Answer:
C.
Explanation:
Nitrogen fixation is a process by which molecular nitrogen in the air is converted into ammonia or related nitrogenous compounds in soil. Atmospheric nitrogen is molecular dinitrogen, a relatively nonreactive molecule that is metabolically useless to all but a few microorganisms.
Neurotransmitters are the chemical molecules, which help in transfer of the signals from one neuron to another. Inside the neurons, the signals are transferred as electrical signals, but at junction of two neuron, which is known as synapse, the signals are transferred in chemical forms.
These neurotransmitters have a definite shape and are recognized by the receptors present in the receptor site of the succeeding neuron. The neurotransmitters from the synapse binds to the receptor site of the receiving neuron. binding of the neurotransmitter to the receptor causes excitation of the receiving neuron, which also known as postsynaptic neuron.
Hence, Like a key in a lock, the shape of the neurotransmitter must bind with the receptors of the receiving neuron.
<span>The blood pressure measured in the calf is lower than it is in the arm. Blood pressure in the body is highest right at the ascending arch of the aorta. From that point, the pressure decreases as blood moves "distally" from the heart. Purely mechanically, legs are farther away from the heart than are the arms, thus pressure is less.</span>
Because of their resemblance and relationship to prehistoric reptiles and many people think that birds descended from dinosaurs
Answer:
The correct answer will be-
1. Evolutionary unity- DNA
2. specialized cellular modifications- plant cells have chloroplasts and large central vacuole.
Explanation:
<u>Case I
</u>
Evolutionary unity is a concept which explains that all the organisms possess some common structure or universal structure or molecules.
The best characterized evolutionary molecule is DNA molecule which took the role of genetic material in past and is passed on to the daughter cells and still is made up of the same components which are a five-carbon sugar, four types of nitrogenous bases and a phosphate group. This DNA molecule is present in almost every organism except for a few viruses.
<u>Case II
</u>
The specialization of the cellular components depends on the function a cell has to perform which became established in the population. The plant cells depended on the sunlight to prepare food for themselves which was done by the chloroplast organelle which is absent in the animal kingdom.
