Biology: CUET Mock Test - 4 - Class 12 MCQ

Connective also known as sterile parenchyma tissue possesses a vascular strand. This is the tissue that attaches 2 anther lobes together. Since monothecous anthers are made of only 1 anther lobe, it does not have connective.

A genetic material must be both chemically and structurally stable. It must be able to replicate. It should provide scope for the evolutionary changes. But it should also be able to express itself in the form of “Mendelian characters” and not “Bohr’s characters”. These Mendelian characters refer to the three laws that were proposed by Gregor Mendel.

There are three different types of RNA. They are mRNA (messenger RNA), rRNA (ribosomal RNA) and tRNA (transfer RNA). sRNA is a small ribosomal RNA. They are produced by the bacterium. The three different types of RNA are required for the synthesis of protein.

Pollen sacs or microsporangia are present within the anther lobes. Each anther lobe has 2 microsporangia. It’s very rare to see a single microsporangium in an anther lobe. Example-Wolffia.

Recombination frequency is a simple measure that can be obtained by analyzing the progeny of the cross. It can then be used to determine the linkage, genetic maps, and gene density.

The hydrogen atom which is attached to the hydroxyl group on the 2’- C atom of the RNA can be easily deprotonated. The presence of larger grooves in RNA is also a reason for it not being stable under alkaline conditions. But under the same condition, the DNA molecule will be stable for it has smaller grooves which cannot be easily attacked or penetrated.

The role of mRNA is to provide the template strand. The role of tRNA is to bring the amino acids and read the genetic code. rRNA plays the structural and catalytic role during the process of translation.

Amino acids do not have any structural specialties to read a code. Francis Crick came up with an ideology that an adapter molecule will be present. This adapter molecule will be capable of both reading the code and also on binding itself to the specific amino acid.

Recombination frequencies provide an inside on the location of genes on the chromosome. It does not provide any information about the possible functions and hence associated phenotypes of a gene.

Proteins form polypeptide chains by the peptide bond formation between amino acids. Their different folding statures results in the formation of non-covalent bonds as well as the different forms of proteins. Despite these capabilities, proteins lack the ability to generate their replica.

The RNA polymerase binds to the promoter region of the DNA molecule. After the attachment of the RNA polymerase enzyme to the promoter, the process of transcription is being initiated.

The tRNA was known by the name sRNA in its early days. sRNA stands for soluble RNA. This was even before the postulation of the genetic code. But, the role of tRNA as an adapter was assigned much later.

Gynoecium represents the female part of the flower. It consists of a stigma, style and ovaries. The gynoecium is non motile. It’s the pollens that are motile. They fall on the stigma which starts the fertilization process.

Pistil is the free unit of a gynoecium. A pistil has three parts-style, stigma and ovaries. Stigma acts as a landing platform for the pollens. Style is the long tube-like structure that carries the male gamete to the ovaries.

During the termination stage of transcription process, the nascent RNA falls off. This is observed when the polymerase enzyme reaches the terminator region. Following this, the RNA polymerase enzyme also falls off.

The stop codons are UAA, UAG and UGA. These codons are absent in the tRNA molecules. tRNA possesses an amino acid acceptor end which is the site for binding the amino acids. Finally, the anticodon loop of the tRNA contains bases that are complementary to the codes.

If the genes are farther away on a chromosome, their linkage decreases. This allows them to recombine more frequently.

Stigma acts as a landing place for the pollen grains from where the style carries it to the ovaries for the fertilization. Stigma also checks the pollen grain for compatibility or incompatibility.

There are three stages in the transcription process. They are initiation, elongation and termination. Among these three, the stage of elongation is catalyzed by the RNA polymerase enzyme.

The actual structure of the tRNA is actually a compact molecule which appears to be like an inverted L shaped molecule. But, the secondary structure of the tRNA appears to look like a clover leaf shaped structure.

Tightly linked genes are located very close to each other. This renders them unable to recombine frequently. Thus, they exhibit low recombination.

From the Griffith’s experiment related to the transforming principle, we could understand that the genetic material still possessed some stability. Likewise, the genetic material DNA which is present in this case also has the capability to join the 2 complementary strands despite it being heated up under appropriate conditions.

Loosely linked genes are located very far from each other. That allows recombining frequently. Thus, they exhibit high recombination.

DNA is comparatively less reactive than RNA. The 2’-OH group which is present at the nucleotide of the RNA is the reactive group. This makes the RNA highly reactive in comparison to the DNA. RNA is also catalytic and liable. It cannot be easily degraded. Due to these reasons, the conclusion is that that DNA is the better genetic material than the RNA.

Alfred was Morgan’s student. He used the methodology of Morgan to obtain recombination frequencies of genes and thus map them on the chromosomes.

In the case of DNA, thymine is found in the place of uracil. Uracil is found to make a double hydrogen bond with Adenine in RNA. The resistance showed by thymine towards all the photochemical mutations is what makes the DNA more stable.

HGP is an acronym for Human Genome Project. It was a huge initiative that achieved in successfully obtaining the human genome sequence.

Mutations can be seen in both DNA and RNA. But RNA mutates at a much faster pace in comparison to the DNA. This is due to the lack of stability that is seen in RNA. Likewise, the viruses which contain RNA as their genetic material also mutate at a faster rate. Their life span will stand short on the contrary.

DNA is a stable genetic molecule in comparison to the RNA. So, the carriage of the genetic information will be carried out by the DNA. The transmission of the genetic material will be done by RNA as it is comparatively less stable.

DNA is a stable genetic molecule in comparison to the RNA. So, the carriage of the genetic information will be carried out by the DNA. The transmission of the genetic material will be done by RNA as it is comparatively less stable.