Answer:
double fertilization
Explanation:
Flowering plants or angiosperms are seed-producing plants with the ability to produce reproductive organs-flowers and fruits with seed in it (unlike gimnosperms which contain naked seed). Another distinctive feature of angiosperms is their reduced gametophytes. This feature most likely reduces the time between pollination and fertilization. Fertilization in flowerin plants is double, meaning that two sperm cells fertilize ovule cells(egg cell and central nuclei cell): one forms diploid zygote which will develop in embryo, while other form triploid cell which will develop into endosperm (provides nutrition for the embryo).
Answer:
A. aneuploidy; trisomic
Explanation:
Aneuploidy means having more numbers of chromosomes than usual while polyploidy means having an abnormal number of chromosome sets. Down syndrome is a trisomy on chromosome 21 meaning there are 3 chromosomes for chromosome set 21.
4 billion years ago the temperature was much higher due to repeated volcanoes and hot gases present in the atmosphere. There weren't any live forms on earth. ... The atmosphere had a different concentration of gases on the earth. There were no life sustaining gases.
I think that about half of all babies are able to walk independently by 12 month of age. It said that babies tend to take their first steps from the age of 9. Babies usually start to crawl before they can walk. This is because their arm are usually more effective. After crawling they learn to stand up with their feet first and later learn to walk while holding things. The next step after that is walking.
Not all babies walk at the same time. There those that learn before the other so there is no need to worry if your child does not walk by 12 months.
Answer: the earth was just starting to develop really well and well enough for life.
Explanation: atmospheric oxygen and oceanic calcium levels went up, but nobody needs to know that much facts about how earth developed, But the group called phyla started growing because of these conditions
