2023 exam (MCQ)

which of the following describes the typical dinoflagellate nucleus (dikaryon)?

a. The dinoflagellate nucleus is unusual because it has permanently condensed chromatin, the genome is usually very large and the base 5-hydroxymethyl uracil can be prevalent

b. the dinoflagellate nucleus is unusual because the genome is usually very large and the base 5-hydroxymethyl uracil can be prevalent

c. the dinoflagellate nucleus is unusual because it has permanently condensed chromatin and the genome is usually very large

d. the dinoflagellate nucleus is unusual because it has permanently condensed chromatin, the genome is usually very large and the base 5-hydroxymethyl uracil can be prevalent

e. the dinoflagellate nucleus is unusual because it has permanently condensed chromatin and the genome is usually very large

the dinoflagellate nucleus is unusual because it has permanently condensed chromatin, the genome is usually very large and the base 5-hydroxymethyl uracil can be prevalent

if you want to conduct an experiment to study the effect of temperature on the growth rate and biochemical composition of microalgae, which would be a good bioreactor control strategy to choose?

a. batch

b. turbidostat

c. semi-continuous

d. fed-batch

e. chemostat

chemostat

which type of viruses commonly infect coccolithophores and mamiellophyceae?

a. RNA virsues about 0.1-0.2 microns in size

b. ssDNA viruses about 1-2 microns in size

c. dsDNA viruses about 0.1-0.2 microns in size

d. ssDNA viruses about 0.1-0.2 microns in size

e.dsDNA viruses about 1-2 microns in size

dsDNA viruses about 0.1-0.2 microns in size

diatoms II: which is the best description?

a. both Phaeodactylum and Thalassiosira are centric diatoms with a cylindrical cell profile and sometimes forms short chains

b. both Phaeodactylum and Thalassiosira are pennate diatoms with a cylindrical cell profile and sometimes forms short chains

c. Phaeodactylum is an example of centric diatoms with a cylindrical cell, whilst Thalassiosira is an example of a pennate diatom, having an elongated cell that sometimes forms short chains

d. Phaeodactylum is an example of a pennate diatom, with an elongated cell, whilst Thalassiosira is an example of a centric diatom, having a cylindrical cell that sometimes forms short chains

e. Phaedoactylum is an example of a centric diatom with a cylindrical cell, whilst Thalassiosira is an example of a pennate diatom, havong an elongated cell that never forms short chains.

Phaeodactylum is an example of a pennate diatom, with an elongated cell, whilst Thalassiosira is an example of a centric diatom, having a cylindrical cell that sometimes forms short chains.

plastid genomes: which best describes plastic genomes across different groups of aquatic protists like phytoplankton?

a. Plastid genomes are usually small in size, single molecules with circular topology, but there are exceptions. They contain protein-coding genes, rRNAs and tRNAs and use polycistronic transcription

b. plastid genomes are usually small in size, multiple molecules with circular topology, but there are exceptions. They contain protein-coding genes, rRNAs and tRNAs and use polycistronic transcription

c. plastid genomes are usually small in size, single molecules with linear topology, but there are exceptions. They contain protein-coding genes and rRNAs and use ploycistronic transcription

d. Plastid genomes are usually small in size, single molecules with circular topology, but there are exceptions. They contain protein-coding genes, rRNAs and tRNAs and use monocistronic transcription

e. plastid genomes are usually small in size, single molecules with linear topology, there are exceptions. They contain protein-coding genes, rRNAs and tRNAs and use monocistronic transcription

plastid genomes are usually small in size, single molecules with circular topology, but there are exceptions. They contain protein-coding genes, rRNAs and tRNAs and use polycistronic transcription

scattering: which is the best description of two types of scattering in conventional flow cytometry?

