The technique of polymerase chain reaction (PCR) is used to:
A. Cut DNA at specific sites
B. Sequence DNA
C. Amplify a specific DNA sequence
D. Separate DNA fragments by size
Answer: Option C
Solution (By JKSSB Mock Tests)
PCR is an in vitro technique to exponentially amplify a specific DNA segment using primers, Taq polymerase, and thermal cycles. Electrophoresis separates DNA, sequencing determines base order, restriction enzymes cut DNA.
Explanation:
Transpiration from stomata creates negative water potential in leaves, generating a tension (transpiration pull) that draws water upward through the xylem from roots. This cohesion-tension mechanism is the primary driver of water transport in tall trees. Root pressure and capillary action are minor forces.
Explanation:
Plasmolysis occurs when a plant cell is placed in a hypertonic solution, causing water to leave the cell by exosmosis, leading to shrinkage of the protoplasm and its detachment from the cell wall. Incipient plasmolysis is when protoplast just starts to pull away. Opposite is deplasmolysis (when placed in hypotonic solution). Swelling is turgidity. Animal cells undergo crenation or lysis.
Consider statements about the Golgi apparatus: 1. It has cis and trans faces. 2. It modifies and packages proteins. 3. It synthesizes ATP. Which are correct?
Explanation:
The Golgi apparatus consists of flattened membranous sacs called cisternae. It has a forming cis face near the ER and a maturing trans face directed towards the plasma membrane. It primarily modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles. It does not synthesize ATP; that is the function of mitochondria.
No comments yet. Be the first to start the discussion!