When DNA is copied to form chromosomes that have 2 sister chromatids this is called DNA .?

Answer 1

Each chromosome has two arms, labeled p (the shorter of the two) and q (the longer). The p arm is named for "petite" meaning 'small'; the q arm is named q simply because it follows p in the alphabet. (According to the NCBI, "q" refers to the French word "queue".) They can be

Metacentric

A chromosome is metacentric if its two arms are roughly equal in length. In some cases, a metacentric chromosome is formed by balanced Robertsonian translocation: the fusion of two acrocentric chromosomes to form one metacentric chromosome.

Submetacentric

If arms' lengths are unequal, the chromosome is said to be submetacentric

Acrocentric

If the p (short) arm is so short that is hard to observe, but still present, then the chromosome is acrocentric (The "acro-" in acrocentric refers to the Greek word for "peak.").

In an acrocentric chromosome the p arm contains genetic material including repeated sequences such as nucleolar organizing regions, and can be translocated without significant harm, as in a balanced Robertsonian translocation. The domestic horse genome includes one metacentric chromosome that is homologous to two acrocentric chromosomes in the conspecific but undomesticated Przewalski's horse. This may reflect either fixation of a balanced Robertsonian translocation in domestic horses or, conversely, fixation of the fission of one metacentric chromosome into two acrocentric chromosomes in Przewalski's horses. A similar situation exists between the human and great ape genomes; in this case, because more species are extant, it is apparent that the evolutionary sequence is a reduction of two acrocentric chromosomes in the great apes to one metacentric chromosome in humans

Telocentric

A telocentric chromosome's centromere is located at the terminal end of the chromosome. Telomeres may extend from both ends of the chromosome. For example, all mouse chromosomes are telocentric

Holocentric

With holocentric chromosomes, the entire length of the chromosome acts as the centromere. Examples of this type of centromere can be found scattered throughout the plant and animal kingdoms with the most well known example being in the worm, Caenorhabditis elegans.

Answer 2

A chromatid is made of a very long double helix of DNA and the DNA is typically surrounded by histone proteins, especially during the condensed phase

Answer 3

Sister chromatids are made up of two identical copies of a chromosome.

Answer 4

Nah.