a. both side scattering (SSC) of light and forward scattering (FSC) relate to cell size

b. side scattering (SSC) of light relates to the structural complexity of cells, whilst forward scattering (FSC) relates to cell size

c. side scattering (SSC) of light relates to cell size, whilst forward scattering (FSC) relates to cell structural complexity and morphology

d. both side scattering (SSC) of light and forward scattering (FSC) relate to the structural complexity of cells

side scattering (SSC) of light relates to the structural complexity of cells, whilst forward scattering (FSC) relates to cell size.

plastid signalling: protist plastid are largely controlled by the nucleus. Which best describes plastid control and signalling?

a. proteins are targeted at the plastid by terminal/transit peptide, with feedback control by retrowave signalling

b. proteins are targeted at the plastid by terminal/transit peptides, with feedback control by retrograde signalling

c. proteins are targeted at the plastid by initiation/export peptides, with feedback control by retrograde signalling

d. proteins are targeted at the plastid by initiation/export peptides, with feedback control by retrowave signalling

proteins are targeted at the plastid by terminal/transit peptides, with feedback control by retrograde signalling

nucleomorph: what is a nucleomorph?

a. an “extra genome” found in dinoflagellates consisting of a few chromosomes that is a relic of an earlier endosymbiotic event

b. a compartment of the dinoflagellate nucleus (dikaryon) associated with cell cycle regulation

c. an “extra genome” found in haptophytes consisting of a few chromosomes that is a relic of an earlier endosymbiotic event

d. a compartment of the haptophyte nucleus associated with cell cycle regulation

e. an “extra genome” found in Cryptomonads consisting of a few chromosomes that is a relic of an earlier endosymbiotic event

an “extra genome” found in Cryptomonads consisting of a few chromosomes that is a relic of an earlier endosymbiotic event

culture independent methods: analyzing environmental samples of mixed bacterial communities often requires culture independent methods. Which is the best description?

a. both targeted amplicon sequencing of the 16S rRNA regions and whole metagenome sequencing can be used to identify microbes in environmental community samples

b. both targeted amplicon sequencing of the 16S rRNA regions and whole metagenome sequencing can be used to identify and enumerate microbes in environmental community samples

c. both targeted amplicon sequencing of the 18S rRNA regions and whole metagenome and sequencing can be used to identify microbes in environmental community samples

d. both targeted amplicon sequencing of the 18S rRNA regions and whole metagenome sequencing can be used to identify and enumerate microbes in environmental community samples

both targeted amplicon sequencing of the 16S rRNA regions and whole metagenome sequencing can be used to identify microbes in environmental community samples

ANAMMOX: what is ANAMMOX and why is it significant in the marine nitrogen cycle?

a. ANAMMOX refers to the anaerobic oxidation of ammonium, it converts ammonium to nitrate

b. ANAMMOX refers to the anaerobic oxidation of ammonium, it converts ammonium to nitrite

c. ANAMMOX refers to the anaerobic oxidation of ammonium, it converts ammonium to N2

d. ANAMMOX refers to the anaerobic oxidation of ammonium, it converts ammonium to nitrous oxide

ANAMMOX refers to the anaerobic oxidation of ammonium, it converts ammonium to N2

r vs K: microbes grow at different rates, with a general distinction between r and K type growth strategies. Which of the following sounds most accurate?

a. K-strategies generally have higher maximum growth rates than r-strategists under optimal conditions, whilst r-strategists are more competitive (have higher growth rates) under nutrient-limiting conditions

b. r-strategists generally have lower maximum growth rates than K-strategists under optimal conditions and under nutrient limiting conditions

c. r-strategists generally have higher maximum growth rates than K-strategist under optimal conditions and under nutrient-limiting conditions

d. r-strategists generally have higher maximum growth rates than K-strategists under optimal conditions, whilst K-strategists are more competitive (have higher growth rates) under nutrient limiting conditions

r-strategists generally have higher maximum growth rates than K-strategists under optimal conditions, whilst k-strategists are more competitive (have higher growth rates) under nutrient limiting conditions

diazotroph: what do diazotrophs do in the marine cycle?

