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.
<em>Because for example one large eagle needs lots of small sparrows to eat. There is usually a food pyramid so for example you could display it along the lines of 1,000 worms are eaten by 20 sparrows which are eaten by 1 eagle. Its just the way things are. It is a fine balance. if you went up to two eagles on same land they would run out of food quickly and then would either starve or have to move on and using up all the food doesnt help them so it needs to be in a fine balance. A balanced ecosystem.</em>
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Yes, natural selection can create different species because over time one species will turn into subspecies and as soon as one subspecies cannot breed with the other subspecies they are no longer the same species. Natural selection creates species through adaption and survival of the fittest, so yes natural selection can create different species.
Answer/Explanation:
D
Trees improve water quality by slowing rain as it falls to the Earth, and helping it soak into the soil. ... Having a buffer of forestland by streams and riverbanks does more than just filtering the water.
Answer:
C
Explanation:
because they are pests and can presents risks to humans
