What you think of as 'a banana' is a Cavendish, one variety of the species Musa acuminate. It is a triploid organism (3n) with three sets of chromosomes in every somatic cell. The Cavendish cannot be naturally bred; it can only be reproduced by cloning. Explain how its triploid state accounts for its inability to form normal gametes. Discuss how the lack of sexual reproduction might make the species particularly vulnerable to a new pest.

Verified step by step guidance

1. Understand the concept of ploidy: Ploidy refers to the number of sets of chromosomes in the nucleus of a cell. In the case of the Cavendish banana, it is triploid (3n), meaning it has three sets of chromosomes.
2. Examine the implications of triploidy on gamete formation: In sexually reproducing organisms, gametes (sperm and eggs) are typically haploid (1n), containing one set of chromosomes. These gametes are formed through a process called meiosis, where chromosome pairs separate and the cell divides, reducing the chromosome number by half. However, in a triploid organism, the uneven number of chromosome sets (3n) complicates this pairing and separation process, often leading to abnormal gametes that are not viable for fertilization.
3. Relate triploidy to asexual reproduction in Cavendish bananas: Due to the difficulty in producing viable gametes, Cavendish bananas cannot reproduce sexually and rely on asexual reproduction methods, such as cloning. This involves vegetative propagation using pieces of the plant itself (e.g., suckers or cuttings) to produce genetically identical offspring.
4. Discuss the genetic uniformity due to cloning: Since all Cavendish bananas are clones, they are genetically identical. This lack of genetic diversity means that all plants have the same vulnerabilities to diseases and pests.
5. Explain the risk of new pests: The genetic uniformity in Cavendish bananas makes the species particularly vulnerable to new pests or diseases. If a pest or pathogen evolves that can exploit the specific weaknesses of the Cavendish banana, it could potentially wipe out entire plantations, as all plants would be equally susceptible.