Question 1

Where are abscisic acid receptors located in plant cells?

Accepted Answer

Abscisic acid receptors in plant cells are located in the plasma membrane.

Question 2

Which type of plant hormone is generally responsible for long-term inhibition of plant growth such as in buds and seeds?

Accepted Answer

Abscisic acid is generally responsible for long-term inhibition of plant growth such as in buds and seeds.

Question 3

Which of the following types of plant hormones is apparently synthesized from carotenoid pigments inside plastids?

Accepted Answer

Abscisic acid is apparently synthesized from carotenoid pigments inside plastids.

Question 4

After a plant has survived a microbial invasion, the rest of the plant is often less vulnerable to future infections. What is this called?

Accepted Answer

This is known as systemic acquired resistance, where the plant activates a broad-spectrum defense response that provides protection against a range of pathogens. This response is induced by the initial infection and can provide long-lasting, systemic protection to the rest of the plant.

Question 5

What are chitinases examples of?

Accepted Answer

Chitinases are examples of PR (pathogenesis-related) proteins, which are induced in plants in response to pathogen attack or other stresses.

Question 6

In systemic acquired resistance, the regulatory protein NPR-1 moves from the cytoplasm to the cell nucleus. What is this a consequence of?

Accepted Answer

The movement of the regulatory protein NPR-1 from the cytoplasm to the nucleus in systemic acquired resistance is a consequence of a buildup of salicylic acid in the cytoplasm. Salicylic acid is a key signaling molecule in SAR and activates various defense-related genes, including NPR-1. Upon activation, NPR-1 translocates to the nucleus where it interacts with other transcription factors to regulate gene expression and activate the plant's defense response.

Question 7

When a plant has a hypersensitive response, which production triggers effects such as the expression of PR proteins?

Accepted Answer

Salicylic acid is a hormone that is produced in response to pathogen infection or other stressors, and it triggers the expression of pathogenesis-related (PR) proteins, which help to defend the plant against the pathogen.

Question 8

Imagine that you own a nursery and you want to reduce the chance that plants you ship will suffer from shipping damage. Which type of plant hormone should you apply to the plants before shipping?

Accepted Answer

Abscisic acid is a plant hormone that can help reduce water loss and promote dormancy, which can help prevent damage during shipping.

Question 9

Which of the following types of plant hormones trigger(s) plant responses to environmental stresses such as cold snaps, high salinity, and drought?

Accepted Answer

Abscisic acid triggers plant responses to environmental stresses such as cold snaps, high salinity, and drought. Cytokinins promote cell division and growth, oligosaccharins are involved in plant defense mechanisms, and jasmonates are involved in plant responses to biotic stresses such as herbivory and pathogen attack.

Question 10

What are statoliths (particles that move in the direction gravity pulls them) typically in plants?

Accepted Answer

Statoliths are specialized organelles that contain dense particles and are involved in gravity sensing in plants. The most common type of statoliths found in plants are amyloplasts, which are organelles that store starch. These dense particles are free to move within the cell and settle under the influence of gravity, allowing the plant to sense its orientation with respect to gravity. The other options, calcium carbonate crystals, nuclei, and vacuoles, are not commonly involved in gravity sensing in plants.

Question 11

Why are secondary metabolites termed "secondary"?

Accepted Answer

Secondary metabolites are not synthesized in all plant cells as part of basic metabolism, hence they are called secondary. Primary metabolites are synthesized as part of basic metabolism while secondary metabolites are produced in specific organs, tissues or under specific environmental conditions.

Question 12

Which synthesis is triggered when cells bind systemin?

Accepted Answer

Systemin is a peptide that is produced in response to herbivore damage and is involved in the activation of jasmonate synthesis. Therefore, when cells bind systemin, it triggers the synthesis of jasmonate. Gibberellin, auxin, and cytokinin are not directly involved in the systemin signaling pathway.

Question 13

Which of the following triggers stomatal closure by involving the second messenger inositol triphosphate (IP₃)?

Accepted Answer

Abscisic acid is the plant hormone that triggers stomatal closure by involving the second messenger inositol triphosphate (IP₃). Auxin, oligosaccharin, and salicylic acid do not have a direct role in stomatal closure by IP₃.

Question 14

What are secondary metabolites that function to protect plants from viral, fungal, and bacterial pathogens?

Accepted Answer

Phytoalexins are secondary metabolites that are produced by plants in response to microbial infection or other stress conditions, and function to protect the plant from viral, fungal, and bacterial pathogens.

Question 15

Which type of plant signalling molecule is similar in structure to aspirin?

Accepted Answer

Salicylic acid is the plant signalling molecule that is similar in structure to aspirin. In fact, aspirin is derived from salicylic acid. Both molecules contain a similar chemical structure known as a benzene ring and a carboxyl group. This similarity allows aspirin to function in a similar way to salicylic acid in plants, as both molecules can activate similar pathways and genes.

Question 16

Which type of plant hormone stimulates stomata to close during a drought?

Accepted Answer

Abscisic acid is the plant hormone responsible for stimulating stomata to close during a drought as a means of conserving water.

Question 17

Light of which wavelengths is the main stimulus for phototropism?

