anaerobic respiration
Don’t require O2, not killed by O2
44
Obligate anaerobes
Killed by atmospheric concentrations of O2 (~20%)
Methanogens
45
Methanogens
Strict anaerobes
Important anaerobic decomposers
Facilitate digestion
Produce methane as a by-product
46
Ecological role
The major ways in which the species interacts with other species and affects its ecosystem
Many ecological roles are closely related to the metabolism type of the organism
There are also other ecological roles like methanogen and Nitrogen-fixer
47
Cyanobacteria today
Producers
Some are also important Nitrogen-fixers - convert atmospheric N2 into a form of Nitrogen (like nitrates) that is usable by plants
48
The majority of bacteria are what ecological role?
Decomposers
They are absolutely essential for nutrient cycling
49
Extremophiles and examples
Adaptations for living under extreme environmental conditions
Archeans – up to 20% of global biomass
Methanogens
Important part of plankton communities
50
Halophiles
Extreme salinity
51
Bacterial Nitrogen fixers and what they do
Convert atmospheric N2 gas into a form of N that is usable by plants (like nitrates or nitrites)
Cyanobacteria
Root nodule Rhizobia
52
What do we need Nitrogen for?
Major component of proteins and nucleic acids
Amino acids!
53
Root nodules containing Rhizobia
Bacteria as N-fixers
54
Protists
Eukaryotes that aren’t fungi, plants, or animals
55
What is an algae?
Any photosynthetic protist
Metabolic mode = Photoautotroph
Ecological role = Producer
56
What determines which wavelengths of light an algae can absorb?
Photosynthetic pigments that have a specific wavelength they can absorb and the light they can't is reflected in their color
Chloroplasts
57
Primary endosymbiosis of cyanobacteria resulted in what?
First photosynthetic eukaryotes
58
What is the evolutionary origin of chloroplasts?
A primitive cyanobacteria that was engulfed by non-photosynthetic cells
59
What clade are the red and green algae in?
Archaeplastida
60
What are green algea
Protists that come in different cellular organizations
61
What are red algae
Most multi-cellular protists
62
Where are red algae found? What are commercial uses of red algae? What is their ecological importance?
Found in warm marine waters
Source of agar – growth medium
Carrageenan – natural food additive for thickening
Nori
Lay down calcium carbonate
Reef-builders
Food for marine life
63
Where are green algae found? What is their ecological importance?
Fresh water
Important habitat and primary producers in aquatic food webs
64
Secondary Endosymbiosis of cyanobacteria
Something engulfed a red or green algae and the engulfed algae evolved into new plastids, like chlorophasts
65
What subclade are diatoms and brown algae in?
Stramenopiles which are photosynthetic
Secondary endosymbiosis of red alga
66
What kind of wall/shell do diatoms have?
Glass-like wall for protection with pores to exchange materials with environment
67
Diatoms
Unicellular – pennate or centric protists with glass-like walls
68
What is the ecological importance of diatoms?
1/5 of O2 production
Important in aquatic food webs
69
What is the role of diatoms in the global carbon cycle?
Carbon fixers
70
Where are brown algae found? What are important ecological roles of brown algae?
Cold, marine waters
Important marine habitat
71
What is the origin of the plastids in brown algae and diatoms?
Evolved from engulfed red algae
72
What is a protozoan?
Chemoheterotrophic protist
Metabolic mode = Chemoheterotroph
Ecological role = Consumer
(some predators, some pathogens)
73
What is a mixotroph?
They are both photoautotroph and chemoheterotroph
74
How do Plasmodium and Trypanosoma hide from host immune systems?
They change surface proteins so as not to be identified
75
What is the vectors for Plasmodium and what disease does it cause?
Vectored by Anopholes mosquitoes
Malaria
76
What are the vectors for Trypanosoma and what diseases does it cause?
Human parasites
African sleeping sickness (tse tse fly)
Chagas’ disease (kissing bug)
77
Why are Plasmodium life cycles considered complex?
Two hosts (mammal/bird and mosquito)
Sexual and asexual reproduction
78
How is Giardia transmitted?
