1.
The term chromosome was introduced by
Correct Answer
A. Waldeyer
Explanation
The term "chromosome" was introduced by Waldeyer.
2.
Who had first proved that the genes are carried by the chromosome?
Correct Answer
A. Bridges
Explanation
Bridges is the correct answer because he was the first to provide experimental evidence that genes are carried by the chromosomes. He conducted experiments on fruit flies, specifically studying the inheritance of sex-linked genes. Through his research, Bridges demonstrated that specific genes were located on specific chromosomes, providing crucial evidence for the chromosome theory of inheritance.
3.
The coupling test cross ratio is
Correct Answer
A. 7:1:1:7
Explanation
The given answer, 7:1:1:7, represents the coupling test cross ratio. This ratio indicates the likelihood of certain traits being inherited together. In this case, it suggests that two traits are tightly linked and are likely to be inherited together, while the other two traits are also linked but to a lesser extent. This ratio can be used to understand the genetic linkage between different traits and can be helpful in genetic research and breeding programs.
4.
Hugo de Vries first used the term mutation based on his observation on
Correct Answer
A. Oenothera lamarckiana
Explanation
Hugo de Vries first used the term mutation based on his observation on Oenothera lamarckiana.
5.
Recombination of chromosome takes place in _____ stage of
prophase I of meiosis.
Correct Answer
A. Pachytene
Explanation
During the pachytene stage of prophase I of meiosis, recombination of chromosomes occurs. This is when homologous chromosomes pair up and exchange genetic material through a process called crossing over. This genetic recombination increases genetic diversity and ensures the proper distribution of chromosomes during meiosis.
6.
Biochemical mutants of _____ failed to synthesize certain amino acids.
Correct Answer
A. Neurospora
Explanation
Neurospora is a genus of filamentous fungi that has been extensively studied in genetics and biochemistry. It is known for its ability to grow on minimal media, which is a medium that lacks certain essential nutrients such as amino acids. Biochemical mutants of Neurospora fail to synthesize certain amino acids, indicating that they have mutations in the genes responsible for amino acid synthesis. This makes Neurospora a valuable model organism for studying amino acid metabolism and biosynthesis.
7.
The gametes of Drosophila melanogaster carry
Correct Answer
A. Four chromosomes
Explanation
Drosophila melanogaster, also known as fruit flies, have four chromosomes in their gametes. Chromosomes are structures that contain genetic information in the form of DNA. Gametes are reproductive cells, such as sperm and eggs, that carry half the number of chromosomes as compared to the body cells. In fruit flies, the gametes have four chromosomes, which means that when a sperm fertilizes an egg, the resulting offspring will have a total of eight chromosomes.
8.
Nullisomy is represented by
Correct Answer
A. 2n – 2.
Explanation
Nullisomy refers to the loss of both copies of a particular chromosome in a diploid organism. In this case, the correct answer is 2n – 2, which means that in a diploid organism with a total of 2n chromosomes, nullisomy is represented by the absence of two chromosomes. This is because nullisomy results in a loss of both copies of a specific chromosome, leaving only one copy of each of the remaining chromosomes.
9.
The width of DNA molecule is
Correct Answer
A. 20 Ã…
Explanation
The width of a DNA molecule is 20 Ã….
10.
Double helix DNA model was proposed by _____
Correct Answer
A. Watson and Crick
Explanation
Watson and Crick proposed the double helix DNA model. They are credited with discovering the structure of DNA in 1953. Their model showed that DNA is made up of two strands that are twisted together in a helical shape, resembling a twisted ladder. This discovery was a significant breakthrough in understanding the structure and function of DNA, and it laid the foundation for the field of molecular biology.
11.
RNA is universally present in all organisms except in _____
Correct Answer
A. DNA viruses
Explanation
RNA is universally present in all organisms except in DNA viruses. DNA viruses do not have RNA as their genetic material. Instead, their genetic material is made up of DNA. This is in contrast to other organisms, such as bacteria, algae, and TMV (Tobacco Mosaic Virus), which have RNA as a fundamental component of their genetic material.
12.
MRNA is about _____ of the RNA content of the cell
Correct Answer
A. 3 - 5%
Explanation
mRNA, or messenger RNA, is a type of RNA molecule that carries genetic information from the DNA to the ribosomes, where it is used as a template for protein synthesis. It makes up only a small percentage of the total RNA content in a cell, typically ranging from 3% to 5%. The majority of RNA in a cell is composed of ribosomal RNA (rRNA) and transfer RNA (tRNA), which have different roles in protein synthesis. Therefore, mRNA represents a relatively small fraction of the RNA content in a cell.
13.
In bacterial cell, there are more than _____ tRNAs
Correct Answer
A. 70
Explanation
Bacterial cells have more than 70 tRNAs. tRNA, or transfer RNA, is responsible for carrying amino acids to the ribosome during protein synthesis. Each tRNA molecule is specific to a particular amino acid, and there are more than 70 different types of amino acids found in bacteria. Therefore, there must be more than 70 tRNAs in bacterial cells to ensure that each amino acid is properly transported and incorporated into proteins.
14.
Restriction enzymes are synthesized by
Correct Answer
A. Bacteria only
Explanation
Restriction enzymes are proteins that are produced by bacteria. These enzymes are used by bacteria as a defense mechanism against foreign DNA, such as that from viruses. They recognize specific DNA sequences and cut the DNA at those sites. This ability to cut DNA at specific sequences is used in molecular biology techniques such as DNA cloning and genetic engineering. While other organisms, such as yeast, may have similar enzymes, restriction enzymes are primarily synthesized by bacteria.
