Answer:
the magnetic direction of rocks along the surface of Earth and the age of rocks along the surface of Earth
Explanation:
The earth's magnetic field or geomagnetic field is believed to originate from the movement of molten iron and nickel in the outer core.
During a period in which the earth magnetic field is normal, crystallising magnetic minerals in magma records the orientation of the prevailing geomagnetic field. At other times when the field reverses and the magnetic field orientation changes, magnetic minerals in cooling magma stores this record.
To create a geomagnetic time scale, geologists can assign absolute ages to the records of these paleomagnetic anomalies which are the reversals. The rock is dated using radiometric techniques and each period of reversal is ascribed an absolute geologic age. Therefore, the magnetic direction of rocks along the surface of Earth and the age of rocks along the surface of Earth helps to build the geomagnetic time scale of the earth.
In order to increase the rate of diffusion of materials in and out of the cell, the following modification can be done to the cell:
1. the shape of the cell can be changed to one that has high surface area to volume ration, for example sphere.
2.The cell can also divide into two in order to increase the surface area to volume ratio.
Answer:
The correct answer will be option-B.
Explanation:
Sertoli cells are the large somatic cells present in the testis which helps in the formation of spermatozoa. The Sertoli cells create a suitable environment for the production and maturation of the sperms as they produce certain molecules which nourishes the sperms.
The Sertoli cells act as a barrier between the testis and blood and secrete enzymes like inhibin. They eliminate the apoptotic germ cells and also produce seminiferous fluid to nourish the sperm. They do not play any role in primary spermatocytes.
Thus, Option-B is the correct answer.
Answer:
bottom of the periodic table
Explanation:
