4.6 billion years ago
The study pushes back the clock on the origin of Earth's water by hundreds of millions of years, to around 4.6 billion years ago, when all the worlds of the inner solar system were still forming. Scientists had suspected that our planet formed dry, with high-energy impacts creating a molten surface on the infant Earth.
i hope this helped, have a nice day! (o:
Answer:
A
Explanation:
The two genes are B and b are located in the same spot, therefore they are alleles or alternative forms of the same gene.
Answer:
Recombinant DNA
Explanation:
Recombinant DNA can be used to change the genetic makeup of a cell, as in adding a gene to make a bacterial cell produce insulin.
Answer:
Nervous stimulus action for muscle contraction
Explanation:
Nerve stimulation is sent to the sarcolemma, which are motor nerves at the neuromuscular junction (junction between the terminal part of a motor axon with a motor plate), after which nerve endings implant in the sarcolemma and form plaque on the surface of muscle fibers, which in turn transmit stimulus to the musculature.
Then, an electrical current (from the stimuli) is generated, it propagates through the muscle cell membrane, reaches the cytoplasm and triggers the muscle contraction mechanism.