15.
Each restriction enzyme cleaves a molecule only at
Correct Answer
A. nucleotide sequence
Explanation
Restriction enzymes are proteins that can recognize and bind to specific nucleotide sequences in DNA. Once bound, they cleave the DNA at or near the recognition sequence, resulting in the formation of smaller DNA fragments. Therefore, the correct answer is "nucleotide sequence" as restriction enzymes cleave DNA molecules only at specific nucleotide sequences.
16.
One of the following process is employed to introduce a foreign gene into a cell
Correct Answer
A. Electroporation
Explanation
Electroporation is a process used to introduce a foreign gene into a cell. It involves the application of an electric field to create temporary pores in the cell membrane, allowing the foreign gene to enter the cell. This method is commonly used in molecular biology and genetic engineering to transform cells and introduce new genetic material. It is a quick and efficient way to deliver genes into cells and has been widely used in research and biotechnology applications.
17.
The number of transgenic plants available to-day are approximately
Correct Answer
A. fifty
Explanation
The correct answer is "fifty". This means that there are approximately fifty transgenic plants available today.
18.
A toxic protein called delta endotoxin is insecticidal and it is produced by
Correct Answer
A. Bacillus thuringiensis
Explanation
Bacillus thuringiensis is the correct answer because it is known to produce a toxic protein called delta endotoxin, which has insecticidal properties. This protein is effective in killing insects and is commonly used in biopesticides for agricultural purposes. Bacillus lactii, Escherichia coli, and Streptomyces griseus do not produce delta endotoxin and are not known for their insecticidal properties.
19.
Pseudomonas putida is a engineered bacterium that can
Correct Answer
A. Digest crude oil slick
Explanation
Pseudomonas putida is an engineered bacterium that has the ability to digest crude oil slick. This means that it can break down and metabolize the components of crude oil, which is a valuable trait in cleaning up oil spills and contaminated areas. This bacterium can play a crucial role in environmental remediation efforts by reducing the harmful effects of oil pollution.
20.
The inherent potential of any living plant cell to develop into entire organism is called
Correct Answer
A. totipotency
Explanation
Totipotency refers to the ability of a single plant cell to develop into a complete organism. This means that a single cell has the potential to differentiate and give rise to all the different types of cells and tissues found in an organism. This concept is important in plant tissue culture and cloning techniques, as it allows scientists to regenerate whole plants from a single cell.
21.
The function of cytokinin is to increase
Correct Answer
A. Cell division
Explanation
Cytokinin is a plant hormone that plays a crucial role in promoting cell division. It stimulates the growth and division of cells, leading to an increase in the number of cells in plant tissues. This hormone is essential for various plant processes such as shoot and root development, leaf expansion, and overall plant growth. Therefore, the function of cytokinin is primarily to enhance cell division in plants.
22.
By the application of tissue culture, one important product is formed
Correct Answer
A. Artificial synthetic seeds
Explanation
Tissue culture is a technique used to grow plants in a controlled environment. It involves taking small pieces of plant tissue and placing them in a nutrient-rich medium to promote growth. One important product that can be formed through tissue culture is artificial synthetic seeds. These seeds are created by encapsulating plant embryos or tissue in a protective coating, allowing them to be stored and transported more easily than traditional seeds. This technology has many applications in agriculture, including the production of disease-free and genetically uniform plants.
23.
The two protoplasts are fused with a fusogen called
Correct Answer
A. Polyethylene glycol (PEG)
Explanation
Polyethylene glycol (PEG) is a fusogen that is commonly used to fuse two protoplasts together. It is a water-soluble polymer that can form a bridge between the membranes of the protoplasts, allowing them to merge and form a single cell. PEG is often used in cell fusion experiments because it is non-toxic and has a high fusion efficiency. This makes it an ideal choice for fusing protoplasts and studying the effects of cell fusion.
24.
Somatic hybrids are produced through
Correct Answer
A. Protoplasmic fusion
Explanation
Somatic hybrids are produced through protoplasmic fusion, which involves the fusion of protoplasts from different plant species or varieties. Protoplasts are plant cells with their cell walls removed, allowing them to fuse together and form a hybrid cell. This fusion can result in the combination of desirable traits from both parent plants, leading to the production of somatic hybrids with improved characteristics. This technique is commonly used in plant breeding to create new varieties with desired traits, such as disease resistance or increased yield.
25.
One of the following organism is a SCP
Correct Answer
A. Spirulina
Explanation
Spirulina is the correct answer because it is a type of cyanobacteria that has been classified as a SCP (Super Color Pigment). SCPs are organisms that produce pigments with unique properties, such as intense color and fluorescence. Spirulina is known for its vibrant blue-green color, which is due to the presence of a pigment called phycocyanin. This pigment has various applications, including food coloring and as a natural dye. In addition to its pigment-producing abilities, Spirulina is also rich in nutrients and is often used as a dietary supplement.
26.
Enriched vitamin tablets are produced from the following organism for human consumption
Correct Answer
A. Spirulina
Explanation
Spirulina is a type of blue-green algae that is rich in vitamins and minerals. It is commonly used as a dietary supplement due to its high nutritional content. Spirulina tablets are produced from this organism for human consumption because they provide a convenient and concentrated source of vitamins.