Module 1 Flashcards
1
Q
What are the two main types of cells?
A
Prokaryotic cells and Eukaryotic cells
Prokaryotic cells include Bacteria and Archaea, while Eukaryotic cells belong to the Eukarya domain.
2
Q
What are the two main domains of Prokaryotic cells?
A
Bacteria and Archaea
Bacteria includes the vast majority of prokaryotic species, while Archaea shares traits with both bacteria and eukaryotes.
3
Q
Where is the location of DNA in Prokaryotic cells?
A
Concentrated in a nucleoid
Prokaryotic cells do not have a nucleus.
4
Q
Where is most of the DNA located in Eukaryotic cells?
A
In the nucleus
Eukaryotic cells have a defined nucleus that houses the majority of their genetic material.
5
Q
Do Prokaryotic cells have organelles?
A
Absent in most cells
Prokaryotic cells are generally simpler in structure.
6
Q
Do Eukaryotic cells have organelles?
A
Yes
Eukaryotic cells contain various organelles that perform specific functions.
7
Q
How do Prokaryotic cells generally compare in size to Eukaryotic cells?
A
Prokaryotes are generally smaller
Eukaryotic cells are much larger due to their more complex functions.
8
Q
Fill in the blank: Prokaryotic cells are generally ______ compared to Eukaryotic cells.
A
smaller
9
Q
True or False: Prokaryotic cells have a nucleus.
A
False
Eukaryotic cells have a nucleus, not a nucleoid.
10
Q
What features are the same between prokaryotes and eukaryotes?
A
- Cell membrane
- Cytoplasm
- Ribosomes
- Genetic material
Archaea also have their own unique characteristics.
11
Q
What 2 features do eukaryotic cells have that differ to prokaryotic cells?
A
- membrane-based organelles
- a nucleus
12
Q
What does the term ‘prokaryote’ mean?
A
Before nucleus
Derived from ‘Pro’ meaning before and ‘Karyote’ meaning nucleus.
13
Q
What are the key features of a prokaryote?
A
- DNA in a singular circular molecule
- All common features of ALL cells
- Many have extra-cellular DNA in the form of plasmids, capsule, and fimbriae
Prokaryotes do not have a nucleus or internal compartmentation.
14
Q
What are the characteristics of prokaryotic DNA?
A
- Singular circular molecule
- Not enclosed in a nucleus
- Located in the cytoplasm
This structure is often referred to as a nucleoid.
15
Q
What is metabolic cooperation in prokaryotes?
A
Occurs between different prokaryotic species in biofilms, allowing environmental resource sharing
Cells in a biofilm secrete signaling molecules and create channels for nutrient and waste exchange.
16
Q
How do prokaryotes attach to surfaces?
A
Fimbriae or capsule
Fimbriae are hair-like appendages that help adhere to various surfaces.
17
Q
How do prokaryotes move?
A
Through flagella embedded in the cell membrane and walls
Approximately half of bacterial cells are motile, primarily due to flagella.
18
Q
What is binary fission?
A
The method of prokaryote reproduction involving splitting into two clones (no mitosis or gene mixing)
This process does not involve mitosis, sex, or gene mixing.
19
Q
What is the typical generation time for prokaryotes?
A
1-3 hours
Prokaryotic populations can rapidly respond to favorable conditions through mutations.
20
Q
What are plasmids in prokaryotes?
A
Extra-chromosomal DNA used for gene cloning, transfer, and manipulation
Plasmids are often involved in genetic engineering.
21
Q
What is conjugation in prokaryotes?
A
The transfer of genetic material between two temporarily joined prokaryotic cells
A donor cell attaches via a pilus to transfer DNA, contributing to genetic variation.
22
Q
What is transformation in prokaryotes?
A
Assimilation of external DNA (i.e from the environment) by a cell, resulting in a genotype change
Can lead to horizontal gene transfer when DNA is from a different species.
23
Q
What is transduction in prokaryotes?
A
Transfer of bacterial DNA via viruses between different bacteria
This process can also result in horizontal gene transfer.
24
Q
True or False: Horizontal gene transfer has played a key role in the evolution of prokaryotes.
A
True
It allows for genetic variation and adaptation among prokaryotic populations.
25
What is a biofilm?
A layer of surface-coating bacteria that create colonies that share resources and expel waste
26
What characteristic enable prokaryotes to reach huge population sizes and thrive in diverse environments?
1. small size
2. rapid reproduction (=rapid evolution)
3. diverse adaptations
27
What is fimbriae?
Hair-like appendages that extend from the cell membrane and allow prokaryotes to adhere to various surfaces
28
What is a capsule?
