Answer: 16.7%
Explanation: Children and adolescents (ages 6 to 17 years) engage in 60 minutes or more of moderate-to-vigorous physical activity daily as described by the CDC in The Physical Activity Guidelines for Americans (second edition).
However, elementary and high schools usually run from 8 a.m to 3 pm (or 3.30pm in some cases) daily. High school students take six one-hour classes or four 90-minute classes and an hour lunch break daily.
Thus, the CDC recommends 60minutes of physical activities daily, which account to 16.7% of the total class duration (6 hours) per day.
They cannot reproduce outside of a living cell
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.
Cell division, also called mitosis , occurs in multicellular organisms to create tissues, organs and organ systems.
C is the correct answer. The universe is always changing with new stars and more carbon dioxide. Any around 23% isnt new
