Which was the first human therapeutic protein to be expressed in genetically modified plants?

• A) Interferon
• B) Human serum albumin
• C) Insulin
• D) Growth hormone

Why is transfection with polyplexes considered more efficient than some other chemical methods?

• A) Because they do not require any cells
• B) Because they work only in plant cells
• C) Because they have a uniform particle size
• D) Because they are cheaper to produce

Which trait is the most widespread in commercial transgenic plants?

• A) Drought tolerance
• B) Herbicide resistance
• C) Insect resistance
• D) Salt tolerance

Protoplast transformation is highly efficient for DNA uptake but can be limiting for generating whole transgenic plants. What is a major downstream challenge after successfully transforming a protoplast?

• A) It is difficult to regenerate an entire fertile plant from a single protoplast.
• B) The protoplasts are immediately resistant to antibiotics.
• C) Protoplasts cannot express foreign genes.
• D) The transformation is only transient.

A biotechnology company needs a homogeneous population of single plant cells for high-throughput screening of a new herbicide. They start with a solid callus culture. What should be their next critical step to achieve this?

• A) Induce somatic embryogenesis in the callus.
• B) Subject the callus to cryopreservation.
• C) Treat the callus with a cell wall-digesting enzyme.
• D) Transfer the callus to a liquid medium and agitate it on a shaker.

What confers the ability to induce tumors in Agrobacterium tumefaciens?

• A) Ti-plasmid
• B) Chromosomal DNA
• C) Mitochondrial DNA
• D) Ribosomal RNA

T-DNA genes in Agrobacterium tumefaciens are involved in:

• A) Photosynthesis
• B) Nitrogen fixation
• C) Synthesis of phytohormones and opines
• D) Cell wall degradation

What is the approximate velocity required for metal particles to penetrate plant cell walls in particle bombardment?

• A) 50 m/s
• B) 500 m/s
• C) 100 m/s
• D) 250 m/s

In an experiment, a researcher creates a nutrient medium containing only a high concentration of auxins to initiate callus from leaf explants. The callus forms but quickly begins to differentiate into roots. What is the most likely explanation?

• A) The explant was contaminated.
• B) The sugar concentration was too low.
• C) The balance of hormones was incorrect; cytokinins were needed to suppress differentiation.
• D) The temperature was too high.

When was the expression of foreign genes in plants first successfully achieved?

• A) Mid-1990s
• B) Early 2000s
• C) Early 1980s
• D) Late 1970s

What is essential in the nutrient medium to maintain plant cells in an undifferentiated state for callus formation?

• A) Correct balance of auxins, cytokinins, and gibberellins
• B) High sugar concentration
• C) Only auxins
• D) Only cytokinins

How is a cell suspension culture obtained?

• A) By transferring callus into liquid medium with agitation
• B) By grinding plant leaves
• C) By freezing plant cells
• D) By exposing cells to UV light

A company wants to produce a very high yield of a recombinant vaccine protein in tobacco leaves. They are deciding between nuclear and chloroplast transformation. Which factor, specific to chloroplast transformation, provides the strongest argument for its use in this scenario?

• A) Chloroplast genes are not subject to gene silencing.
• B) Chloroplast transformation avoids the use of antibiotic resistance marker genes.
• C) Chloroplasts are larger and easier to isolate.
• D) The high copy number of chloroplasts per cell can lead to vastly higher protein accumulation.

A researcher in 1995 wanted to transform a novel ornamental plant species that had never been genetically modified before. Based on the historical development of plant transformation, what was the most significant challenge they likely faced?

• A) Obtaining permission for field trials
• B) Isolating the plant's DNA
• C) Developing a routine transformation protocol for that specific species
• D) Sequencing the plant's genome

Why is chloroplast transformation preferred for high-level transgene expression?

• A) Chloroplast DNA is more stable than nuclear DNA
• B) Thousands of chloroplasts per cell allow higher expression
• C) Chloroplasts are not affected by RNA interference
• D) Chloroplasts are easier to isolate

When using Agrobacterium tumefaciens for plant transformation, the Ti-plasmid is modified to be "disarmed." What is the primary purpose of this disarming?

• A) To make the plasmid easier to insert into the bacterium.
• B) To increase the copy number of the plasmid in Agrobacterium
• C) To prevent the transfer of tumor-forming genes to the plant genome.
• D) To allow the plasmid to replicate in plant cells.

In its natural state, Agrobacterium transfers T-DNA that includes genes for phytohormone synthesis. What is the evolutionary advantage for the bacterium in having the plant produce these hormones?

• A) To increase the plant's photosynthetic rate.
• B) To create a nutrient-rich environment (opines) for the bacterium to consume.
• C) To strengthen the plant cell walls.
• D) To make the plant resistant to insects.

A scientist is reviewing gene transfer methods. They note that "Chemical and physical direct DNA transfer" is a distinct category from "Bacterial gene delivery." What fundamental conceptual difference best separates these categories?

• A) The cost and time involved.
• B) The ploidy level of the recipient plant cells.
• C) The type of gene being transferred.
• D) Whether a biological vector is used.

Compared to Agrobacterium-mediated transformation, particle bombardment is often preferred for transforming cereal crops like wheat and rice. What is the most relevant analytical reason for this preference?

• A) Particle bombardment is a much older and more trusted technology.
• B) Agrobacterium does not naturally infect monocots like cereals as efficiently as dicots.
• C) Particle bombardment never causes genomic rearrangements.
• D) Particle bombardment is always cheaper and faster.

Under normal conditions, transcription terminates:

• A) At the ends of genes
• B) At the beginning of the gene
• C) In the middle of the gene
• D) Only when DNA is damaged