a. diazotrophs fix ammonium, the oxidation of ammonia to nitrite. They are often found in polar seas, especially the southern and arctic oceans

b. diazotrophs fix ammonium, the oxidation of ammonia to nitrite. They are often found in tropical, low nitrogen/nutrient areas of the open ocean

c. diazotrophs fix dinitrogen, the reduction of N2 to ammonia. They are often found in polar seas, especially the southern and arctic oceans

d. diazotrophs fix ammonium, the reduction of ammonia to nitrite. They are often found in tropical, low nitrogen/nutrient areas of the open ocean

e. diazotrophs fix dinitrogen of N2 to ammonia. They are often found in tropical low nitrogen/nutrient areas of the open ocean

diazotrophs fix dinitrogen of N2 to ammonia. They are often found in tropical low nitrogen/nutrient areas of the open ocean

Monod: what is the Monod equation (Monod kinetics)?

a. an empirical interpretation of the Michaelis-menten equation that relates growth rate of a microorganism with the substrate concentration

b. an empirical interpretation of the Michaelis-menten kinetic that relates the growth rate of a microorganism with the temperature

c. an empirical interpretation of Michaelis-menten kinetics that relates the growth rate of a microorganism with enzyme kinetics

d. a conceptual interpretation of Michaelis-menten kinetics that relates the growth of a microorganism with the substrate concentration

e. a conceptual interpretation of Michaelis-menten kinetics that relates growth rate of a microorganism with the temperature

an empirical interpretation of the Michaelis-menten equation that relates growth rate of a microorganism with the substrate concentration

plastid endosymbiosis: plastids are diverse and colourful. Which if the following best describes the evolution of haptophytes, cryptophytes and heterokonts (including diatoms)?

a. evolved via a tertiary endosymbiotic event with plastids from a brown alga

b. evolved via a secondary endosymbiotic event with plastids derived from a brown alga

c. evolved via a tertiary endosymbiotic event with plastids from a red alga

d. evolved via a tertiary endosymbiotic event with plastids from a green alga

e. evolved via a secondary endosymbiotic event with plastids derived from a red alga

evolved via a secondary endosymbiotic event with plastids derived from a red alga

BGE: which best describes bacterial growth efficiency (BGE)?

a. BGE describes the total mass of aquatic organic matter that is used for cell maintenance, versus the proportion that is respired to CO2

b. BGE describes the proportion or efficiency of aquatic organic matter that is used for growth and bacterial cell production, versus the proportion that is respired to O2

c. BGE describes the proportion or efficiency of aquatic organic matter that is used for growth and bacterial cell production, versus the proportion that is respired to CO2

d. BGE describes the total mass of aquatic organic matter that is used for growth and bacterial cell production, versus the proportion that is respired to CO2

e. BGE describes the total mass of aquatic organic matter that is used for growth and bacterial cell production, versus the proportion that is respired to O2

BGE describes the proportion or efficiency of aquatic organic matter that is used for growth and bacterial cell production, versus the proportion that is respired to CO2

PCR: PCR amplification can be done starting with RNA as well as DNA. To perform PCR starting with RNA, which extra step is needed?

a. RNA is treated with an extra enzyme, DNA polymerase, to make single stranded DNA, before PCR

b. RNA is treated with an extra enzyme, DNA polymerase, to make complementary DNA or cDNA, before PCR

c. RNA is treated with an extra enzyme, reverse transcriptase, to make single-stranded DNA, before PCR

d. RNA is treated with an extra enzyme, reverse transcriptase, to make complementary DNA or cDNA, after PCR

e. RNA is treated with an extra enzyme, reverse transcriptase, to make complementary DNA or cDNA, before PCR

RNA is treated with an extra enzyme, reverse transcriptase, to make complementary DNA or cDNA, before PCR

HNLC: some areas of the ocean are known as HNLC regions, or “high nutrient, low chlorophyll” regions. Which best describes these areas?

a. HNLC regions are characterized by low phytoplankton abundance, largely because they are depleted in trace metals such as iron. An example is the Baltic Sea

b. HNLC regions are characterized by low phytoplankton abundance, largely because they are depleted in nitrate and phosphate. An example is the Baltic Sea

c. HNLC regions are characterized by low phytoplankton abundance, largely because they are depleted in trace metals such as iron. An example is the Southern Ocean

d. HNLC regions are characterized by high phytoplankton abundance, largely because they are depleted in nitrate and phosphate. An example is the Southern ocean.