From untreated sewage in developing countries or contamination of natural waters
79
Gardia
Intestinal parasite
Cattle and deer have this
Cramps, diarrhea
80
Dinoflagettes and their evolution
A protists with two flagella
Secondary endosymbiosis of red algae
Many are mixotrophic
81
Describe an example of a dinoflagellate that is ecologically harmful.
Blooms – toxic red tides
82
Describe an example of a dinoflagellate that is ecologically important.
Photosynthetic symbionts of coral
83
Ciliate
Use cilia for locomotion and feeding
Fast-moving
Most predators on bacteria or small protists
84
Give an example of a ciliate. What do ciliates use their cilia for?
Paramecium - Movement
85
What kind of nutrition do Euglena have? What does Euglena use its eyespot and light detector for?
Mixotroph
Eyespot = stigma
Blocks photoreceptor at base of flagella
For phototaxis to detect predators
86
What kind of pseudopods do amoebozoans have?
Lobe-shaped pseudopods
87
What is different about the cell structure of amoebas and slime molds?
Multiple nuclei
88
What do amoebas and slime molds use pseudopods for?
Movement
89
Xerophile
Dry
90
Alkaphile
Basic
91
Thermopile
Hot
92
What are two important roles that cyanobacteria played in the evolutionary history of life?
A cyanobacteria was engulfed and created photosynthetic eukaryotes
A cyanobacterium was engulfed by a eukaryote and became genetically integrated as a heritable photosynthetic organelle, or plastid
93
Cyanobacteria are an important group of bacteria. What are two ecological roles they play?
They form a component of the base of the aquatic food chain, and their photosynthetic activity aerates the habitat.
94
Gram stain procedure step 1 why are all the bacteria purple?
A thin coat of purple stain was added to the bacteria
95
Gram stain procedure step 2 why are all the bacteria purple?
Iodine was added to the bacteria but the stain was not removed
96
Gram stain procedure step 3, why are some of the bacteria now clear?
The cells were decolorized with acetone or ethanol
97
Gram stain procedure step 4, why are some of the bacteria now pink?
Those were Gram Negative bacteria colored by counter stain
98
Other than evolution, what is a second way that a bacteria may acquire a new beneficial trait?
They can acquire them from DNA or chromosomes of other species through plasmid transfer
99
Why are bacteria capable of evolving rapidly? Use the words mutation and natural selection, and generation time in your answer.
100
List the derived traits of plants
separate land plants from green algae
1. Waxy cuticle
2. Stomata
3. Multicellular, dependent embryos
4. Spores produced in sporangia
5. Apical meristems
101
Explain the purpose of a cuticle
prevent desiccation
102
Explain the purpose of stomata
allow CO2 and O2 exchange in air
103
What is the dispersal stage of seedless plants
Spores
104
Why do seedless plants depend on moist environments for reproduction
Sperm swims through water to fertilize eggs and other reproduction methods
105
What is the most common example of a bryophyte
Moss
106
Why are mosses short
No vascular systems
107
List the derived traits of vascular plants
Vascular tissues called xylem and phloem
Well-developed roots and leaves
108
What are two reasons that vascular tissue allowed vascular plants to grow tall
Transport water far from ground
Lignin in vascular tissue provides structural support
109
___________________ is the vascular tissue that transports water, while __________________ transports sugars
Xylum and phloegm
110
What are three purposes of roots
-anchor vascular plants
-absorb water and minerals from the soil
-store organic molecules
Roots contain vascular tissue
---Rhizoids DO NOT contain vascular tissue and are only for support
111
What is the primary purpose of leaves
organs that increase the surface area for photosynthesis
112
What is the most common example of seedless vascular plants
Ferns
113
Gametophyte
the sexual phase in the life cycle of plants that contains one set of chromosomes
114
Haploid
something that contains one set of chromosomes
115
Diploid
something that contains two sets of chromosomes
116
Sporangia
multicellular organs in sporophyte where spores are produced
117
Sporophyte
Diploid plants
118
Spores
the dispersal stage in seedless plants
119
Meristems
a region of plant tissue, found chiefly at the growing tips of roots and shoots and in the cambium, consisting of actively dividing cells forming new tissue
