Other Biology Answers

The membrane potential of a neuron is measured from the inside of the cell relative to the outside. For a newly discovered neuron with properties that are not yet known, a researcher measures that the outside of this neuron is 60 mV more positive compared to the inside. What is the membrane potential?

At the moment of fertilization a female egg is about 100μm in diameter. Assuming that each lipid molecule in the plasma membrane has a surface area of 10-14 cm2 , how many lipid molecules are there in the egg plasma membrane if 25% of the surface is protein? (3 marks)

b. Each fertilized egg cell (zygote) divides 30 times to produce all the eggs that a female child will need in her lifetime. One of these eggs will be fertilized giving rise to a new generation. If lipid molecules are never degraded, how many lipid molecules have you inherited that were synthesized in your grandmother? Assume for calculation purposes that the lipid molecules synthesized by your grandmother is equally divided between the daughter cells at each cell division.

Polymerase chain reaction (PCR) is a revolutionary method invented by Kary Mullis in the 1980s which copies the target sequence defined by a pair of primers exponentially. Can exponential amplification of any random sequence of DNA be achieved in PCR with only single primer? Hint: Refer the schematic in the diagram that represents randomly amplified polymorphic DNA (RAPD) marker technology. You can substantiate your answer with help of this diagram, if required.

Please describe what each of these bones are and do.

fixed joint, pivot joint, synovial joint, ball and socket joints and hinge joint


Thank you.

One of the ingredients present in the venom of Indian spectacled cobra, Naja naja is phospholipase A2(PLA2). We have discussed the site of action of PLA2 in a glycerophospholipid. PLA2 from cobra venom thus degrades the glycerophospholipids present in the cell membrane leading to cell lysis releasing its cytoplasmic contents.

a. Explain taking an example of any glycerophospholipid present in the cell membranes, how action of PLA2 brings out lysis

What would be the magnification of a specimen viewed with a compound light microscope that has an objective power of 10x and an ocular lens power of 5x?


5x


15x


500x


50x

4. An advantage of electron microscopes compared to light microscopes is that electron microscopes


are inexpensive and commonly used in most biology laboratories


allow you to view living cells, while light microscopes do not


have higher resolution that allows you to view smaller specimens


allow you to view the true colors of the specimens being viewed

.To study the details of protein molecules on the surface of a cell, a biologist would likely use a


scanning electron microscope


transmission electron microscope



compound light microscope


dissecting microscope