humans have pairs of chromosomes

In the diploid number, chromosomes are always found in pairs. In each pair there are two identical chromosomes, called homologous chromosomes. These chromosomes are identical in size, appearance and position of the centromere. Apart from t..

As can be seen from the human karyogram, the chromosomes are classified into two types, autosomes and sex chromosomes. The autosomes have homologous chromosomes as pairs whereas the sex chromosomes are of two different types - X and Y. A ..

Waldeyer is credited with the discovery of chromosomes in the year 1888 within the nucleus. He observed them as darkly stained bodies. However, it was the American William Sutton who noticed the similarities between the behaviour of the mendelian factors or genes and that of the chro..

It has been noted that in the dihybrid genetic crosses, a recombination frequency of less than 50% indicates linkage of the two genes involved. Morgan and Sturtevant found that the recombination frequency varies for different mutant gene pairs. The difference in the recombination fr..

Chromosome Mapping - It has been noted that in the dihybrid genetic crosses, a recombination frequency of less than 50% indicates linkage of the two genes involved. Morgan and Sturtevant found that the recombination frequency varies for different mutant gene pairs. The differenc..

. Such a chromosome assumes the shape of 'V' during anaphase. Sub-metacentric, where the centromere is slightly away from the centre and hence the two arms are unequal. Such a chromosome attains the shape of 'L' during anaphase. Acrocentric, where the centromere is situated far ..

Summary - Chromosomes are tiny thread-like structures found in the nucleus of a cell. Chromosomes store and transmit the coded information which is responsible for all the life processes of an organism. Hence, chromosomes are commonly described as carriers of heredity...

The idea of independent assortment can be explained as follows: 1. Let us think of two pairs of contrasting characters represented by the alleles R and r, Y and y. There are two ways by which the two homologous chromosomes segregate during metaphase I of first meiosis. This in t..

It is a comprehensive international effort started in 1990 by molecular biologists to map the entire human genome by determining the complete nucleotide sequence of DNA of each chromosome..

There are a pair of lungs in the thoracic cavity - the left lung and the right lun..