Home
Class 12
BIOLOGY
Assertion The immediate ancestor of pres...

Assertion The immediate ancestor of present day human was Australopithecus.
Reason Australopithecus was discovered from Australia and its cranial capacity was `1150-1300cm^2`,
Which is very close to that of human `1400-1450 cm^3`.

A

Both Assertion and Reason are true and Reason is the correct explanation of Assertion

B

Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion

C

Assertion is true, but Reason is false

D

Assertion is false, but Reason is also false

Text Solution

Verified by Experts

The correct Answer is:
C
The immediate ancestor of present day humans is Honio sapiens fossilis, i.e. Cro-magnon man. They lived about 340000 years ago. Australopithecus was first discovered in Tuang Africa. Its cranial capacity is 500-700 cc, which is equivalent to modern gorilla.
Promotional Banner

Topper's Solved these Questions

  • EVOLUTION OF HUMAN

    ARIHANT NEET|Exercise CHAPTER EXERCISES (COLLECTION OF QUESTIONS ASKED IN NEET &VARIOUS MADICAL ENTRANCE EXAMS)|23 Videos

  • EVOLUTION OF HUMAN

    ARIHANT NEET|Exercise CHAPTER EXERCISES (MEDICAL ENTRANCESS SPECIAL FORMAT QUESTIONS)(STATEMENT BASED QUESTIONS)|10 Videos

  • EVIDENCES OF EVOLUTION

    ARIHANT NEET|Exercise Chapter exercises (Medical entrances gallery)(Collection of questions Asked in NEET & Various Medical Entrance Exams )|58 Videos

  • EXCRETORY PRODUCTS AND THEIR ELIMINATION

    ARIHANT NEET|Exercise Section(C )-Medical entrances gallery|69 Videos

Similar Questions

Explore conceptually related problems

Assertion.Oue present day crop plants are entirely different from their ancestors. Reason. Almost all our present day crops are result of selections carried out by the prehistoric human beings.

A student focuses the image of a candle flame, placed at about 2 m from a convex lens of focal length 10 cm, on a screen. After that, he moves gradually the flame towards the lens and each time its image on the screen. (a) In which direction does he move the lens to focus the flame on the screen? (b) What happens to the size of the image of the flame formed on the screen ? (c ) What difference is seen in the intensity (brightnees) of the image of the flame on the screen ? (d) What is seen on the when the flame is very close (at about 5 cm) to the lens ?

Assertion: GM food which is prepared from GM crops may be more nutritous and good for health than its natural variant Reason :Bacteria present in the alimentary canal of human could take up the antibiotic resistance gene than is present in GM food. The bacteria would then become resistant to concerned antibiotic

When a sound wave enters the ear, it sets the eardrum into oscillation, which in turn causes oscillation of 3 tiny bones in the middle ear called ossicles. This oscillation is finally transmitted to the fluid filled in inner portion of the ear termed as inner ear, the motion of the fluid disturbs hair cells within the inner ear which transmit nerve impulses to the brain with the information that a sound is present. The theree bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle ear to inner ear as shown in the figure below. The area of stirrup and its extent of connection with the inner ear limits the sensitivity of the human ear consider a person's ear whose moving part of the eardrum has an area of about 50mm^2 and the area of stirrup is about 5mm^2 . The mass of ossicles is negligible. As a result, force exerted by sound wave in air on eardum and ossicles is same as the force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of 4xx10^-2Pa from its normal equilibrium pressure value which is equal to 10^5Pa . Frequency of sound wave in air is 332(m)/(s) . Velocity of sound wave in fluid (present in inner ear) is 1500(m)/(s) . Bulk modulus of air is 1.42xx10^5Pa . Bulk modulus of fluid is 2.18xx10^9Pa . Q. This person (without hearing aid machine) is sitting inside a busy restaurant where average sound intensity is 3.2xx10^-5(W)/(m^2) . How much energy in the form of sound is taken up by the person in his meal time of 1 h?