A sticky outer layer allowing prokaryotes to cling to surfaces
29
True or False: Most motile bacteria have flagella?
True
30
True or False: Eukaryotes do not have flagella.
False (they can!)
31
Does binary fission result in 2 daughter cells with mixed genes?
No, they are both exact clones of the parent cell.
32
Do prokaryotic cells typically have more or less DNA than eukaryotic cells?
Less
33
What are 3 ways that prokaryotes obtain genetic variation?
1. Conjugation
2. Transformation
3. Transduction
34
What is the benefit of conjugation for prokaryotes?
Genetic variation
35
What is nitrogen fixation?
The process of converting atmospheric nitrogen into a form that plants and animals can use.
36
What is the conversion process in nitrogen fixation?
Conversion of atmospheric nitrogen (N2 gas) to ammonia (NH3).
37
Which organisms can perform nitrogen fixation?
Some prokaryotes can perform this process.
38
In what condition does nitrogen fixation occur?
The process can only occur in the absence of oxygen.
39
Give an example of a prokaryote involved in nitrogen fixation.
Rhizobium, which forms nodules on the roots of legumes.
40
Which type of bacteria can form associations with plants to help with nitrogen fixation?
Some plants form associations with cyanobacteria or actinobacteria.
41
Fill in the blank: Nitrogen fixation involves the conversion of atmospheric nitrogen to _______.
ammonia (NH3)
42
True or False: Nitrogen fixation can occur in the presence of oxygen.
False
43
What are mutualistic bacteria also known as?
Happy bacteria
44
Why is human (and other vertebrate) well-being dependent on mutualistic prokaryotes?
They provide positive benefits for both parties (e.g. digestion, anti-biotics)
45
How many species of bacteria are typically found in the human intestines?
500-1000 species
46
What do some bacteria secrete to trigger the human intestine to build blood vessels?
Chemical signals
47
What are the three main ways pathogenic bacteria induce symptoms?
* Direct parasitic effects (eg. destruction of tissue)
* Toxins (e.g. food poisoning)
* bacterial diseases (e.g. anthrax, strep)
48
What are exotoxins?
Proteins secreted by certain bacteria and other organisms
49
What are endotoxins?
a type of bacterial toxin found in the outer membrane of Gram-negative bacteria, and are released when these bacteria die or are disrupted.
50
Name a bacterial disease that produces toxins.
Anthrax
51
What can happen if Streptococcus bacteria grows too quickly?
Infection can occur
52
What is the natural role of antibiotics produced by microbes?
Reduce cellular competition for resources
53
Which process does penicillin inhibit?
Wall synthesis
54
What is one consequence of excessive antibiotic use?
Selection for resistance
55
What crucial role do prokaryotes play in the biosphere?
* Chemical recycling
* Ecological interactions
56
How do prokaryotes function as decomposers?
Breaking down dead organisms and waste products
57
What impact do prokaryotes have on the global nitrogen cycle?
They can increase or decrease nutrient availability for plants/other organisms
58
What percentage of all human diseases are caused by pathogenic bacteria?
About half
59
What are the two types of toxins produced by pathogenic bacteria?
* Exotoxins
* Endotoxins
60
How are exotoxins released?
FIX THIS
61
What are some uses of bacteria in research and technology?
* Converting milk to cheese and yoghurt
* Production of beer and wine
* Modifying bacteria to produce vitamins, antibiotics, hormones
* Reducing petroleum
62
True or False: Exotoxins are only released when the bacteria die and their cell walls break down.
False (exotoxins secrete while alive endotoxisn secrete upon death)
63
What processes can be inhibited with the use of antibiotics?
* wall synthesis
* protein synthesis
64
True or False: Half of pathogenic prokaryotes are bacteria.
False (all are!)
65
What is the Endosymbiont Theory?
Certain organelles in eukaryotic cells, like mitochondria and chloroplasts, originated as free-living prokaryotes that were engulfed by an ancestral eukaryotic cell, evolving into a symbiotic relationship
## Footnote
Can be beneficial for both cells, or detrimental to one but beneficial to the other
66
What occurs when two prokaryote cells interact according to the Endosymbiont Theory?
One gets engulfed by the other, forming a host cell
67
How did mitochondria come to be in eukaryotic cells?
a eukaryotic cell engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host eukaryote, gradually developing into a mitochondrion
68
How did chloroplast come to be in plant cells?
A photosynthetic cyanobacterium was engulfed by a primitive eukaryotic cell
69
What is suggested about mitochondria and chloroplasts in relation to prokaryotic cells?
