What happens at the synapse between two neurons?
Synapse is a point of connection where two neurons gets connected or communicated, where one neuron sends information to another target nerve cell. Synapses are electrical or chemical. Electrical is where flow or exchange if ions occurs and in chemical synapse, they communicate using chemical messengers called hormones, or neurotransmitters.
Sensory nerves carry nerve impulses to the axon terminal which releases chemical messengers called neurotransmitters, then they goes through the synapse to reach the dendrite part of another neuron. And, finally these neurotransmitters goes to muscles, glands etc. to carry forward their actions.
When a 12 V battery is connected across an unknown resistor, there is a current of 2.5 mA in the circuit. Find the value of the resistance of the resistor.
Outline a project which aims to find the dominant coat colour in dogs.
Draw the structure for the following compounds.
(i) Ethanoic acid (ii) Bromopentane*
(iii) Butanone (iv) Hexanal.
*Are structural isomers possible for bromopentane?
A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?
How is the sex of the child determined in human beings?
(a) What property do all elements in the same column of the Periodic Table as boron have in common?
(b) What property do all elements in the same column of the Periodic Table as fluorine have in common?
Calculate the number of electrons constituting one coulomb of charge.
What is an homologous series? Explain with an example.
Why is variation beneficial to the species but not necessarily for the individual?
A man with blood group A marries a woman with blood group O and their daughter has blood group O. Is this information enough to tell you which of the traits – blood group A or O – is dominant? Why or why not?
How are water and minerals transported in plants?
What would be the electron dot structure of carbon dioxide which has the formula CO2?
Metallic oxides of zinc, magnesium and copper were heated with the following metals.
Metal | Zinc | Magnesium | Copper |
---|---|---|---|
Zinc oxide | |||
Magnesium oxide | |||
Cooper oxide |
In which cases will you find displacement reactions taking place?
Can the wing of a butterfly and the wing of a bat be considered homologous organs? Why or why not?
How are the modes for reproduction different in unicellular and multicellular organisms?
What is the function of digestive enzymes?
In evolutionary terms, we have more in common with
(a) a Chinese school-boy.
(b) a chimpanzee.
(c) a spider.
(d) a bacterium.
Judge the equivalent resistance when the following are connected in parallel – (a) 1 Ω and 106 Ω, (b) 1 Ω and 103 Ω, and 106 Ω.
Define the following terms.
(i) Mineral (ii) Ore (iii) Gangue
What are the methods used by plants to get rid of excretory products?