Answer:
A. Glucose:
As lactose is absent will follow the glucose metabolism, so the lac repressor will hold tightly with the operator which leads to the prevention of transcription as RNA polymerase can not bind to promoter so no lactose metabolism.
B. lactose:
In the case or wild mutant lactose metabolism will occur as lactose is present, allolactose binds to the lac repressor thus the operator and promoter are free so transcription starts. The same result will be in all test except in the case of a mutant repressor.
C. glucose and lactose:
In this case, diauxic growth will occur. This growth takes place when two sugars are present in the media. The preferred sugar will be consumed first That is glucose. Then a lag phase will come which will be followed by the second sugar metabolism that is lactose. the given two cases :
Lactose will be metabolized first, as operator site mutation prevents repressor protein binding and thus will lead to the constitutive synthesis of lac operon in test B.
The same thing will happen, as in this case also, constitutive synthesis of lac operon will happen in test C.
Cultures grown in the presence of both glucose and lactose are metabolizing lactose. In the test (b) and (c) will be responsible due to constitutive synthesis of lac operon will happen.
The spines of the cactus have several functions, which are the following:
To defend them from possible predators: inside the body of the plants there is a great deal of water; if herbivores could access it, these plants would not survive.
To provide them with shade: it is true that not much, but it is enough so that the loss of water by evaporation is minimal.
Reflect sunlight: many species have white spines.
Answer:
C. tarsal glands: produce tears
Explanation:
The tarsal plate refers to a thick fold of connective tissue that serves as a support to the eyelids. A row of tarsal glands is embedded in each tarsal plate. Tarsal glands are elongated modified sebaceous glands. Also known as meibomian glands, they secrete a fluid that helps keep the eyelids from adhering to each other. These glands do not produce tears. Tears are produced by lacrimal glands present in the lacrimal apparatus.
The answer is False. New stars are created all the time