They were once free-living prokaryotic cells that were engulfed by a proto-eukaryotic cell
70
What are the key pieces of evidence for the (serial) Endosymbiont theory?
Mitochondria and chloroplasts
* Have a double membrane
* Have their own set of genetics
* Have their own ribosomes
* Can replicate independently from nuclear DNA
* Are autonomous organelles that grow and reproduce within the cell
* Ancestors were prokaryotes
71
What is the approximate number of core genes in mitochondria and chloroplasts?
~4,000 core genes
72
What fraction of core genes are the same across all types of eukaryotes?
~⅕
73
What is the origin of 'information' genes in core genes?
Archaeal origin for DNA replication, transcription, translation
74
What is the origin of metabolic process genes in core genes?
Bacterial origin: Metabolic processes & membranes
75
What percentage of unique genes is found between different eukaryotic groups?
~30%
76
77
78
What is a eukaryote?
Any cell or organism that possesses a clearly defined nucleus
## Footnote
Eukaryotes are characterized by their complex cellular structure.
79
What was the original host cell type for eukaryotes?
Archaeon host cell with an evolved nucleus.
## Footnote
This suggests that eukaryotes have a unique evolutionary origin.
80
What process contributed to the genetic diversity in eukaryotes?
Horizontal gene transfer.
## Footnote
This process allows for the exchange of genetic material between different organisms.
81
What maintains the structure of eukaryotic cells?
Complex cytoskeleton.
## Footnote
The cytoskeleton is essential for cell shape and movement.
82
What are the characteristics of proteins in eukaryotic cells?
Complicated.
## Footnote
This complexity contributes to the diverse functions of proteins in eukaryotic cells.
83
What type of chromosomes do eukaryotes have?
Multiple linear chromosomes housed in a nucleus.
## Footnote
This is in contrast to prokaryotes, which typically have a single circular chromosome.
84
What advanced systems do eukaryotes utilize for communication?
Advanced signalling cascades.
## Footnote
These signalling pathways are crucial for cellular responses and interactions.
85
Name three examples of eukaryotes.
* Land plants
* Fungi
* Animals
## Footnote
Eukaryotes encompass a wide variety of life forms.
86
What are the key features of eukaryotic cells?
* membrane-bound organelles
* mitochondria (plants also have chloroplast)
* cytoskeleton
* linear chromosomes in a nucleus
87
What is the cytoskeleton made up of?
Protein fibers and filaments that can move
88
What types of cells have a cytoskeleton?
Eukaryotes and bacteria
89
What are the two main functions of the cytoskeleton?
* Support
* Motility
90
What is the role of microtubules in the cytoskeleton?
Hollow rods composed of tubulin proteins that help to change cell shape and support the cell
91
What cellular structures are microtubules connected to?
Flagella and cilia
92
How do microtubules assist motor proteins?
They serve as tracks along which motor proteins can move
93
What is the function of microfilaments?
To bear tension and help support the cell’s shape
94
What is another name for microfilaments?
Actin filaments
95
What role do myosin filaments play in muscle cells?
They cause muscle contraction
96
In which organism are microfilaments important for movement?
Amoeba
97
What is an important role of microfilaments in cell division?
They are important in the final stage of cell division
98
What are intermediate filaments specialized for?
Bearing tension
99
Fill in the blank: The cytoskeleton provides _______ to the cell.
mechanical support
100
True or False: The cytoskeleton only exists in eukaryotic cells.
False
101
What do chromosomes carry?
Genes in the form of DNA
## Footnote
Heritable information archived in DNA molecules
102
What is the structure of DNA?
Sequence of bases (A, T, G, C)
## Footnote
RNA is used as a working copy
103
What are lysosomes?
Digestive compartments that digest molecules
## Footnote
A membranous sac used by many eukaryotic cells for intracellular digestion
104
What is the role of vacuoles?
Large vesicles derived from the endoplasmic reticulum and Golgi apparatus that transport solutes
## Footnote
Integral part of endomembrane system, selective in transporting solutes
105
What is a key difference between animal and plant cells?
Plant cells have a cell wall, animal cells do not
## Footnote
Unlike plant cells, animal cells do not have a cell wall
106
What is metabolism?
Coordinated chemical pathways for transformation of substances and generation of energy
## Footnote
Catalyzed by enzymes
107
What does reproduction involve?
Production of new cells
## Footnote
Structures and processes necessary for new cell formation
108
What is the significance of two parents in reproduction?
They give rise to offspring with a unique combination of genes
## Footnote
Related to sex and sex differentiation phenomena occurring only in eukaryotes
109
True or False: Sex differentiation occurs in both prokaryotes and eukaryotes.
