Which statement is correct concerning the relationship between chromosomes and genes, chromatin, or sister chromatids?

genes are the dna - protein material that make up entire chromosomes.
each unreplicated chromosome consists of two sister chromatids.
each replicated chromosome consists of two sister chromatids.
chromatin is a length of dna in a chromosome that codes for a protein or rna.

The correct answer is: Each replicated chromosome consists of two sister chromatids.

Mitosis is the cell division of somatic cells (all cells except gametes) in which mother cell produce two identical daughter cells with the same number of chromosomes as she had.

During the S phase of interphase, replication occurs and the genetic material of a cell is duplicated. There are still the same number of chromosomes (e.g. in humans 46) but they exist in a X shape structure-two sister chromatids (genetically identical). So, there are 46 chromosomes, but 92 chromatids. Sister chromatids separate during the anaphase of mitosis and each chromatid is then considered a separate, individual chromosome. After division and cytokinesis, the normal chromosome number is restored to the cell.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

c. is the correct answer