Question

1 . basic definition of chromosome chromatic and centromere...how are they different?

2. What are the 4 types of chromosomes

3. The difference btwn autosomes and sex chromosomes

4. Which chromosome has the long arm and the short arm of the X and Y chromosome

5. What is karyotype as how is it made

Answer 1

1. In simplest of terms chromosome is the thread like structure that is present in the nucleus and carry all the genetic information of any species. Chromosome in its normal state is present in compact form i.e. chromosome whereas when it has to replicate its copy or some segment for cellular, metabolic and other purpose it loosens its form that is known as DNA.

When cells divide during mitosis and meiosis , DNA replicates its copy which is known as chromatid. The two copies of DNA is called sister chromatid

Centromere is the specialized structure on the chromosome where two sister chromatids are attached before separating during cell division.

2. The different types of chromosomes are

Lamp brush chromosome

Salivary gland chromosome

B chromosomes/ supernumerary chromosome

Holokinetic chromosomes

3. Autosomes can be defined as housekeeping chromosomes that have all the genes necessary for growth, development  and other functions necessary for survival.

Sex chromosomes are the chromosomes except autosomes present in any species that confwers sex deternination and sex linked traits,

4. X and Y chromosomes have different lengths in humans. X chromosome have equal length of both p and q arms whereas Y chrosomosome has shorter q arm. Many researchers also believe that because of difference in length of arm between the two sex chromosomes at one point of time the Y chromosome will degenerate.

5 Karyotype is understanding and finding out the number and set of chromosomes present in any organism/species. It can be done using various techniques. Conventionally kayrotyping is done using photographic visualization of any organism during different cell divisional stages. Now recently more advanced techniques involve the use of fluorescent dyes like G banding . It is done in systematic order to find the systematic sequence of chromosome in any organism. In karyotyping pair of chromosome are arranged in decreasing order of their length.