When a sound wave enters the ear, it sets the eardrum into oscillation, which in turn causes oscillation of 3 tiny bones in the middle ear called ossicles. This oscillation is finally transmitted to the fluid filled in inner portion of the ear termed as inner ear, the motion of the fluid disturbs hair cells within the inner ear which transmit nerve impulses to the brain with the information that a sound is present. The theree bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle ear to inner ear as shown in the figure below. The area of stirrup and its extent of connection with the inner ear limits the sensitivity of the human ear consider a person's ear whose moving part of the eardrum has an area of about 50mm^2 and the area of stirrup is about 5mm^2 . The mass of ossicles is negligible. As a result, force exerted by sound wave in air on eardum and ossicles is same as the force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of 4xx10^-2Pa from its normal equilibrium pressure value which is equal to 10^5Pa . Frequency of sound wave in air is 332(m)/(s) . Velocity of sound wave in fluid (present in inner ear) is 1500(m)/(s) . Bulk modulus of air is 1.42xx10^5Pa . Bulk modulus of fluid is 2.18xx10^9Pa . Q. If the person is using an hearing aid, which increase the intensity of given sound wave change as perceived by inner ear?

When a sound wave enters the ear, it sets the eardrum into oscillation, which in turn causes oscillation of 3 tiny bones in the middle ear called ossicles. This oscillation is finally transmitted to the fluid filled in inner portion of the ear termed as inner ear, the motion of the fluid disturbs hair cells within the inner ear which transmit nerve impulses to the brain with the information that a sound is present. The theree bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle ear to inner ear as shown in the figure below. The area of stirrup and its extent of connection with the inner ear limits the sensitivity of the human ear consider a person's ear whose moving part of the eardrum has an area of about 50mm^2 and the area of stirrup is about 5mm^2 . The mass of ossicles is negligible. As a result, force exerted by sound wave in air on eardum and ossicles is same as the force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of 4xx10^-2Pa from its normal equilibrium pressure value which is equal to 10^5Pa . Frequency of sound wave in air is 332(m)/(s) . Velocity of sound wave in fluid (present in inner ear) is 1500(m)/(s) . Bulk modulus of air is 1.42xx10^5Pa . Bulk modulus of fluid is 2.18xx10^9Pa . Q. Find the pressure amplitude of given sound wave in the fluid of inner ear.

When a sound wave enters the ear, it sets the eardrum into oscillation, which in turn causes oscillation of 3 tiny bones in the middle ear called ossicles. This oscillation is finally transmitted to the fluid filled in inner portion of the ear termed as inner ear, the motion of the fluid disturbs hair cells within the inner ear which transmit nerve impulses to the brain with the information that a sound is present. The theree bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle ear to inner ear as shown in the figure below. The area of stirrup and its extent of connection with the inner ear limits the sensitivity of the human ear consider a person's ear whose moving part of the eardrum has an area of about 50mm^2 and the area of stirrup is about 5mm^2 . The mass of ossicles is negligible. As a result, force exerted by sound wave in air on eardum and ossicles is same as the force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of 4xx10^-2Pa from its normal equilibrium pressure value which is equal to 10^5Pa . Frequency of sound wave in air is 332(m)/(s) . Velocity of sound wave in fluid (present in inner ear) is 1500(m)/(s) . Bulk modulus of air is 1.42xx10^5Pa . Bulk modulus of fluid is 2.18xx10^9Pa . Q. Find the displacement amplitude of given sound wave in the fluid of inner ear.

When a sound wave enters the ear, it sets the eardrum into oscillation, which in turn causes oscillation of 3 tiny bones in the middle ear called ossicles. This oscillation is finally transmitted to the fluid filled in inner portion of the ear termed as inner ear, the motion of the fluid disturbs hair cells within the inner ear which transmit nerve impulses to the brain with the information that a sound is present. The theree bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle ear to inner ear as shown in the figure below. The area of stirrup and its extent of connection with the inner ear limits the sensitivity of the human ear consider a person's ear whose moving part of the eardrum has an area of about 50mm^2 and the area of stirrup is about 5mm^2 . The mass of ossicles is negligible. As a result, force exerted by sound wave in air on eardum and ossicles is same as the force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of 4xx10^-2Pa from its normal equilibrium pressure value which is equal to 10^5Pa . Frequency of sound wave in air is 332(m)/(s) . Velocity of sound wave in fluid (present in inner ear) is 1500(m)/(s) . Bulk modulus of air is 1.42xx10^5Pa . Bulk modulus of fluid is 2.18xx10^9Pa . Q. With respect to information provided above, mark the correct statement.