NEET Unit Test - 6 - NEET MCQ

The assertion (A) states that if an electron is not deflected when moving through a certain region of space, then no magnetic field is present in that region. This statement is false because an electron moving parallel to the magnetic field lines would not be deflected, even though a magnetic field is present. Additionally, if the electron's velocity is such that the magnetic force is balanced by another force, such as an electric field force, there would also be no deflection.

The reason (R) states that the force on an electron is directly proportional to the strength of the magnetic field. This statement is true as the magnetic force on a charged particle is given by the equation F=q(v×B), where q is the charge, v is the velocity of the charged particle, and B is the magnetic field. This indicates that the force is indeed proportional to the strength of the magnetic field.

Therefore, the correct answer is: A is false and R is true.

B₁= μ₀ni/2r₁
B₂= μ₀ni/2r₂
B₁/B₂=r₂/r₁=3/4
r₁:r₂=4/3

In SI units, permeability is measured in Henries per meter H/m or Hm−1.
Henry has the dimensions of [ML²T⁻²A⁻²].
Dimensions for magnetic permeability will be [ML²T⁻²A⁻²]/[L]=[MLT⁻²A⁻²]

The direction of the current will be anticlockwise.

According to Lenz's law, the current in the coil will be induced in the direction that'll oppose the external magnetic field .
As the flux due to the external magnet is increasing ( as the N-pole is brought close ) , the coil will have to induce current in the anticlockwise direction to oppose this increase in flux and not in clockwise direction as that'll end up supporting the external flux.

Given,
Inductance and capacitance are joined in series, and inductance L= 0.5H,
And capacitance C = 8 μF = 8×10⁻⁶ F.
We know that,
ω = 1/√(LC)
ω = 1/√(8×10⁻⁶×0.5)=1/(2×10⁻³) = 500 rad/s

P₄ + N₂O → P₄O₁₀ + N₂

C + 2O₂ → 2CO + CO₂
1 mole

Fajan’s rule

NO₂ + H₂O → HNO₃ + HNO₂
Mixed anhydride

• Transcription is when RNA is made from DNA.
• During transcription, RNA polymerase makes a copy of a gene from the DNA to mRNA as needed. During transcription, the DNA site at which RNA polymerase binds is called the promoter.
• Transcription begins with binding of sigma factor proteins to the RNA polymerase holoenzyme, thus, allowing it to bind to promoter DNA. 
• RNA polymerase creates a transcription bubble, which separates the two strands of the DNA helix and initiates the transcription. 

Transcription in progress: RNA polymerase slides along the DNA and makes an RNA copy (Genes are the only parts of DNA that get copied into RNA):

Hence, the correct option is C.

• The innate tendency of offspring to resemble their parents is called heredity.
• The offspring resembles the parents due to same genetic combination inherited from the parents.

Hence, the correct option is B

• Gregor Mendel is known as the Father of Genetics.
• He experimented on pea plants and discovered the basic inheritance rules. 

Hence, the correct option is A

• The physical appearance of a character or organism's observable characteristics or traits is called as phenotype.
• The genetic makeup of an individual is called genotype. Tallness, round, wrinkled, yellow etc. are due to their genetic makeup.

Phenotype Example:

Hence, the correct option is A

• A part of one chain of DNA molecule known as the sense strand which codes a polypeptide is called cistron.
• Each cistron consists of many codons, and a codon comprises three consecutive nitrogenous bases.

Fig: DNA transcription unit

Hence, the correct option is D.

Three base triplets form a codon that codes for an amino acid. Thus AUG codes for methionine and GUG codes for Valine. AUG and GUG are both initiating codons for translation.

Hence, the correct option is B.

• Genotype of pure tall plant with green pod = TTGG
• Genotype of pure dwarf plant with yellow pod = ttgg
• P generation:  TTGG    X  ttgg
• F1 generation: TtGg (tall plant, green pod)

Selfing: TtGg X  TtGg

As can be seen from the table, a total 4 short plants with genotypes ttGG, ttGg, ttGg and ttgg are produced.

Hence, the correct option is B

A cross between two individuals, one with AB blood group and the other with A blood group will produce four genotypes and three phenotypes.

The genotypes of a husband and wife are I^AI^B and I^Ai.
Four different possible genotypes of their children are: I^AI^B, I^Ai, I^Bi, I^AI^A

The possible number of phenotypes of their children are:

• Blood group A (I^AI^A, I^Ai)
• Blood group B (I^Bi)
• Blood group AB (IAIB)

Fig: Cross between blood groups AB and A 
Hence, the correct option is B.

• F1 pink flowered plants are heterozygous. When selfing is done the genotype and phenotype develops as 1:2:1 as 40 red, 80 pink and 40 white flowering plants.  It is called Incomplete dominance.
• The appearance of a new phenotype in the progeny but not either of the parents is called Incomplete dominance.

Fig: Cross showing incomplete dominance in Mirabilis jalapa

Hence, the correct option is C.

Wolf and Tasmania Wolf are examples of convergent evolution of placental mammals and Australian marsupials. They are evolved differently due to different in climatic and geographic regions.

Human settlement started around 10, 000 years ago due to starting of agriculture. After starting of agriculture, the human civilization started the grows and decline many times.

Common origin of man and chimpanzee is best shown by chromosomes. Both human beings and chimpanzee shows similar kinds of chromosome in terms of number and size.

Among primates Chimpanzee is closet relative to the present day humans.The banding pattern of autosomes 3 and 6 of humans and Chimpanzee is remarkably similar.

There are many evidences that favor the organic evolution of life. According to this concept life originate from pre-existing organisms by evolution in cousr of time. Homologous and vestigial organs hit the uses of different organs in different organism for different purpose.

amount of uranium present

Palaeritological evidences for evolution refer to the fossils. Fossils provide direct and solid evidence in favour of organic evolution through ages. Fossils are studied for knowing about extinct organisms. Birbal Sahni Institute of Palaeobotany is situated at Lucknow. Birbal Sahni is called ‘Father of Indian Palaeobotany’. Age of fossils is determined by Uranium-Lead method (U²³⁸) or Potassium-Argon method or Radioactive Carbon dating (C¹⁴). ESR (electron-spin-resonance method) is the most accurate method of dating of fossils.

Jurassic period of Mesozoic era characterized presence of Gymnosperms as dominant plant and first birds evolved from reptiles. Dianasours are also a kind of reptiles.

The correct option is Option B.

A protobiont is an aggregate of abiotically produced organic molecules surrounded by a membrane or a membrane-like structure. Protobionts exhibit some of the properties associated with life, including simple reproduction, metabolism and excitability, as well as the maintenance of an internal chemical environment different from that of their surroundings. It has been suggested that they are a key step in the origin of life on earth. Experiments by Sidney W. Fox and Aleksandr Oparin have demonstrated that they may be formed spontaneously, in conditions similar to the environment thought to exist on an early Earth.

Protobionts are excitable, metabolically active, inaccurately reproducing protein clusters. These clusters form when their protein parts are mixed with cold water: they self-assemble into microspheres. Protobionts also can release voltage like a neuron because some protobionts store energy through a similar method of membrane potential as organelles. If coated with a semipermeable membrane, a protobiont will swell and contract osmotically when in solutions of differing salt concentrations. The protobiont shares its weak catabolic capabilities with the liposome. They were partially isolated from the environment, but they could not separate combinations of molecules from the surroundings. Other statements are correct and only option B is incorrect.