Response:
B. The meanings of the prefixes chemo- and photo- point to the source of electrons.
Explanation:
The term chemo refers to chemical/drug, whereas photo relates to light. This can be demonstrated through the following examples:
Chemotherapy = treatment using chemicals
Phototherapy = treatment utilizing light
Answer:
Option (A).
Explanation:
The lac operon system in bacteria elucidates the process of lactose metabolism within the cell. The initial operon system was identified by Jacob and Monod. An operon is characterized as a cluster of genes transcribed together as a single RNA unit.
When both glucose and lactose are available in the media, the bacterium favors metabolizing glucose. The presence of glucose is recognized by the bacterial cell as the CAP-cAMP complex is essential for transcription, and its levels are reduced in glucose's presence. This mechanism effectively halts the transcription of lactose genes even when lactose is available.
Consequently, the right answer is option (A).
Biomes located in temperate zones have undergone the most significant alterations due to human actions. Biomes can be described as communities or assemblages of organisms that are grouped based on shared environmental characteristics. There are five major categories of biomes: aquatic, desert, forest, grassland, and tundra.
Response: Option D.
Justification:
Active transport refers to how molecules or solutes travel through a membrane based on solute concentration differences.
This process is constant due to diffusion, which ensures ongoing movement of solutes across the membrane. Cells have reduced sodium (Na+) levels but increased potassium (K+) levels. Therefore, sodium's electrical and concentration gradients promote the ion's entry into the cell, assisted by the positive charge of Na+, which encourages inward movement to the negatively charged interior.
Thus, the right choice is D.
Population density = total number of individuals divided by land area
land area should be expressed in square kilometers
thus, 120 ha = 120 x 0.01 = 1.2 square kilometers since 1 ha = 0.01 square kilometers
total population= (80 x 1500)/100 = 1200
so, the population density is 1200/1.2 = 1000
