Variations caused by mutation, as proposed by Hugo de Vries, are:

NEET-2019 Evolution [class-xii ]

• random and directionless
• random and directional
• small and directional
• small and directionless
Correct Option: A  [ random and directionless ]

Remark:

n a species, the weight of newborn ranges from 2 to 5 kg. 97% of the newborn with an average weight between 3 to 3.3kg survive whereas 99% of the infants born with weights from 2 to 2.5 kg or 4.5 to 5 kg die. Which type of selection process is taking place?

NEET-2019 Evolution [class-xii ]

• Stabilizing Selection
• Directional Selection
• Disruptive Selection
• Cyclical Selection
Correct Option: A  [ Stabilizing Selection ]

Remark:

Match the hominids with their correct brain size :

NEET-2019 Evolution [class-xii ]

• (A)-(III), (B)-(I), (C)-(IV), (D)-(II)
• (A)-(III), (B)-(II), (C)-(I), (D)-(IV)
• (A)-(III), (B)-(IV), (C)-(I), (D)-(II)
• (A)-(IV), (B)-(III), (C)-(I), (D)-(II)
Correct Option: C  [ (A)-(III), (B)-(IV), (C)-(I), (D)-(II) ]

Remark:

Identify the correct pair representing the causative agent of typhoid fever and the confirmatory test for typhoid.

NEET-2019 Human-Health-and-Disease [class-xii ]

• Salmonella typhi/Widal test
• Salmonella typhi/Anthrone test
• Streptococcus pneumoniae/Widal test
• Plasmodium vivax/UTI test.
Correct Option: A  [ Salmonella typhi/Widal test ]

Remark:

Concanavalin A is:

NEET-2019 Human-Health-and-Disease [class-xii ]

• an alkaloid
• a lectin
• an essential oil
• a pigment
Correct Option: B  [ a lectin ]

Remark:

Which of the following immune responses is responsible for rejection of kidney graft?

NEET-2019 Human-Health-and-Disease [class-xii ]

• Cell-mediated immune response
• Inflammatory immune response
• Humoral immune response
• Cell-mediated immune response
Correct Option: A  [ Cell-mediated immune response ]

Remark:

Drug called 'Heroin' is synthesized by:

NEET-2019 Human-Health-and-Disease [class-xii ]

• methylation of morphine
• glycosylation of morphine
• acetylation of morphine
• nitration of morphine
Correct Option: C  [ acetylation of morphine ]

Remark:

What triggers activation of protoxin to active Bt toxin of Bacillus thuringiensis in boll worm?

NEET-2019 Strategies-for-Enhancement-in-Food-Production [class-xii ]

• Body temperature
• Moist surface of midgut
• Acidic pH of stomach
• Alkaline pH of gut
Correct Option: D  [ Alkaline pH of gut ]

Remark:

Select the incorrect statement:

NEET-2019 Strategies-for-Enhancement-in-Food-Production [class-xii ]

• Inbreeding selects harmful recessive genes that reduce fertility and productivity
• Inbreeding increases homozygosity
• Inbreeding is essential to evolve purelines in any animal
• Inbreeding helps in accumulation of superior genes elimination of undesirable genes
Correct Option: A  [ Inbreeding selects harmful recessive genes that reduce fertility and productivity ]

Remark:

Match the following organisms with the products they produce:

NEET-2019 Microbes-in-Human-Welfare [class-xii ]

• (A)-(II), (B)-(IV), (C)-(V), (D)-(III)
• (A)-(III), (B)-(IV), (C)-(V), (D)-(I)
• (A)-(II), (B)-(IV), (C)-(III), (D)-(V)
• (A)-(II), (B)-(I), (C)-(III), (D)-(V)
Correct Option: C  [ (A)-(II), (B)-(IV), (C)-(III), (D)-(V) ]

Remark: