The Gymnosperms and Angiosperms are groups of plants with seed, which means that they don’ t necessary acquire water for fertilization. These groups have made adaptations for sexual reproduction on dry land.
1) Gymnosperms (plants with the seeds are not enclosed in an ovary) have developed over the course of its evolution, structures that solved the main limitations present in the Pteridophytes in relation to sexual reproduction, in the terrestrial environment. The main changes that happened as an evolutionary adaptation to dry land are those on the seeds and pollen. The advantages of the seeds are: the storage tissue which sustains growth and a protective coat of the seeds. Seed is enveloped with the layers of hardened tissue which prevents desiccation. This is what frees reproduction from the need for a constant supply of water. <span>The sperm (male gamete) of gymnosperms</span> is enclosed in a pollen grain. Thi structure is protected from desiccation and can reach the female organs without dependence on water. Gymnosperms also developed structures called cupules to enclose and protect the ovule (the female gametophyte) which will develop into a seed upon fertilization.
2) Angiosperms are a group of plants which protect their seeds within an ovary called a fruit. Angiosperms have special evolutionary adaptations. For example, they produce their gametes in separate organs, usually in a flower, so the fertilization and embryo development takes place inside an anatomical structure. That provides a stable system of sexual reproduction largely sheltered from environmental fluctuations like water need.
<span>Thy hyaline cartilage covers and protects the ends of bones at freely movable joints. The hyaline cartilage contains elements that are found commonly in areas such as the ear. It is made this way because it is very elastic allowing the joints it is covering to have more flexibility.</span>
<h2>Modern Abiogenesis Hypothesis</h2>
Explanation:
- American physicists Harold Urey and Stanley Miller consolidated warm water with water fume, methane, smelling salts, and atomic hydrogen. These beat with electrical releases. These parts were intended to recreate the crude sea, prebiotic air, warmth, and lighting
- After seven days they found that basic natural atoms, for example, amino acids had framed
- Hence the Miller-Urey try effectively delivered atoms from inorganic parts thought to have been available on the prebiotic earth
- Hence, the right answer is "Modern abiogenesis hypothesis is based on Oparin- Haldane theory and Miller- Urey experiment"
Answer:
Invasive plants, storms, and natural disasters.
Explanation:
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