HNLC regions are characterized by low phytoplankton abundance, largely because they are depleted in trace metals such as iron. An example is the Southern Ocean

how big is a typical bacterium in seawater samples? (multiple answers can be chosen)

a. 0.05 to 0.1 microns

b. 0.5 to 1 micron

c. 1 to 5 microns

d. 10 to 50 microns

e. 0.1 to 1 mm

0.5 to 1 micron and 1 to 5 microns

nitrification: the nitrogen cycle is strange and wonderful. Which describes nitrification?

a. Nitrification is oxidation of nitrogen compounds. Two main steps converting Nitrate to Nitrite, and Nitrite to Ammonium

b.Nitrification is oxidation of nitrogen compounds. Two main steps converting Ammonia to Nitrite, and Nitrite to Nitrate

c. Nitrification is reduction of nitrogen compounds. Two main steps converting Ammonia to Nitrite, and Nitrite to Nitrate

d. Nitrification is reduction of nitrogen compounds. Two main steps converting Nitrate to Nitrite, and Nitrite to Ammonium.

Nitrification is oxidation of nitrogen compounds. Two main steps converting Ammonia to Nitrite, and Nitrite to Nitrate

redfield: what does the redfield ratio refer to?

a. the ratio of carbon, nitrogen and iron in ocean microbes, that averages about 106:10:1 respectively

b. the ratio of carbon, nitrogen, and iron in ocean microbes, that averages about 106:16:1 respectively

c. The ratio of carbon, nitrogen and silica in ocean microbes, that averages about 106:12:1 respectively

d. the ratio of carbon, nitrogen and phosphorous in ocean microbes, that averages about 106:16:1 respectively

e. the ratio of carbon, nitrogen and phosphorous in ocean microbes, that beverages about 106:12:1 respectively

the ratio of carbon, nitrogen and phosphorous in ocean microbes, that averages about 106:16:1 respectively

CH4 pathways: two main pathways for methane production by wetland and aquatic microbes are (multiple answers can be chosen):

a. Acetotrophic and hydrogenoclastic methanogenesis

b. Acetoclastic and hydrogenoclastic methanogenesis

c. Acetotrophic and hydrogenotrophic methanogenesis

d. acetoclastic and hydrogenotrophic methanogenesis

Acetoclastic and hydrogenoclastic methanogenesis; acetoclastic and hydrogenotrophic methanogenesis

life: which best describes the current tree of life?

a. a 3 domain model, with archaea derived from prokaryotic and eukaryotic ancestors

b. a 3 domain model, with eukaryotes derived from prokaryotic and archaeal ancestors

c. a 3 domain model, with archaea derived from prokaryotic ancestors

d. a 2 domain model, with eukaryotes derived from prokaryotic and archaeal ancestors

e. a 2 domain model, with archaea derived from prokaryotic and eukaryotic ancestors

a 2 domain model, with eukaryotes derived from prokaryotic and archaeal ancestors

phosphorous: which of the following accounts for about half of cellular phosphorous, at least in photosynthetic organisms?

a. DNA

b. storage polyphosphate

c. phospholipids

d. ATP

e. RNA/ribosomes

RNA/ribosomes

size growth rate: which best describes the relation between cell size and growth rate?

a. cell size and growth rate are sometimes positively correlated across different microbe species

b. cell size and growth rate are not correlated across different microbe species

c. cell size and growth rate are sometimes negatively correlated across different microbe species

d. cell size and growth rate are strongly correlated across different microbe species

cell size and growth rate are strongly correlated across different microbe species