Difference Between Cytoplasmic Inheritance and Nuclear Inheritance

The key difference between cytoplasmic inheritance and nuclear inheritance is that cytoplasmic inheritance takes place from genes present in cytoplasmic organelles while nuclear inheritance takes place from genes present on the chromosomes.

Fertilization is the fusion of male and female gametes together. Therefore, during fertilization, haploid sperm and haploid egg cell unite and form a diploid zygote. Sperm cell transfers its nucleus to the egg cell for the fusion. The resultant zygote has the cytoplasm of the egg cell. In simple words, the cytoplasm of the egg cell becomes the cytoplasm of the zygote. Moreover, the offspring receives genes from both nuclei and genes of the maternal cytoplasmic organelles. Genes of nuclei and genes of cytoplasmic organelles are inherited by the offspring. Therefore, there are two types of inheritance occurring during sexual fertilization. They are cytoplasmic inheritance and nuclear inheritance.

CONTENTS

1. Overview and Key Difference
2. What is Cytoplasmic Inheritance
3. What is Nuclear Inheritance
4. Similarities Between Cytoplasmic Inheritance and Nuclear Inheritance
5. Side by Side Comparison – Cytoplasmic Inheritance vs Nuclear Inheritance in Tabular Form
6. Summary

What is Cytoplasmic Inheritance?

Cytoplasmic inheritance is a type of inheritance which involves DNA of cytoplasmic organelles. In this inheritance, the offspring receives genes from the cytoplasmic organelles (plasma genes or extranuclear genes). Mitochondria and chloroplasts contain genomes composed of DNA. This organelle DNA travels from the mother egg cell to zygote. However, compared to nuclear inheritance, a small number of genes are inherited by the cytoplasmic inheritance. Moreover, it does not follow the Mendelian inheritance pattern, unlike nuclear inheritance.

Furthermore, extra-chromosomal inheritance, extra-nuclear inheritance, somal inheritance and maternal inheritance are several synonyms for cytoplasmic inheritance.

What is Nuclear Inheritance?

Nuclear inheritance occurs due to the genes present on the chromosomes. Therefore, the mother nucleus and father nucleus equally contribute to nuclear inheritance. Moreover, the offspring inherits millions of genes from parents via nuclear inheritance.

Furthermore, this inheritance follows Mendelian inheritance. Nuclear genes can influence genes involved in cytoplasmic inheritance.

What are the Similarities Between Cytoplasmic Inheritance and Nuclear Inheritance?

• Cytoplasmic inheritance and nuclear inheritance are two types of inheritance that describe the transferring of genes from parents to offspring.
• In both inheritance methods, offspring inherit genes.
• Moreover, they are very important processes occurring in living organisms.

What is the Difference Between Cytoplasmic Inheritance and Nuclear Inheritance?

Cytoplasmic inheritance is the transferring of genes present in the organelles of the cytoplasm while nuclear inheritance is the transferring of genes present on the chromosome. Thus, this is the key difference between cytoplasmic inheritance and nuclear inheritance. Another difference between cytoplasmic inheritance and nuclear inheritance is that cytoplasmic inheritance is mostly maternal, while nuclear inheritance is from both maternal and paternal.

Summary – Cytoplasmic Inheritance vs Nuclear Inheritance

Cytoplasmic inheritance is the transmission of genes from the cytoplasmic organelles that occur outside the nucleus while nuclear inheritance is the transmission of genes from chromosomes present inside the nucleus.  Therefore, this is the key difference between Cytoplasmic Inheritance and Nuclear Inheritance.

Reference:

1. “Mitochondrial. “Mitochondrial Inheritance.” World of Microbiology and Immunology, Encyclopedia.com, 2019, Available here.

Image Courtesy:

1. “Mitochondrion structure” By Kelvinsong; modified by Sowlos – Own work based on: Mitochondrion mini.svg (CC BY-SA 3.0) via Commons Wikimedia
2. “The sperm and ovum during fertilization” By Atdoan0 – Own work (CC BY-SA 4.0) via Commons Wikimedia