PCA FINAL EXAM Questions With 100% Correct
Verified Answers Latest Updated 2026/2027
(GRUARANTEED PASS)
What are the three components of plant disease triangle - VERIFIED
ANSWER - the environment, the host, and the causal agent
What is the role of each of the component of the disease triangle -
VERIFIED ANSWER - All three must be present in order for infection to take
place, the environment must favor the causal agent and the host must be
susceptible to the causal agent
What is feature selection in dimensionality reduction? - VERIFIED ANSWER
- Keeping only the features that contribute the most to the prediction
variable or output you're interested in. Remove redundancies
What is latent feature extraction? - VERIFIED ANSWER - Creating new
combinations of attributes that capture the essential information in the
data with fewer dimensions.
,What is principal component analysis? - VERIFIED ANSWER - PCA is a
multivariate statistical technique to reduce higher dimensional data to
lower dimensions, remove noise, and extract crucial information such as
features and attributes from large amounts of data.
What are the general objectives of principal component analysis? -
VERIFIED ANSWER - Data reduction and interpretation.
What does principal component analysis transform correlated variables
into? - VERIFIED ANSWER - A smaller set of uncorrelated variables called
principal components.
What is a common use of principal component analysis? - VERIFIED
ANSWER - It is often used as the first step in factor analysis.
What does PCA transform correlated variables into - VERIFIED ANSWER -
Transforms them into uncorrelated variables
,What does calculating the Covaraince Matrix do? - VERIFIED ANSWER -
Matrix reveals how each variable in the dataset relates to every other
variable , revealing correlations and variance structures
How do humans impact the disease triangle - VERIFIED ANSWER - Humans
can manipulate the environment, plant host resistant varieties, and use
preventative/suppressive/eradicative pesticides all to change a piece of
the disease triangle
How does one component of the triangle impact a epidemic if it does not
come into contact with the other two - VERIFIED ANSWER - If one
component of the plant disease triangle is missing the epidemic will slow
to a halt, in order for the disease to spread it must have all three parts of
the triangle
How can you break the environment portion of the disease triangle -
VERIFIED ANSWER - alter planting dates, remove alternative host, alter
harvest dates
How can you break the host portion of the disease triangle - VERIFIED
ANSWER - alternate crop, plant host resistance species
, How can you break the causal agent portion of the disease triangle -
VERIFIED ANSWER - Pesticide application
How does the disease triangle help in diagnosis - VERIFIED ANSWER - If
you understand the plant disease triangle you can use the host species
and environment of a area where the crop is planted to rule out different
pathogens
How can host eradication be utilized for control of pathogens - VERIFIED
ANSWER - Host eradication is the eradication of a host plant that can
serve as a primary source of inoculum (Quarantines failed for plum pox
virus, 20 trees in radius of infected tree were eradicated)
How can irrigation management effect foliar diseases - VERIFIED ANSWER
- Excess moisture is a key factor for bacterial infection these can be
reduced by using fans, increase plant spacing, dew removal, reduce
shade, time irrigation
How can irrigation and soil drainage affect pythium damping off - VERIFIED
ANSWER - found in irrigation water, so sanitation is important to reduce
infection
Verified Answers Latest Updated 2026/2027
(GRUARANTEED PASS)
What are the three components of plant disease triangle - VERIFIED
ANSWER - the environment, the host, and the causal agent
What is the role of each of the component of the disease triangle -
VERIFIED ANSWER - All three must be present in order for infection to take
place, the environment must favor the causal agent and the host must be
susceptible to the causal agent
What is feature selection in dimensionality reduction? - VERIFIED ANSWER
- Keeping only the features that contribute the most to the prediction
variable or output you're interested in. Remove redundancies
What is latent feature extraction? - VERIFIED ANSWER - Creating new
combinations of attributes that capture the essential information in the
data with fewer dimensions.
,What is principal component analysis? - VERIFIED ANSWER - PCA is a
multivariate statistical technique to reduce higher dimensional data to
lower dimensions, remove noise, and extract crucial information such as
features and attributes from large amounts of data.
What are the general objectives of principal component analysis? -
VERIFIED ANSWER - Data reduction and interpretation.
What does principal component analysis transform correlated variables
into? - VERIFIED ANSWER - A smaller set of uncorrelated variables called
principal components.
What is a common use of principal component analysis? - VERIFIED
ANSWER - It is often used as the first step in factor analysis.
What does PCA transform correlated variables into - VERIFIED ANSWER -
Transforms them into uncorrelated variables
,What does calculating the Covaraince Matrix do? - VERIFIED ANSWER -
Matrix reveals how each variable in the dataset relates to every other
variable , revealing correlations and variance structures
How do humans impact the disease triangle - VERIFIED ANSWER - Humans
can manipulate the environment, plant host resistant varieties, and use
preventative/suppressive/eradicative pesticides all to change a piece of
the disease triangle
How does one component of the triangle impact a epidemic if it does not
come into contact with the other two - VERIFIED ANSWER - If one
component of the plant disease triangle is missing the epidemic will slow
to a halt, in order for the disease to spread it must have all three parts of
the triangle
How can you break the environment portion of the disease triangle -
VERIFIED ANSWER - alter planting dates, remove alternative host, alter
harvest dates
How can you break the host portion of the disease triangle - VERIFIED
ANSWER - alternate crop, plant host resistance species
, How can you break the causal agent portion of the disease triangle -
VERIFIED ANSWER - Pesticide application
How does the disease triangle help in diagnosis - VERIFIED ANSWER - If
you understand the plant disease triangle you can use the host species
and environment of a area where the crop is planted to rule out different
pathogens
How can host eradication be utilized for control of pathogens - VERIFIED
ANSWER - Host eradication is the eradication of a host plant that can
serve as a primary source of inoculum (Quarantines failed for plum pox
virus, 20 trees in radius of infected tree were eradicated)
How can irrigation management effect foliar diseases - VERIFIED ANSWER
- Excess moisture is a key factor for bacterial infection these can be
reduced by using fans, increase plant spacing, dew removal, reduce
shade, time irrigation
How can irrigation and soil drainage affect pythium damping off - VERIFIED
ANSWER - found in irrigation water, so sanitation is important to reduce
infection
