Answer:
The correct answer will be option-C
Explanation:
The rhythm of the heartbeat is controlled by the pacemaker of the heart called the sino-atrial node.
The SA node generates action potentials which trigger the contraction and relaxation of the atrium and ventricles. The membrane potential generation initiates by the depolarization of the cell membrane when the L type of Ca⁺² ions opens up and calcium ions enter the cell.
This depolarizes the cell until the potential threshold is reached which lies between the -40 and -30 mV.
Thus, Option-C is the correct answer.
Answer:
Parents: Yellow (Aarr) and Grey (AaRr)
Explanation:
Given:
allele A = yellow
allele R = black,
Heteroozygous = gray
Genotypes of the parents:
yellow (Aarr) - female
gray (AaRr) - gray
cross between these
Parents: Yellow (Aarr) and Grey (AaRr)
Gametes: (Ar, ar) and (AR, Ar, aR, ar)
F1 (Punnet square)
----|----- AR ------|------- Ar ------|------ aR -----|----- ar
Ar | AARr (gray) | AArr (yellow) | AaRr (gray) | Aarr (yellow)
ar | AaRr (gray) | Aarr (yellow) | aaRr (black) | aarr (cream)
Ratio: 3/8 yellow : 3/8 gray : 1/8 cream : 1/8 black
Answer:
Option B
Explanation:
Flight-or-flight response is a response or physiological reaction towards external stimuli. Systematic desensitization is a methodology to control anxiety during speech. Hence, these two are not relaxation techniques. Transforming novelty into familiarity is also a methodology to remain prepared during a speech by practicing it well. Visualization is a technique that helps our mind to relax by using imagination to reach a relaxed state of mind.
Hence, option B is correct
Answer:
Winding mills are made on hills because of air flow and currents.
Explanation:
Winding mills capture wind to turn blades and produce energy. In order to do so, it needs winds! Strong winds, in order to turn the blades. You will notice that if you ever scale a mountain or go higher, it starts to become windier/the wind blows harder.
If the wind mills are placed higher, it can capture these windier conditions, thus moving the wind blades to produce energy. The higher the hill, the stronger the wind current, the more energy it produces.
Answer:
Hormones can be proteins, lipids or cholesterol-based molecules. Neurotransmitters are protein. The main difference between hormones and neurotransmitters is that Hormones are produced in the endocrine glands and released into the bloodstream where they find their movement targets at a distance from their origin. In contrast, Neurotransmitters are released into the synaptic space by a terminal of an excited presynaptic nerve cell and transmit a nerve signal to the neighboring postsynaptic nerve cell.
Explanation:
