Oparin and Haldane's theory and Miller's experiment are the proof that long complex molecules that carry information such as DNA, might have formed on early earth.
Explanation:
Oparin and Haldane Hypothesis states that life on Early earth could have evolved by chemical evolution.
Oparin and Haldane said that the reducing atmosphere of the early earth caused simple inorganic molecules to react by using sunlight and formed molecules like amino acids and nucleotides.
These monomers combined to form polymers, they would have attained self-replicating tendency eventually these would have assembled into structures and these macromolecules had also made membrane-bound organelle.
Although this hypothesis is not fully accepted but part of it which talks about formation of molecules is accepted.
Millers and Urey in their experiment created an artificial reducing environment like that of early earth. They used a heated pool of water, atmospheric gases like H2O,CH4,N2, NH4 and sparks of electricity. After running the experiment for some days they found that amino acids, sugars, lipids and other organic molecules had formed.
Their hypothesis is not fully accepted but part of is evident that organic building block is formed from inorganic constituent on the earth.
Answer:
both options 4 and 3 is the answer..
Answer:
The given statement is false.
A neuron is the basic structural and functional unit of the nervous system. It helps in transmitting information from one neuron to another neuron, gland, or muscle cell.
The conduction of nerve impulse is electrochemical in nature. It transmits the impulse electrically through the axon the nerve cells and chemically through synapses (gap between two nerves cells).
The axon terminals of pre-synaptic nerve cell release chemical messengers (also called neurotransmitters) in the synaptic cleft. These messengers then bind to the receptors present on the post-synaptic nerve cell and regenerate the nerve impulse.
B.Incorrect. When transcription is transcribed from the gene for transcription, only a string of DNA is used as a template by the RNA polymerase.
Pre-embryonic cleavages make use of the abundant cytoplasm of the conceptus as the cells rapidly divide without changing the total volume.