Accepted Answer

Blue light is the main stimulus for phototropism in plants. It is absorbed by the phototropins, which are photoreceptor proteins that trigger the movement of plant cells in response to light.

Question 18

Which plant signalling compounds are produced from structural elements of the cell wall?

Accepted Answer

Oligosaccharins are plant signalling compounds that are produced from structural elements of the cell wall. They are derived from the breakdown of certain polysaccharides in the cell wall, and can act as elicitors of plant defense responses. Salicylic acids and abscisic acids are not produced from the cell wall, although they may play important roles in plant signaling. Auxins are a class of plant hormones that are not produced from the cell wall, but are synthesized in the plant's meristem and transported to other parts of the plant.

Question 19

Which of the following are chaperone-type proteins that stabilize other proteins in response to environmental stresses such as salinity, drought, heat, and cold?

Accepted Answer

Heat-shock proteins are chaperone-type proteins that stabilize other proteins in response to environmental stresses such as salinity, drought, heat, and cold. Phytoalexins are antimicrobial compounds, PR proteins are pathogenesis-related proteins, and R genes are resistance genes involved in plant defense against pathogens.

Question 20

Which of the following was the first peptide hormone discovered in plants that functions in wound response in the tomato?

Accepted Answer

Systemin was the first peptide hormone discovered in plants that functions in wound response in the tomato. It was discovered in 1991 by Dr. Clarence A. Ryan and his team at Cornell University. Systemin is involved in the systemic wound response in tomato plants, triggering the production of protease inhibitors, which help to deter herbivores.

Quiz 38: Plant Signals and Responses to the Environment

Where are abscisic acid receptors located in plant cells?

Which type of plant hormone is generally responsible for long-term inhibition of plant growth such as in buds and seeds?

Which of the following types of plant hormones is apparently synthesized from carotenoid pigments inside plastids?

After a plant has survived a microbial invasion, the rest of the plant is often less vulnerable to future infections. What is this called?

What are chitinases examples of?

In systemic acquired resistance, the regulatory protein NPR-1 moves from the cytoplasm to the cell nucleus. What is this a consequence of?

When a plant has a hypersensitive response, which production triggers effects such as the expression of PR proteins?

Imagine that you own a nursery and you want to reduce the chance that plants you ship will suffer from shipping damage. Which type of plant hormone should you apply to the plants before shipping?

Which of the following types of plant hormones trigger(s) plant responses to environmental stresses such as cold snaps, high salinity, and drought?

What are statoliths (particles that move in the direction gravity pulls them) typically in plants?

Why are secondary metabolites termed "secondary"?

Which synthesis is triggered when cells bind systemin?

Which of the following triggers stomatal closure by involving the second messenger inositol triphosphate (IP₃) ?

What are secondary metabolites that function to protect plants from viral, fungal, and bacterial pathogens?

Which type of plant signalling molecule is similar in structure to aspirin?

Which type of plant hormone stimulates stomata to close during a drought?

Light of which wavelengths is the main stimulus for phototropism?

Which plant signalling compounds are produced from structural elements of the cell wall?

Which of the following are chaperone-type proteins that stabilize other proteins in response to environmental stresses such as salinity, drought, heat, and cold?

Which of the following was the first peptide hormone discovered in plants that functions in wound response in the tomato?

Quiz 38: Plant Signals and Responses to the Environment

Where are abscisic acid receptors located in plant cells?

Which type of plant hormone is generally responsible for long-term inhibition of plant growth such as in buds and seeds?

Which of the following types of plant hormones is apparently synthesized from carotenoid pigments inside plastids?

After a plant has survived a microbial invasion, the rest of the plant is often less vulnerable to future infections. What is this called?

What are chitinases examples of?

In systemic acquired resistance, the regulatory protein NPR-1 moves from the cytoplasm to the cell nucleus. What is this a consequence of?

When a plant has a hypersensitive response, which production triggers effects such as the expression of PR proteins?

Imagine that you own a nursery and you want to reduce the chance that plants you ship will suffer from shipping damage. Which type of plant hormone should you apply to the plants before shipping?

Which of the following types of plant hormones trigger(s) plant responses to environmental stresses such as cold snaps, high salinity, and drought?

What are statoliths (particles that move in the direction gravity pulls them) typically in plants?

Why are secondary metabolites termed "secondary"?

Which synthesis is triggered when cells bind systemin?

Which of the following triggers stomatal closure by involving the second messenger inositol triphosphate (IP3) ?

What are secondary metabolites that function to protect plants from viral, fungal, and bacterial pathogens?

Which type of plant signalling molecule is similar in structure to aspirin?

Which type of plant hormone stimulates stomata to close during a drought?

Light of which wavelengths is the main stimulus for phototropism?

Which plant signalling compounds are produced from structural elements of the cell wall?

Which of the following are chaperone-type proteins that stabilize other proteins in response to environmental stresses such as salinity, drought, heat, and cold?

Which of the following was the first peptide hormone discovered in plants that functions in wound response in the tomato?

Which of the following triggers stomatal closure by involving the second messenger inositol triphosphate (IP₃) ?