D
Punctuated equilibrium is a series of small, gradual changes over long periods of time.
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.
Answer:
It's going to be:
A-Endospores can survive extreme heat, lack of water, radiation, and exposure to many toxic chemicals.
C-Endospores are highly durable dehydrated cells with thick cell walls.
ANSWER IS A and C
Answer:
See the answer below
Explanation:
Homeostasis refers to the maintenance of relatively constant internal body processes. This is done in two ways
- <em>Negative feedbacks</em>
- <em>Positive feedbacks</em>
Negative feedback returns body processes back to normal after the process has been breached. An example is when the body temperature becomes too high or too low. At too high temperature, vasodilation of the skin's blood vessels occurs and more heat is lost to the surrounding from the skin, sweat is also produced by sweat glands and evaporation of the seat causes cooling. At too low temperature, vasoconstriction occurs leading to the conservation of more heat. The muscles also shake to generate more body heat
Positive feedback ensures that a breach of body processes reaches completion. An example is when a pregnant woman starts laboring. The increase in the amount of oxytocin in the blood leads to the contraction of the uterus consequently leading to the opening of the cervix. More and more oxytocin leads to more frequent and stronger contraction of the uterus untill the baby is born.