False (only in eukaryotes)
## Footnote
Sex differentiation phenomena occur only in eukaryotes
110
What is the structure of the Endoplasmic Reticulum (ER)?
Consists of a network of membranous sacs (cisternae)
## Footnote
The ER membrane is continuous with the nuclear envelope.
111
What are the functions of Rough ER?
* Makes secretory proteins
* Grows membranes for its own cell
112
What are the key characteristics of Smooth ER?
Has no ribosomes and functions in diverse metabolic processes including:
* Synthesis of lipids
* Metabolism of carbohydrates
* Detoxification of drugs and poisons
* Storage of calcium ions
113
What is the role of the nuclear envelope?
Encloses the nucleus, separating its contents from the cytoplasm
114
What is the significance of large pores in the nuclear envelope?
Ringed with proteins, they allow transport between the nucleus and cytoplasm
115
What does the nucleus contain?
Chromosomes (DNA) and is the site of transcription (DNA to RNA)
116
What is the structure of the cell membrane?
Double phospholipid layer that is semipermeable around the outside of the cell
117
How do membranes maintain fluidity?
Molecules can flip horizontally and vertically; a membrane must be fluid to allow movement of membrane proteins
118
What effect does temperature have on membrane fluidity?
A membrane solidifies as temperatures decrease
119
What is the role of cholesterol in the membrane?
Acts as a fluidity buffer, resisting changes in membrane fluidity caused by temperature changes
120
What are ribosomes?
Tiny complexes that make proteins according to DNA instructions
121
What are the two types of ribosomes?
* Free ribosomes (suspended in the cytosol)
* Bound ribosomes (attached to the outside of the endoplasmic reticulum)
122
What is the function of the Golgi Apparatus?
Acts as a shipping and receiving warehouse, involved in:
* Receiving transport vesicles from the ER
* Sorting material
* Shipping material via transport vesicles
* Some manufacturing
123
What are two key features of mitochondria?
*a double membrane
* its own circular DNA and ribosomes
124
What is the primary function of mitochondria?
Site of cellular respiration (energy conversion)
125
Fill in the blank: The Golgi Apparatus is formed from vesicles that have migrated from the _______.
endoplasmic reticulum
126
True or False: Ribosomes are membrane-bound organelles.
False
127
How many membranous layers does a nuclear envelope have?
2
128
What is the primary cell wall made out of?
Cellulose and pectin
129
What is the function of the middle lamella?
Glues the adjacent cells together
130
What happens to the cell wall when the cell has stopped growing?
Strengthens its walls by secreting hardening substances or adding a secondary cell wall
131
List the 3 purposes of the cell wall.
* Protects the plant cell
* Maintains its shape
* Prevents excessive uptake of water
132
What type of membrane do chloroplasts have?
Double membrane
133
Do chloroplasts have their own set of genetics?
Yes
134
What can chloroplasts replicate independently from?
Nuclear DNA (as they have their own set of genetics and own ribosomes)
135
What is the site of photosynthesis in plant cells?
Chloroplast
136
What is the main function of chloroplasts?
Converts solar energy to chemical energy by absorbing sunlight and synthesizing sugars
137
Are chloroplasts usually larger or smaller than mitochondria?
Larger
138
What pigments are tightly arranged in chloroplasts for photosynthesis?
Chlorophyll
139
What are the 3 parts of a plant cell wall?
* Primary wall
* secondary wall
* middle lamella
140
True or False: A plant cell wall is relatively thin and inflexible.
False (it is thin, but it is flexible)
141
Why do cells reproduce?
To support growth, renewal, and repair of tissues.
142
What are chromosomes?
Long DNA molecules, also known as chromatin, that are double helices of DNA.
143
What is the centromere?
The pinch point where sister chromatids are connected.
144
What are sister chromatids?
Joined copies of the original chromosome (2 identical strands of DNA).
145
What are the stages of the cell cycle?
* Interphase
* Mitosis.
146
What happens during G1 phase of interphase?
Cell performs normal functions, producing organelles, proteins, enzymes.
147
What occurs in the S phase of interphase?
DNA is replicated to form two copies of each chromosome, resulting in sister chromatids joined at the centromere
148
What is the longest stage of a cell's life?
Interphase.
149
What occurs during G2 phase of interphase?
Cell growth continues, organelles replicate, and centrosomes form.
150
What is the aim of mitosis?
To make identical cells by separating duplicated chromosomes.
151
What happens in prophase?
