When bacteria are inoculated into a new sterile nutrient broth, their numbers don't begin to increase immediately. instead, there is a lag phase that may last for an hour or even several days. why don't bacterial numbers increase immediately?
a. the bacteria have to establish a biofilm before their numbers can increase.
b. there are not enough nutrients for the bacteria to grow, and growth is delayed until there are some dead cells to cannibalize.
c. the medium contains inhibitors that prohibit rapid growth of the bacteria, and these must be inactivated before bacterial numbers will increase.
d. the bacteria must adjust to the nutrient content in the new medium, synthesizing necessary amino acids, growth factors, and enzymes.

The correct answer is D. The bacteria must adjust to the nutrient content in the new medium, synthesizing necessary amino acids, growth factors, and enzymes.

Explanation:

As a bacteria enters a new medium it is not able to divide immediately because the environment of a new medium is different from the old medium. A new medium may contain a different and complex food source for which bacteria have to synthesize new enzymes and growth factors.

So initially bacteria remain in the log phase which shows that the bacteria is adjusting in its new medium and synthesizing necessary amino acids, growth factors, and enzymes required for their growth in the new medium.

Therefore the correct answer is D.

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !

the oldest known insects are believed to live around 400 millions ago as suggested by the fossil records.   some plants having woody stems also evolved during this time.

after the evolution of insects the first four legged species or the tetrapods evolved in shallow freshwater habitats from the intermediate species approximately 397 million years ago. the tetrapods went on conquering the land giving rise to amphibians, reptiles, mammals and birds.

the major split in tetrapods first occurred 340 million years ago branching off from amphibians.

363 million years ago when the carboniferous period began the insects started roaming on land and taking flights, following which the four limbed tetrapods adapted in the terrestrial habitat.