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.
the state of having the same or similar relation, relative position, or structure
Answer:
features of living things are -
☆ they can grow and repair
☆ they can respire
☆ they can reproduce
Examples - humans , animals , etc.
hope that helps uhh :)
Answer:
Right here
Explanation:
The renewable resource can be used over and over and replaced very fast to human standers. Nonrenewable resources cannot be made fast enough by human standards.
Answer:
TRUE
Explanation:
Yes this is true that Complex DNA repair mechanisms in many organisms is a challenge to Darwinian evolution because DNA repair is complex involving many proteins and Darwinian evolution would need to evolve all of these proteins simultaneously. The importance of neutral mutations has emphasized by Evolutionary theory.
DNA repair: The process through which cell repairs it's impaired DNA is called DNA repair process.