* Cytoskeleton put in place (spindle microtubule)
* DNA condenses
* Kinetochore put in place
152
What is a kinetochore?
Proteins that attach spindles to the centromere of the chromosome.
153
What occurs during metaphase?
Paired chromatids are aligned in a central plane for separation.
154
What happens during anaphase?
Sister chromatids are pulled towards opposite poles of the spindle.
155
What is the process of telophase?
* Dismantling of the spindle
*rebuilding of the new nuclei and nuclear envelopes
156
What occurs at the end of mitosis?
Two nuclei identical to the starting cell are formed.
157
What is cytokinesis?
Division of cytoplasm and formation of two daughter cells.
158
How does cytokinesis occur in (most) animals?
The mother cell is pinched in two at the cleavage furrow.
159
How does cytokinesis occur in plants?
A cell plate forms to divide the mother cell into two daughter cells.
160
How does cytokinesis occur in fungi?
During anaphase, one part of the chromosome is dragged out to a budding membrane, then splits to form two cells.
161
How long can human cells take to divide?
9-24 hours.
162
What is condensation (in relation to DNA)?
The coiling and folding of DNA
163
What joins sister chromatids?
A centromere
164
What are the stages of interphase?
*G1
*S
*G2
165
What are the stages of mitosis?
* Prophase
* Metaphase
* Anaphase
* Telophase
* Cytokinesis
166
What happens to mitochondria during the G1 & G2 phases of cell division?
The existing mitochondria duplicate themselves.
## Footnote
Mitochondria have their own DNA and replicate independently by fission.
167
What is the outcome of mitochondrial replication during interphase?
End up with double the amount of mitochondria
168
During which phase do mitochondria move to each end of the cell?
Cytokinesis phase
169
What is the purpose of mitochondria moving during cytokinesis?
To ensure the right amount in each daughter cell
170
What type of DNA do prokaryotes have?
Single circular DNA molecule
171
What is the process of reproduction in prokaryotes called?
Binary fission
172
What are the steps involved in binary fission?
* DNA is replicated
* DNA moves to either end of the cell
* Cell gets bigger
* New membrane forms
173
What is a protist?
Eukaryotes that are NOT multicellular plants, animals, or fungi
## Footnote
Includes diverse organisms that may live in colonies and can reproduce sexually, asexually, or both.
174
What are the typical characteristics of protists?
* Usually unicellular
* usually has chloroplasts
* has a nucleus
* may have flagella
* may have a cell wall or specialized cytoskeleton
## Footnote
Protists are often diverse and can vary significantly in structure and function.
175
What types of protists are there?
* Plant-like protists (Algae)
* Animal-like protists (Protozoa)
* Fungi-like protists (Slime moulds)
## Footnote
These classifications indicate varying relationships to other eukaryotes.
176
How do protists reproduce?
Sexually, asexually, or both
## Footnote
Reproductive methods can vary widely among different protists.
177
Where do protists fit in the eukaryote phylogeny?
Part of a phylogenetic tree with a root that is not known
## Footnote
The root is hypothesized to be located between the unikonts and other eukaryotes.
178
What are the four supergroups of eukaryotes?
* Excavata
* SAR clade
* Archaeplastida
* Unikonta
## Footnote
These groups represent fluctuating knowledge and theories in eukaryotic classification.
179
True or False: Most protists are multicellular.
False
## Footnote
Most protists are unicellular.
180
Fill in the blank: Some protists can be as small as _______.
prokaryotes
## Footnote
This highlights the small size range of some protists.
181
What do you call a plant-like protist?
Algae
182
What do you call an animal-like protist?
Protozoa
183
What do you call a fungi-like protist?
Slime moulds
184
Where do protists primarily live?
* Mostly aquatic
* in soil
* in other organisms (many are parasitic)
## Footnote
Many protists are parasitic.
185
What are the two parts of the protist life cycle?
* Asexual reproduction
* Sexual reproduction
## Footnote
Asexual reproduction involves mitotic cell divisions; sexual reproduction is associated with changing conditions.
186
What type of reproduction do protists use during favorable conditions?
Asexual reproduction (mitosis)
## Footnote
This involves mitosis, creating identical clones of parent cells.
187
What happens during sexual reproduction in protists?
Mature cell forms gametes, which combine to form a zygote
## Footnote
The zygote can enter a cyst state until conditions are favorable.
188
What are the four reproductive life cycle types in protists?
* Haploid
* Diploid
* Dikaryotic
* Alternate
## Footnote
These types vary based on the number of chromosome sets.
189
What is a haploid organism?
An organism with 1 set of chromosomes
## Footnote
This contrasts with diploid organisms, which have 2 sets.
