Test: Biology Minor Mock Test- 5 (March 26) - NEET MCQ

The Miller-Urey experiment, conducted in 1953 by Stanley Miller under the guidance of Harold Urey, is renowned for simulating early Earth conditions. They used a mixture of gases thought to be present in the early Earth's atmosphere and passed electric sparks through it to simulate lightning. This resulted in the formation of several organic compounds, including amino acids, which are the building blocks of life. This experiment provided the first strong evidence that organic molecules needed for life could be synthesized from inorganic components under conditions thought to resemble those of early Earth.

The container where fermentation is carried out is called a bioreactor. It has an aeration system, pH correctors and temperature adjustors. Bioreactors are often large.

Vultures will not be considered as predator. Vultures feed on dead animals on the other hand predators kill or harms the prey for obtaining food.

The phrase “sharing of food” or “sharing of the table” describes commensalism. It is a long-term relationship between two species in which one species derives the benefit while other is neither harmed nor benefited.

Monascus purpureus is Yeast used commercially in the production of blood cholesterol lowering statins. Blood cholesterol is responsible for a number of heart disease.

Food web is formed by interaction between a numbers of food chains having common members. Stability of ecosystem largely depends upon the kinds of food web exists in it for proper flow of energy.

• Chimpanzee is closely related to man. DNA content and DNA matching are the same in both.
• This similarity is more than 99% with chimpanzee whereas 94% with a gibbon.

• Typhoid fever in the human being is caused by Salmonella typhi.
• The pathogen enters the small intestine through food and contaminated water and migrates to other organs through blood

This illustration depicts a photomicrograph of Salmonella typhi bacteria:

Vitamin C is not a direct product of microbial fermentation. While antibiotics, ethanol, and lactic acid are common products of microbial metabolism through fermentation processes, Vitamin C is primarily obtained from fruits and vegetables or synthesized chemically. Microbial fermentation is extensively used in the pharmaceutical, food, and biofuel industries for producing a wide range of valuable products.

The release of toxic haemozoin by the ruptured RBCs during malarial infection accounts for the recurrence of high fever and chill every 3-4 days.

In food chain, each organism has its own role in flow of energy and nutrient cycle. If snakes become extinct the loss will make the biological network imbalanced. Their gene pool will lost forever that results into loss of biodiversity.

• In order to use the DNA for genetic engineering processes, it must be in pure form, free from other macromolecules.
• This is termed DNA isolation and is the pioneer step. Since the DNA is enclosed within the membranes, it is required to break open the cell to release DNA along with other macromolecules such as RNA, proteins, polysaccharides, lipids, etc. and from this mixture, DNA is purified.
• A release of DNA from a cell is achieved by treating the cells or tissues with enzymes such as lysozyme (bacteria), cellulose (plant cells), chitinase (fungus), etc.
• These enzymes degrade cell wall; plasma membrane degrading enzymes like lipase, etc., are also needed. Since yeast is a fungus and fungal cell wall is made of chitin (fungal cellulose), isolation of DNA necessarily requires the use of enzyme chitinase.

• Plasmids renature because they have supercoiled structures that have held the two strands of the helix together during denaturation.
• Chromosomal DNA is not able to renature, however, because its longer strands have become mixed with denatured proteins.

Darwin judged the fitness of an individual by number of offspring the individual produce in particular niche. More the viable offspring formed the more fit the organism in that surrounding.

Mycorrhiza is a mutualistic interaction between fungi and plants. About 80-90 percent of plants rely on mycorrhiza for the uptake of minerals (nitrogen, phosphorous, etc.) from the soil. While plants supply essential nutrients such as sugars to fungi for their proper growth.

The chemical energy of food is the main source of energy required by all living organisms. This energy is transmitted to different trophic levels along the food chain. This energy flow is based on two different laws of thermodynamics:

• First law of thermodynamics, that states that energy can neither be created nor destroyed, it can only change from one form to another.
• Second law of thermodynamics, that states that as energy is transferred more and more of it is wasted.

Fossils are generally found in sedimentary rocks.

Xerophytes are plants that grows in deserts having very less water. Sunken stomata, leaves reduced into spines and CAM photosysnthesis are the characteristicfeatures of these plants. Cuticle is present on leaves to prevent loss of water.

Primary productivity is the rate at which solar energy is converted and stored by the producers per unit area over a time period. It involves the conversion of solar energy into organic substances by photosynthetic and chemosynthetic autotrophs.

Hypersaline lagoons have very high concentration of salt (>100). Some organisms can survive in wide range of salinity. These organisms are calledeuryhaline species.

• Entamoeba histolytica causes Amoebic Dysentery or Amoebiasis in the large intestine of humans.
• Its symptoms include constipation, abdominal pain, cramps and stools with excess mucus and blood clots.

• The unintentional or deliberate introduction of alien (new) species into a habitat cause the aliens to turn invasive and thus causing the decline or extinction of indigenous species.
• They can affect all types of organisms (animals, plants, fungi, and microorganisms) and ecosystems.

Origin of universe is explained by big bang theory. According to this theory, whole universe was concentrated into single sphere. Due to same unknown region, there was explosion in it that forms different galaxies still moving away from each other.

For greater efficiency a food chain must have three to four trophic levels. At each trophic levels loss of energy is very high so very small amount of energy is left after there trophic level.

A detritus food chain begins with dead organic matter. It is made of decomposers which are heterotrophic organism fungi and bacteria.Rhizophora species is a saprophyticheterotrophs.

In most of the food chain of ecosystem only 4 to 5 trophic levels are present because loss of energy at successive levels is very high. Only 10% of energy is transferred to next trophic level.

Evolution is the gradual change of race due to variation is course of time. It is the history and development of race along with variations. Evolution is a continuous process and takes millions of years to evolve a new species.

Gene pool is the sum total of gemone of different organism of a particular species. Reduction of gene pool is mainly caused by genetic drift along with reasons like geographical isolations.

Depending upon the type of the raw material used for fermentation and type of processing different types of alcoholic drinks are obtained. Wine and Beer are produced without distillation.

• Having two antibiotic resistance genes in the same plasmid helps in identifying transformants.
• Transformants take up the plasmid and also integrate it into recombinant DNA.