Standing crop is defined as:

The detritus food chain (DFC) has at the first tropic level.

Read the paragraph given below and answer the question.
Sutton and Boveri argued that the pairing and separation of a pair of chromosomes would lead to the segregation of a pair of factors they carried. Sutton united the knowledge of chromosomal segregation with Mendelian principles and called it the chromosomal theory of inheritance.The scientist who noted that 'The behaviour of chromosomes was parallel to the behaviour of gene' were:

Process of formation of new species due to change in allele frequency in a population is called:

Arrange the following events of embryonic development in a correct sequence.
A. Formation of morula
B. Implantation
C. Cleavage in zygote
D. Formation of blastocyst
Choose the correct answer from the options given below:

Genes which code for a pair of contrasting traits are

Read the following paragraph and answer the given questions:
DRUGS AND ALCOHOL ABUSE
The drugs, commonly abused are opioids, cannabinoids, and coca alkaloids. Opioids are the drugs, which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract. Heroin, commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. Cannabinoids are a group of chemicals, which interact with cannabinoid receptors present principally in the brain. Natural cannabinoids are obtained from the inflorescences of the plant Cannabis sativa. The flower tops, leaves and the resin of cannabis plant are used in various combinations to produce marijuana, hashish, charas and ganja. Generally taken by inhalation and oral ingestion, these are known for their effects on cardiovascular system of the body. It interferes with the transport of the neuro-transmitter dopamine. Cocaine, commonly called coke or crack is usually snorted. It has a potent stimulating action on central nervous system, producing a sense of euphoria and increased energy. Excessive dosage of cocaine causes hallucinations. Other well-known plants with hallucinogenic properties are Atropa belladona and Datura. These days cannabinoids are also being abused by some sportspersons. Drugs like barbiturates, amphetamines, benzodiazepines, and other similar drugs, that are normally used as medicines to help patients cope with mental illnesses like depression and insomnia, are often abused. Morphine is a very effective sedative and painkiller, and is very useful in patients who have undergone surgery. Several plants, fruits and seeds having hallucinogenic properties have been used for hundreds of years in folk-medicine, religious ceremonies and rituals all over the globe.
Heroine (Smack) which is extracted from the latex of poppy plant is chemically called:

Monochromatic lights of wavelengths \(6 2 0 ~ n m\) and \(6 2 6 ~ n m\), respectively are used to study diffraction at a single slit of aperture \(0 . 7 ~ m m\). The distance between the slit and the screen is 1.8 m . The separation between the positions of the first maxima of the diffraction pattern obtained in the two cases is

A cell of e.m.f 4V and internal resistance \(0.2 \Omega\) is connected to \(1.8 \Omega\) external resistance. The potential difference across the terminal of the cell will be:

When the surface of a metal is illuminated with the light of wavelength 400 nm, the KE of the ejected photoelectrons is 1.68 eV. Then the work function of the metal is (hc = 1240 eV-nm) :

The person with karyotype 44+XXY is suffering from:

Consider the LPP: Minimize \(Z=x+2 y\) subject to \(2 x+y \geq 3, x+2 y \geq 6, x, y \geq 0\). The optimal feasible solution occurs at:

The phenomenon responsible for the blue colour of the sky