190
What is a diploid organism?
An organism with 2 sets of chromosomes
## Footnote
This is the opposite of haploid organisms.
191
What does dikaryotic mean?
Having 2 haploid nuclei per cell
## Footnote
This is a unique reproductive state in some protists.
192
True or False: All protists have the same reproductive strategies.
False
## Footnote
The only generalization is the diversity of reproductive strategies.
193
What is the significance of diversity in protist reproduction?
Reflects evolutionary experimentation
## Footnote
It indicates the adaptability and complexity of protist life cycles.
194
What are the two primary modes of motility in organisms?
Flagella and cilia
## Footnote
Flagella are long and few in number, while cilia are short and many.
195
What is pseudopodia?
structures observed on certain unicellular organisms and some animal cells that function as a way of locomotion and a way to capture and engulf particles
## Footnote
They allow organisms like amoebas and slime moulds to manipulate their membrane to engulf particles.
196
Define autotrophic nutrition.
Nutrition where organisms produce their own food through photosynthesis
## Footnote
Examples include algae, which photosynthesize using sunlight.
197
What functional term is used for organisms that photosynthesize but are not true plants?
Algae
## Footnote
Algae is the functional term for any photosynthetic organisms outside of true plants.
198
What is the process of photosynthesis?
Conversion of carbon dioxide and water into carbohydrates using sunlight
## Footnote
This process produces oxygen as a byproduct.
199
What is endosymbiosis?
A process where one organism engulfs another, leading to a symbiotic relationship
## Footnote
This process is crucial for the origin of eukaryotes, which developed mitochondria from engulfed bacteria.
200
What occurs during primary endosymbiosis?
A lineage of heterotrophic eukaryotes acquires a photosynthetic cyanobacterium
## Footnote
This event leads to the evolution of plastids.
201
What are the two lineages of photosynthetic protists that arose from primary endosymbiosis?
Red algae and green algae
## Footnote
These lineages evolved from plastid-bearing ancestors.
202
What happens during secondary endosymbiosis?
Red and green algae are ingested by heterotrophic eukaryotes and become endosymbionts
## Footnote
This process further diversifies the evolutionary lineage of photosynthetic organisms.
203
What are 2 key differences between flagella and cilia
Flagella are long and few
Cilia are short and many
204
What are 2 examples of organisms who use pseudopodia?
* Amoebas
* Slime moulds
205
What are the two main types of heterotrophic organisms?
Animal-like and fungus-like
## Footnote
Animal-like organisms consume other cells, while fungus-like organisms absorb nutrients.
206
What is the method of nutrition used by fungus-like organisms such as Oomycetes?
Absorptive nutrition
## Footnote
Oomycetes release enzymes to break down larger molecules for absorption.
207
What are some examples of fungus-like organisms?
* Water moulds
* White rust
* Downy mildew
## Footnote
These organisms utilize absorptive nutrition.
208
What are dinoflagellates known for?
Forming large blooms called red tides
## Footnote
Dinoflagellates can cause toxic blooms leading to shellfish poisoning.
209
What are the key features of dinoflagellates?
* 2 parts to the cell
* Flagella around the center
## Footnote
These features help dinoflagellates in movement and bloom formation.
210
What are diatoms primarily known for?
Being a common component of phytoplankton
## Footnote
Diatoms are photosynthetic and can absorb CO2.
211
What is a notable characteristic of diatom cell walls?
Glass-like and composed of two halves
## Footnote
This structure is similar to a box and is significant in their classification.
212
What is diatomaceous earth used for?
Dating atmospheric changes and filtering
## Footnote
Diatomaceous earth contains fossilized diatoms and serves both scientific and practical purposes.
213
What are the characteristics of brown algae?
* All multicellular
* Mostly marine
* Largest seaweeds
## Footnote
Brown algae include giant kelp, which is the longest organism on Earth.
214
What are the main parts of brown algae?
* Hold fast
* Stipe
* Blade
## Footnote
These parts serve functions similar to roots, trunks, and leaves in terrestrial plants.
215
Green algae is a close relative of which modern day organisms?
Land plants
## Footnote
Especially charophytes, which resemble the ancestors of today's land plants.
216
What is the life cycle of Plasmodium species in malaria?
Complex life cycle with sexual reproduction in mosquitoes and asexual reproduction in humans
## Footnote
This complexity is essential for the transmission and survival of the malaria parasite.
217
What are Giardia and Cryptosporidium known for?
Resistant cysts in water supplies
## Footnote
These cysts can survive drying and are spread through faecal contamination.
218
Fill in the blank: Malaria is caused by _______.
