Homologous Chromosomes vs Sister Chromatids: Difference and Comparison

All animals contain unique genetic content in chromosomes, and every cell has a unique complement of chromosomes.

These also differ greatly in terms of size, centromere position, spotting qualities, the comparative extent of the forelimbs on each side of both the centromere, and restricted spots along the extremities.

Each chromosome is made up of just one DNA nucleotide. In most cases, chromosomes occur as homologous sets.

Key Takeaways

1. Homologous chromosomes are pairs of chromosomes with the same genes but possibly different alleles, whereas sister chromatids are identical copies of a single chromosome.
2. Homologous chromosomes are inherited from each parent, while sister chromatids are created during DNA replication in the S phase of the cell cycle.
3. Homologous chromosomes separate during meiosis I, while sister chromatids separate during meiosis II and mitosis.

Homologous Chromosomes vs Sister Chromatids

Homologous chromosomes are pairs of chromosomes that are similar in size, shape, and gene content, carrying the same genes that have different versions of those genes. Sister chromatids are identical copies of a single chromosome that are produced during the process of DNA replication.

Homologous chromosomes are that pair during meiosis’s mitotic spindle I. One chromosome inside the pair is of maternal ancestry, and the other is of paternal provenance.

Inside this pair, the chromosome extent and centromere locations are identical. Each duplicate is labeled with the appropriate numeral, which is organized in the same sequence as the original.

As a result, the banding structure of either chromosome inside the pair seems identical.

Sister chromatids are two similar chromatids that culminate in DNA replication throughout the interphase’s Lytic cycle. The centromere is what connects them.

One-half of each cloned chromosome is a sister chromatid. As a result, each duplicated chromosome is made up of two sister chromatids. These are indistinguishable from one another; one is a duplicate of another.

During the prometaphase of mitosis, sister chromatids split from one another.

Comparison Table

Parameters of Comparison	Homologous Chromosomes	Sister Chromatids
Definition	These are a combination of one maternal and one paternal genotype that are partnered together during fertilization in a gamete.	Sister chromatids are multiple versions of the same chromosome that are interconnected together throughout the centromere.
Origin	Several homologous chromosomes in the erotically viviparous genus come first from the father’s gametes, while others arrive from the mother’s.	Each sister chromatid within the physically reproducing sentient species is generated from both the father’s and the mother’s sperm motility.
Similarity	The surface, form, of the centromeres, are similar between homologous chromosomes. They also have the same type of genetic knowledge.	Sister chromatids are the equivalent.
Structure	For the bulk of the cell’s existence, each chromosome is comprised up of one DNA fragment.	Every sister chromatid is constituted up essentially a particular contaminant molecule of DNA.
Connection	Homologous magnetic field lines are unconnected.	The centrosomes join the sister chromatids via collaborative groupings of metabolites.

What is Homologous Chromosomes?

Diploid organisms have two replicas of every chromosome, which are referred to as homologous genomes. The length, structure, and centromere position of the identical homologous chromosomes are all the same.

They also have the same type of hereditary data. One of the homologous alleles in sexually reproducing organisms originates from the father’s spermatozoa and the other via the mother’s zygote.

Two of the above are sex cells defining a person’s gender.

Each chromosome is made out of one DNA strand over the majority of the cell’s existence. The DNA molecule multiplies and creates two daughter cells in anticipation of cell proliferation.

They emerge at a certain stage in the cell’s life cycle and expansion. The centromere is responsible for dividing the chromosome into two branches.

A structure termed a kinetochore is developed, encircling the centromere on the periphery. Its function is to connect microtubules to the partition of chromatids during cell replication.

Each somatic tissue in living beings has 23 pairs of similar chromosomes for a combined amount of 46 chromosomes. Metacentrics are chromatin with equivalent arms.

A chromosome is said to be submetacentric when one of its arms is noticeably larger than the other. There are several acrocentric genomes, which include a secondary clamping that separates a tiny piece known as a satellite.

What is Sister Chromatids?

When a cell proceeds to expand, it must duplicate each one of the chromosomes. Sister chromatids are two instances of the same chromosome.

The sister chromatids are equivalent and are connected by proteins known as grammatical cohesion.

The two daughter cells are linked in the so-called centromere, a DNA region critical to underlying eventual segregation in subsequent phases of embryonic development.

The chromosomes bind to the spindle mechanism via it, which would be a cytoskeletal framework in eukaryotic cells that arises during cell partition. It seeks to distinguish sister chromatids within daughter cells.

Even though the sister chromatids are joined at the center of the cell, they are indeed regarded to be parts of the same chromosome. They split from one another during cellular division.

Then, for every daughter cell, every chromatid gets identified as a different chromosome. Each homolog has two sister chromatids that are kept together through sticky substances termed cohesion just at the chromosome’s telophase.

A sister chromatid has a particular piece of DNA that is equivalent to the DNA strand of the corresponding sister chromatid in about a similar homolog.

Sister chromatids form throughout the ‘S’ period of anaphase and therefore are detached through mitosis. In certain animals, sister chromatids act as DNA repair blueprints.

Main Differences Between Homologous Chromosomes and Sister Chromatids

1. During meiotic division, I, homologous chromosomes enable random chromosomal partitioning and sexual linkage. During the g2 Phase of ovulation and metaphase II of proliferation, sister chromatids enable spontaneous chromatid segmentation and chromosomal crossing.
2. Every chromosome is made up of one DNA compound for the majority of the body’s living. The DNA molecule doubles in preparation for cell division. Whereas in sister chromatids, each sister chromatid is made up of a single DNA chemical compound.
3. Several of the homologous chromosomes in the erotically viviparous genus comes first from the father’s gametes, while the other arrives from the mother’s spermatozoa. On the other hand, every sister chromatid inside a sexually procreating lifeform is derived either from the father’s or the mother’s spermatozoa.
4. Similar or slightly different versions of the identical gene can be found on homologous chromosomes. As a result, the nucleotide sequence is not the same. Except for the chromosomal overlap, sister chromatids have equivalent gene patterns across the chromatids.
5. Homologous poles are not linked. On the other hand, the centromere connects the sister chromatids by enzymes termed cooperative arrangements.

References

1. https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1001006
2. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0003516  

Last Updated : 25 June, 2023