continual growth apical (apex) meristems
120
Grade vs Clade
Grade = collection of organisms that share key biological features (but not necessarily monophyletic clade)
121
Bryophyte
the earliest lineages to diverge from the common ancestor of land plants
122
Two types of bryophyte
mosses, liverworts
123
Bryophytes have rhizoids
Root-like structures
For anchoring,
Not for water and mineral absorption
No vascular tissue
124
What part of the bryophyte's structure makes the eggs and sperm
the green part that is photosynthetic
125
What part of moss is the sporangia for making spores for dispersal
The stalk-like structures
126
Bryophytes habitats
must live in moist habitats
127
Liverworts
~ 9,000 species
Tiny 2-20 mm wide
Has little gemmae cups in the 'leaves' that help reproduction
128
Liverworts reproduction
Asexually through Fragmentation and gemmae cups
129
Mosses traits
~ 15,000 species
Asexual reproduction via fragmentation
130
Moss structure
a sporangium on a stalk
Photosynthetic makes eggs, sperm
131
Differences between mosses and liverwort
Mosses found in more habitats than liverworts
More tolerant of desiccation (can rehydrate)
Phenols absorb UV
132
Peat
Sphagnum moss in wetlands
Decomposition very slow
Submerged, low temp, low O2, acidic
Accounts for ¼ of all carbon stored in soils, land plants
133
Peat facts
Peat covers 3% of earth’s surface – store 25% of earth’s soil/plant carbon
accumulates faster than decomposes
1.5-2.3 m thick
134
Peat climate change issues
Global warming – peat bogs dry, air warms
increases decomposition, releasing CO2
135
Charophytes
Freshwater algae
136
Plants evolved from what era
Paleozoic era from green algae after Cambrian explosion
137
Fossil evidence indicates that plants were on land at least 470 million years ago
Fossilized spores
Fossilized sporophyte tissue
138
Reproductive stages of multicellular, dependent embryos in plants
Egg retained in adult plant
Sperm swim to egg
Sperm fertilizes egg inside female
Diploid zygote develops into multicellular diploid embryo within tissues of female gametophyte
---Protection
---Nutrients transferred from parent to embryo
139
Meristems
a region of plant tissue, found chiefly at the growing tips of roots and shoots
cells from the apical meristems differentiate into various tissues
140
The closest relatives of the land plants
Green algae
141
Bryophyte
a group of land plants, sometimes treated as a taxonomic division, that contains three groups of non-vascular land plants: the liverworts, hornworts and mosses
142
Rhizoids
found in bryophytes
root-like structures for anchoring,
---Not for water and mineral absorption
---No vascular tissue
143
Reproductive stages of bryophytes
1. Spore dispersal
2. The spores grow into male and female gametophytes (n)
3. Sperm and eggs are released (n)
4. Sperm swims through water to fertilize an egg to create a zygote (2n)
5. An embryo forms (2n)
6. Grows into a sporophyte (2n) that mature
144
Fragmentation
Small pieces of moss "stems" or "leaves" are often scattered by the wind, water or animals. If a moss fragment reaches a suitable environment, it can establish a new plant.
144
Multicellular, dependent embryos
Where are they found?
Inside of the adult plant
145
Fossils of vascular plants date
425MYA
145
Bryophytes prominent vegetation how many years ago
100MYA
145
Lignin
vascular tissue that provides structural support
145
Apical meristems are responsible for continuous growth. What kind of cell division happens here?
Mitosis
146
Xylem
conducts most of the water and minerals
one way
no cell walls
147
Phloegm
distributes sugars, amino acids, and other organic products
two way
cell walls with perforation
148
What were the giant seedless vascular plants and during what era?
Horsetails
Devonian and Carboniferous
149
What did the first forests do?
removed CO2 from the atmosphere, global cooling at the end of the Carboniferous period
plants of Carboniferous forests eventually became coal
150
Horsetails
Diverse during the Carboniferous period, but are now restricted to the genus Equisetum
Sporangia clusters in cones, make spores
Live in water-logged soils
151
Ferns
The most widespread seedless vascular plants, with more than 12,000 species
They are most diverse in the tropics but also thrive in temperate forests
152
Rhizomes
underground stems for asexual reproduction
153
How do rhizomes differ from rhizoids?
