About from <span>1.8 to 1.3 million years ago,</span>
Answer:
There are three types of neurons are present i. e. sensory neuron, motor neurons and inter neurons.
Explanation:
Sensory neurons are the nerve cells which is responsible for sending the information from the sense organs such as tongue, nose, skin, ears, and eyes to the spinal cord and the brain while the motor neurons are responsible for the transportation of instruction from the brain and spinal cord to the muscles. The inter neuron helps in communication between motor or sensory neuron and the nervous system.
Answer:
C)
Explanation:
Meiosis creates sex cells (gametes) for sexual reproduction. And the resulting daughter cells have have the number of chromosomes as the parent cell.
Answer: A) Two atoms share electrons so they can fill their outer shells
Explanation: A covalent bond is a type of bond formed by sharing equal number of electrons between two non-metal atoms so that both of them can attain a stable octet or duplet structure of noble gases.
In covalent bonding, there is no loss or gain of electrons between atoms. For example, the formation of chlorine molecule, chlorine atom has seven electrons in its outermost shell, remaining one electron to attain an octet structure of noble gases. Two chlorine atoms share one pair of electron, each chlorine atom donating one electron to form a pair so that each atom in the chlorine molecule attains an octet structure..