Plasmodium species
219
True or False: Diatoms are exclusively found in freshwater environments.
False
## Footnote
Diatoms are primarily found in marine environments as part of phytoplankton.
220
What is the method of nutrition used by Protozoa organisms?
Heterotrophic nutrition (engulfing)
221
What can dinoflagellates cause?
Toxic blooms (e.g. shell fish poisoning)
222
True or false: Diatoms metabolise via photosynthesis.
True
223
Is Brown Algae unicellular?
No (it is multicellular)
224
Is Green Algae unicellular?
It can be unicellular, colonial, or multicellular
225
Is cellular slime mould (Dictostelium) a fungi?
No
## Footnote
Cellular slime moulds are often mistaken for fungi but have evolved from unicellular ancestors.
226
What are the two parts of the life cycle of cellular slime mould?
Asexual and sexual
## Footnote
The life cycle includes both asexual reproduction for most of their life and a transition to sexual reproduction when conditions are challenging.
227
What happens to cellular slime moulds during tough conditions?
Switch to sexual production and aggregate
## Footnote
They migrate and aggregate to form a slug that undergoes sexual reproduction.
228
What is the plasmodium phase of slime mould?
Lives in soil as a single cell but can aggregate
## Footnote
The plasmodium phase allows for sexual reproduction when resources are low.
229
From what do animals possibly evolve?
Colonial protists similar to choanoflagellates
## Footnote
This collaboration may have led to the formation of tissues and larger systems in animals.
230
What are choanoflagellates?
Free-living unicellular and colonial flagellate eukaryotes
## Footnote
They are considered the closest living relatives of animals and share many genetic similarities.
231
What type of reproduction can choanoflagellates perform?
Sexual and asexual
## Footnote
They exhibit both forms of reproduction and live in colonies.
232
What ecological role do photosynthetic protists play?
They form the base of ecological food webs
## Footnote
They are crucial for maintaining ecological balance.
233
Give two examples of photosynthetic protists.
* Diatoms
* Dinoflagellates
## Footnote
These organisms are key contributors to aquatic ecosystems.
234
What are symbiotic protists?
Beneficial protists that form partnerships
## Footnote
Examples include photosynthetic dinoflagellates and wood-digesting protists in termites.
235
Name a parasitic protist that causes malaria.
Plasmodium
## Footnote
This is a well-known example of a harmful protist affecting human health.
236
Fill in the blank: Photosynthetic dinoflagellates are food-providing _______ partners of the animals that build coral reefs.
symbiont
## Footnote
They play a critical role in coral reef ecosystems.
237
What is a parasitic plant that causes sudden oak death?
Phytophthora Ramorum
## Footnote
This pathogen poses a significant threat to oak trees.
238
239
240
What are the common features of fungi?
* Have hyphae
* Have mycelium
* Reproduce via spores
* Heterotrophic (absorb nutrients)
## Footnote
None
241
What is the basic unit of fungi?
Hyphae
## Footnote
None
242
What are hyphae?
Filaments with cell walls containing chitin
## Footnote
Chitin differs from cellulose found in plants.
243
How do hyphae grow?
Extend the tips to grow longer and have a larger surface area
## Footnote
None
244
What are septa hyphae?
Cross-walls that divide hyphae into compartments (septum = singular)
## Footnote
Septum is the singular form.
245
What are the two types of hyphae?
* Septate hypha
* Coenocytic hypha
## Footnote
None
246
What characterizes coenocytic hypha?
Massive tubular, nebular cell with many nuclei
## Footnote
May have branches.
247
What is mycelium?
The body of a fungus, an interwoven mass of hyphae
## Footnote
Mushrooms are only a small part of the mycelium.
248
What do mushrooms represent in fungi?
The reproductive structures that release spores
## Footnote
Most of the mycelium is underground or in another substrate.
249
Fill in the blank: Fungi are _______ organisms that absorb nutrients.
heterotrophic
## Footnote
None
250
True or False: All parts of a fungus are visible above ground.
False
## Footnote
Most of the mycelium is underground.
251
What characterizes septate hypha?
* has cell divisions
* 1x nucleus per cell division
252
253
254
What type of nutrition do fungi use?
Heterotrophic (Absorptive) nutrition
## Footnote
Fungi secrete enzymes into their environment to break down complex molecules for nutrient uptake.
255
What is the role of saprotrophs in the environment?
Decomposition
## Footnote
Saprotrophs play a large role in breaking down dead organic matter.
256
What are moulds?
A growing form of fungus that develops in the shape of filaments
## Footnote
Moulds are multicellular and can be seen with the naked eye.
