In plants, apomixis pertains to plant development

The correct option is "without the gametes having to fuse".

Step-by-step Explanation:

1. Understanding Apomixis:
Apomixis is a type of asexual reproduction in plants that mimics sexual reproduction but occurs without fertilization. The term is derived from Greek words: apo meaning "away from" and mixis meaning "mixing" or "union". Thus, it literally translates to reproduction away from or without the union of gametes.

2. Contrast with Sexual Reproduction:
In normal sexual reproduction, male and female gametes (sperm and egg cells) must fuse (a process called fertilization or syngamy) to form a diploid zygote, which then develops into an embryo. In apomixis, an embryo is formed directly from diploid cells of the ovule (such as the megaspore mother cell, nucellus, or integuments) or from an unfertilized egg cell (parthenogenesis), bypassing the fusion of gametes entirely.

3. Why the other options are incorrect:
- "from root cuttings" and "from cuttings of stem": While these are indeed methods of asexual or vegetative reproduction, they are vegetative propagation techniques and are not referred to as apomixis, which specifically refers to seed formation without fertilization.
- "fusion of gametes": This describes normal sexual reproduction (amphimixis), which is the exact opposite of apomixis.