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.
Answer:
here are some example of destruction of coral reefs. i didnt really understand what you were asking but hopefully this will help you!!
Explanation:
Reef Bleaching. Reef bleaching occurs when extreme water conditions cause corals to expel the internal microorganisms that give them their vibrant colors. ...
Poison or Dynamite Fishing. ...
Water Pollution. ...
Sedimentation. ...
Careless Tourism.
Answer:
The result of cross two squashes with yellow seeds is an offspring of squash with green seeds -dominant caracter- heterozygous and yellow seeds squashes in a genotype proportion 1:2:1 and phenotype proportion 3:1
Explanation:
The cross of two heterozygous individuals for a characteristic results in an offspring that will have both characteristics in pure and heterozygous form. It is a cross monohybrid which complies with the principle of independent segregation exposed by Mendel.
For the characteristic "seed color" the green color would be G and yellow represented as g.
At the cross of two heterozygous squashs:
- Parents: Gg X Gg
- <u>Punnett's Square</u>:
Alleles G g
G GG Gg
g Gg gg
Offspring:
- A pumpkin of green seeds GG (25%)
- Two pumpkins of green heterozygous seeds Gg (50%)
- One pumpkin of yellow seeds gg (25%)
Genotype proportion 1:2:1
Phenotype proportion 3:1
Answer:
the chemical name is Methanol
Explanation:
Methanol chemical formula is CH3OH