257
How do moulds reproduce?
Rapid growth via vegetative (asexual) reproduction and spores
## Footnote
Moulds can produce both sexual and asexual spores through airborne spores.
258
What ecological role do moulds serve?
Decomposers
## Footnote
Moulds are important for breaking down organic matter and contribute to carbon cycling.
259
What are mycotoxins?
Toxins found in the cell walls of some moulds
## Footnote
Mycotoxins can cause significant neurological impacts if ingested or inhaled by mammals.
260
What are the characteristics of yeasts?
Unicellular fungi that reproduce by budding or fission
## Footnote
Yeasts are important in food production and fermentation.
261
What is the most common shape of yeasts?
Oval
## Footnote
Yeasts appear as thready and white, commonly found on fruits and in various environments.
262
What is the primary method of reproduction in yeasts?
Budding
## Footnote
Yeasts reproduce asexually, often through a process known as budding.
263
What is the energy production method for yeasts?
Convert carbohydrates into carbon dioxide and alcohol (anaerobic fermentation)
## Footnote
This process is crucial for various fermentation processes.
264
Fill in the blank: Moulds develop as multiple tubular branches and are classified as _______.
Multicellular
265
True or False: Moulds can grow in both aerobic and anaerobic environments.
False (only aerobic)
## Footnote
Moulds are strictly aerobic and require oxygen for growth.
266
What are the common habitats for yeasts?
Widespread, often on berries and fruits, and inside the stomachs of mammals
## Footnote
Yeasts thrive in various environments, including moist areas.
267
What is a significant health concern associated with yeasts like Candida?
Infections
## Footnote
Yeasts can cause infections in humans, particularly in immunocompromised individuals.
268
What is a saprotroph?
Organism that feeds on dead organisms or their waste
269
270
271
What is reproduction in fungi usually by?
Spores
## Footnote
Spores can be formed asexually or sexually.
272
Define spores.
Small propagules that grow directly into a new organism.
273
What type of reproduction do spores undergo when formed from mitotic divisions?
Asexual reproduction.
274
What appearance do colonies of asexual spores often have?
Powdery appearance.
275
What type of reproduction do spores undergo when formed from fertilisation and meiosis?
Sexual reproduction.
276
What are the characteristics of spores?
* Mostly single-celled (May be septate)
* May be coloured
* May have special shapes to aid in dispersal
277
What is a fruiting body?
A large structure where spores, especially sexual spores, are formed.
278
What is the purpose of fruiting bodies?
Protection of spores (survival) and/or dispersal.
279
What is the main mechanism of spore dispersal?
Wind dispersal.
280
How do mushrooms assist in spore dispersal?
By elevating the spores above the ground.
281
What is rainsplash dispersal?
Spores are dislodged and carried by water drops and splashes.
282
How do stinkhorns disperse their spores?
By mimicking the smell of rotting meat to attract flies.
283
What role do mammals play in spore dispersal?
They disperse spores of symbiotic fungi via their faeces.
284
What are conidiophores?
Branching structures that produce haploid spores by mitosis.
285
What is the lifecycle of fungi characterized by?
Asexual or sexual reproduction.
286
Describe asexual reproduction in fungi.
Hyphae form branches with spores that disperse and germinate into a clone.
287
Describe sexual reproduction in fungi.
Mycelia with 2 mating types may be dikaryotic, forming diploid nuclei that undergo meiosis to produce spores.
288
What ecological role do fungi play as decomposers?
Carbon recycling and breaking down particles and nutrients.
289
What are mycotoxins?
Toxins produced by some fungi on contaminated grains that can cause health impacts.
290
What is mycorrhiza?
Mutually beneficial relationships between fungi and plant roots.
291
What are the two forms of mycorrhizae?
* Ectomycorrhizae
* Arbuscular mycorrhizae (endomycorrhizae)
292
What is a lichen?
A symbiotic relationship between fungi and algae or cyanobacteria.
293
What is the significance of lichens as bioindicators?
They indicate air quality.
294
Fill in the blank: Lichens are considered as one ______ organism.
[single]
295
True or False: Fungi can break down lignin into simple sugars.
True.
296
What are 2 examples of fruiting bodies?
* Mushroom
* Toadstools
297
What are 3 types of spore dispersal?
* Wind
* Rainsplash
* Animal
298
What is Ectomycorrhizae?
Where the fungi grows on the outside of the root and within the cell
299
What is Arbuscular mycorrhizae (aka: endomycorrhizae)?
Where the fungi grows on the surface of the root, between and within the cell walls, and within the cell