Rhizoids vary from rhizomes in the fact that rhizoids are root-like structures emerging from the epidermal cells of the bryophytes, while rhizomes are root-like modified and underground altered stems
154
Fiddleheads
New fern shoots emerge from the rhizome curled up
155
Sporangia in ferns
found in clusters called “sori” (singular “sorus”) on the underside of leaves
one sorus = many sporangia
156
Fern reproduction
1. A mature fern (2n) releases spores (n) from sporangium in the sorus
2. The spore grows to release a flagellated sperm (n) and egg (n)
3. The sperm swims to the egg to fertilize it into a zygote (2n)
4. The zygote grows into a young gametophyte
5. The gametophyte grows into a new sporophyte (fern)
157
Seed plants first evolved in what period?
Carboniferous period
158
What organisms were dominate in the Carboniferous period?
forests dominated by seedless vascular plants
amphibians dominant
159
Derived traits of seed plants
Pollen grains make sperm
Eggs are made in ovules
Ovules become seeds
160
Pollen grains
A single cell containing two male gametes. Once mature, the anther splits open and pollen is released.
161
Ovules
Cells that produce egg - the part of the ovary of seed plants that contains the female germ cell and after fertilization becomes the seed
162
Integument
a tough outer protective layer, especially that of a plant that protects the ovule
163
Pollination
transfer of pollen (n) to part of plant containing ovule
pollen tube grows into ovule, discharges sperm
164
Fertilization
when sperm fuses with egg
165
Seed formation
An ovule becomes a seed after the egg is fertilized
166
Seeded plant reproduction
1. An unfertilized ovule releases a pollen grain (n)
2. The pollen grain enters a pollen tube and releases sperm (n)
3. The sperm fertilizes the egg to form a zygote (n)
4. This grows into an embryo (2n) and the ovule is fertilized
5. Integument becomes the seed coat
6. Seed contains embryo & food supply in protective seed coat
167
Seeds are the what stage for seed plants
Dispersal
168
Advantages of seeds
Can be dispersed long distances
Can remain dormant (protective coat)
Germination triggered by optimal environmental conditions
--temp, water, O2, light/dark, fire, etc
Contain food supply for seedling growth after germination (NOT food for seed!
Seed is dormant!!!)
169
Gymnosperm
seeds exposed on modified leaves
usually cones (aka strobili)
dominant when reptiles were dominant land vertebrates
170
Four gymnosperm phyla
Cycadophyta
Ginkgophyta
Gnetophyta
Coniferophyta
171
Cycadophyta
Very large cones
Separate male and female plants
Very tough, palm-like leaves
Abundant w/ dinosaurs
172
Ginkgophyta
1 species, Ginkgo biloba
Fan-shaped leaves
Separate male and female trees
173
Coniferophyta
Needle-like leaves or scale-like leaves
Most evergreen
Conifer and evergreen are NOT synonyms
174
Adaptations of coniferous trees
Needle-like leaves – adapted for harsh, cold conditions
Evergreen foliage
Conical shape
175
Pine (Gymnosperm) life cycle
1. A mature sporophyte (2n) grows an ovulate cone and pollen cone
2. The pollen cone releases microsporangia where pollen (male gametophytes n) is made
3. Pollen releases sperm
4. The ovulate cone contains ovules where eggs are made.
5. Conifers are wind pollinated.
6. The Microsporangium releases pollen grains (n).
7. Pollen tube slowly forms, grows toward ovule.
8. Sperm swims down tube to egg in ovule
fertilization! This can take a year before fertilization!
9. A zygote than embryo (2n) forms with a seed coat sounding it and food reserves for it.
10. The embryo undergoes meiosis in the seed.
11. The seed eventually grows into a sapling then mature plant (2n)
176
Gnetophyta
Angiosperm-like features: vessel elements, double fertilization, fruit-like ovule coverings
Dioecious. Female plants have covered ovules, while male plants have pollen cones.
