Test: Biology - 1 - UPSC MCQ

The Vechur cattle is a rare breed of Bos indicus, named after the village Vechoor in Kottayam district of the state of Kerala in India. Its average length is 124 cm and height is 87 cm, according to the Guineas Book of Records, it’s the smallest cattle breed in the world. Its milk is considered to have medicinal properties. Unlike other cattle, they can resist drought by being hardy towards it.

The correct answer is:

1. Both 1 and 2

Explanation:

1. This statement is correct. Warm-blooded animals have the ability to regulate their internal body temperature, allowing them to remain active in cold environments where cold-blooded animals may struggle due to their reliance on external sources of heat for temperature regulation.
2. This statement is also correct. Cold-blooded animals typically have lower metabolic rates and require much less energy to survive compared to warm-blooded animals, which need to maintain a constant internal body temperature through metabolic processes that require more energy.

Humans are diploid organisms by having two members or homologous chromosomes in a pair. Total 23 pairs of chromosomes exist in each somatic cell of the body. Total 46 chromosomes occur. One particular pair individually in male and female determines their respective sex. This one pair is XX in females and XY in males. All the 46 chromosomes in pairs can be seen under microscope at metaphase stage in the cells which are undergoing mitosis.

Octopus belongs to Mollusca.

Jellyfish belongs to Coelenterata.

Silver fish belongs to Arthropoda.

Bombay Duck belongs to Pisces.

X-Ray technique, C14 and Dyer technique is a very important technique for a permanent change in DNA. But in coal miner, C14 amount is very very less. So, there is no risk of change in DNA.

A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. Some genes act as instructions to make molecules called proteins.
An allele is a variant form of a gene. Explained in greater detail, each gene resides at a specific locus (location on a chromosome) in two copies, one copy of the gene inherited from each parent. The copies, however, are not necessarily the same. When the copies of a gene differ from each other, they are known as alleles. A given gene may have multiple different alleles, though only two alleles are present at the gene’s locus in any individual.

Explanation:
The correct option is Option B: 1 only. Let's examine each statement in detail:
1. Frogs can breathe by lungs as well as skin: This statement is correct. Frogs have a unique respiratory system that allows them to breathe through both their lungs and their skin. They have lungs that they use for breathing on land, but they also have a thin and permeable skin that allows them to absorb oxygen from the surrounding environment, particularly in water. This dual breathing mechanism is especially important for frogs that live in aquatic environments.
2. Gills are not present in any stage of lifespan of frogs: This statement is incorrect. While it is true that adult frogs do not have gills, gills are actually present in the early stages of a frog's life. Frog eggs are usually laid in water, and the embryos that develop inside the eggs have gills that they use to extract oxygen from the water. As the tadpoles hatch and grow, they gradually develop lungs and lose their gills. Eventually, they metamorphose into adult frogs that rely solely on lungs for respiration.
In conclusion, only statement 1 is correct, and statement 2 is incorrect. Therefore, the correct answer is Option B: 1 only.

Humans are diploid with 23 pairs of chromosomes. Of this, 22 pairs are somatic and the one pair is sex chromosomes. This particular pair exists as XX in human females and XY in males. The presence of two X chromosomes contributes to the female phenotype while presence of only one Y chromosome is responsible for the human to be male. Females produce only X-type haploid gametes and males produce two types (X and Y) of haploid gametes. Fusion of either X or Y of male gamete with the female gamete determines the sex of the offspring.

After the removal of wastes from the kidneys, the cleaner blood is sent back through the renal veins. From Bowman’s capsule, the filtered liquid passes through tiny tubes where much of the glucose is reabsorbed and sent back to the blood in the renal vein.

Alcohol acts as a diuretic. It actually promotes urine production by inhibiting the release of antidiuretic hormone, or vasopressin from the pituitary gland. In turn, reduced levels of antidiuretic hormone prevent the kidneys from reabsorbing water and thereby increase urine production.

During exercise, the level of somatotropin goes up. Testes secrete testosterone and females’ adrenal glands secrete progesterone. Stress causes the adrenal glands to release very less amount of cortisol (a steroid hormone) than usual.

Werner Arber along with American researchers Hamilton Smith and Daniel Nathans, had won the 1978 Nobel Prize in Physiology or Medicine for the discovery of restriction endonucleases. For the first time, Feldmann and Marks had demonstrated the production of transgenic plants without invitro step. They just grew the Arabidopsis seeds with the gene containing Agrobacterium tumefaciens. Kary Mullis is the inventor of the technique PCR for in vitro synthesis of DNA fragments. Reverse transcriptase was discovered by Howard Temin and independently isolated by David Baltimore in 1970.

Essential amino acids or indispensable amino acids are those amino acids which cannot be synthesized de novo by any particular organism. In humans also, some amino acids are essential and must be supplied in the diet. The amino acids regarded as essential for humans are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.

Lungs are the organs which actually oxygenate up the blood by exchanging the carbon dioxide to outside and taking up oxygen which comes to them by breathing in by the organism. This oxygen in the blood is then transported to each tissue of the body. Integrated and coordinated works of circulatory and respiratory systems are responsible for this.

In genetic engineering, a DNA segment from any foreign source can be inserted into any other genetic material. The enzymes, called restriction endonucleases, act like scissors that cut apart a particular or specific part of the DNA. This cut out DNA piece can be inserted into other genetic material which has been cut to make space for containing the foreign DNA. The DNA once inserted can be ligated by enzymes known as ligases.

DNA is the core material which constitutes the genetic makeup of an individual. The DNA of every individual shows unique properties of nucleotide bases that renders a particular fingerprint. DNA is found in all types of body cells.
Thus both the statements are correct.

NITI Aayog has decided to focus on five sectors that are envisioned to benefit the most from AI (in solving societal needs): 

Healthcare: Increased access and affordability of quality healthcare. 

Agriculture: Enhanced farmers’ income, increased farm productivity and reduction of wastage. 

Education: Improved access and quality of education. 

Smart Cities and Infrastructure: Efficient connectivity for the burgeoning urban population. 

Smart Mobility and Transportation: Smarter and safer modes of transportation and better traffic and congestion management.

Sternum is the breast bone. Clavicle is the collar bone. Patella is the knee cap. Scapula is the shoulder blade.

Adrenalines are secreted in the situations of exercise, fear or any kind of dangerous situation. Oestrogens are steroid hormones or female primary sex hormones. Insulin is responsible for the metabolism of sugar in the body. Pheromones are the compounds which are secreted generally from insect; go out to affect the other insects. Some of the pheromones include alarm pheromones, food trail pheromones, and sex pheromones.

Ptyalin digests the starch in the mouth. Pepsin is a proteolytic enzyme which breaks down the proteins into simple peptides. Renin is responsible for converting angiotensinogen to angiotensin. Oxytocin is a hormone that stimulates the contraction of smooth muscles of the body.