.Answer:
Option A, fix nitrogen inside nodules on the roots of legumes
Explanation:
Rizhobium bacteria live in symbiotic relationship with roots of leguminous plants such as pulses including alfalfa, soybean etc.
Rhizobium or Bradyrhizobium is a gram negative bacteria that satisfies the nitrogen starvation of host plant.
These bacteria get habitation and nutrition from these leguminous plants and in return they fix the nitrogen into the nodules of the roots. This is a kind of facultative association between soil bacteria rizhobium and legume plants.
Hence, option A is correct
Thus, option A is correct
B. The flower color in a population changes over time.
The right answers are on the attached image.
Baroreflex is a reflex triggered when a baroreceptor is stimulated. In the human body, baroreceptors are found in the carotid sinuses and the sinus of the aorta. These receptors are stimulated during changes in blood pressure. Baroreceptors are sensitive to the stretching of blood vessels.
As blood pressure rises, baroreceptors transmit nerve impulses to the vasomotor center of the medulla oblongata, which is then inhibited. This results in vasodilatation of the blood vessels to reduce blood pressure.
Answer:
Answered below.
Explanation:
The nerve fibres of the autonomic nervous system that connects the ganglia to the the central nervous system are called preganglionic fibres. They are divided into sympathetic preganglionic fibres and parasympathetic preganglionic fibres and both have acetylcholine as their neurotransmitter.
The sympathetic preganglionic is shorter compared to the parasympathetic preganglionic fibres. They originate from the hypothalamus and brainstem and project to the ganglia non the spinal cord. A ganglion is a cluster of nerves outside the central nervous system.
The preganglionic sympathetic fibres originating from T1-T2 innervate the cervical ganglion which innervates the muscles of the pupils (dilators).
The postganglionic fibres originating from the preganglionic fibres of T11-L3 passes through splenic, celiac and mesenteric ganglia to innervate the kidneys and renal vessels.
