Respuesta :
* The first statement is true.
Chromatid is a DNA molecule (the nucleofilament) associated with histone proteins and non-histone proteins. A chromatide has the shape of a rod that can have different degrees of condensation depending on the times of the cell cycle or the transcription activity of the genes.
This structural unit appears as a chromosome only during cellular divisions (mitosis or meiosis). The rest of the time, all chromatids form chromatin.
Each chromosome of a cell may consist of one or two chromatids depending on its state: just after a mitosis, or after the second meiotic division, each chromosome consists of only one chromatid, the rest of the time, after DNA replication, each chromosome consists of two completely identical chromatids, connected by the centromere, thus giving the two rods the shape of an X.
* The second statement is True
In its common definition the chromosome consists of one (or more) molecule of DNA, histones and non-histone proteins, disregarding its degree of condensation.
In its most scientifically rigorous definition, a chromosome is a fully condensed structure of chromatin. In this definition, the chromosome is only present during mitosis, more precisely during the metaphase where it takes the name metaphase chromosome (it is during the metaphase that it reaches its maximum degree of condensation).
The sister chromatids of a chromosome contains same set of genes.
Further Explanation:
Cell cycle refers to the sequence of event that takes place whenever the cell is going to divide. These events have to be highly regulated so that the daughter cells formed should have proper cell constituents in the cell.
The cell cycle has the following phases:
1. Interphase- Gap 1, Synthesis phase, Gap 2 phase.
2. M-phase- Mitosis/ Meiosis phase
During the interphase the cell prepares itself for the division to occur. There are also certain checkpoints present in this phase that restricts the cell to proceed further for the next phase until and unless the previous phase has not completed properly.
M-phase is the phase where the chromosomal separation occurs and which is distributed to the daughter cells.A chromosomes consists of sister chromatids that has same set of genes while the non-sister chromatids contains same set of genes but different alleles of gene.
M-phase has different sub stages. They are:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
In the end the cytokinesis occurs and the parent cell divides and give rise to the daughter cell.
Learn more:
1. Learn more about cell https://brainly.com/question/1233693
2. Learn more about DNA replication https://brainly.com/question/1600165
3. Learn more about meiosis https://brainly.com/question/94813
Answer Details:
Grade: College Biology
Subject: Biology
Chapter: The cell cycle
Keywords:
Cell cycle, interphase, Gap 1, Synthesis phase, Gap 2 phase, M-phase, mitosis, meiosis, prophase, metaphase, anaphase, telophase, cytokinesis.
