Ostrich eggshell is composed of 96% crystalline calcite and 4% organic material, mostly proteins. The thickness is made up of three different layers that vary in structure and thickness. The hardness of the shell is 3 on the Mohs scale. Pretty solid!
Answer:
The penis is introduced in a vagina of a female then they start movíng to feel pleasure so the penis throws a Liquid called semen it’s what contains ezpermatozoids that’s what it needs to make a baby
Explanation:
Answer and Explanation:
Tracheophyte plants, also known as vascular plants, are those that possess a supportive tissue that can also conduct fluids -The Xileme- and another tissue that conducts nutritious elements produced by photosynthesis -The Phloem-. These plants have a root (basically underground), a stem (aerial), and leaves. All of them together form the corm. And the corm counts with these vascular tissues to which we referred before.
There are different types of Tracheophyte plants, some of them produce seeds to reproduce and disperse -Spermatophyta- and some others reproduce and disperse by spores -Pteridophyta-. This last seedless group corresponds to ferns and other similar plants.
Pteridophytes characterizes for having a sporophyte that has stems with leaves and a root. It also has primitive xylem composed by tracheids and phloem, both of them formed by vascular bundles located in a central cylinder.
Spores are its dispersion units and are responsible for colonizing new areas. They also constitute the resistance units under extremely unfavorable conditions.
Their life cycle is composed of the asexual phase (sporophytic phase) and the sexual phase (gametophytic).
- The <u>sporophyte</u>, the dominant asexual generation, it is a perennial and diploid structure. Its aerial part might disappear during unfavorable seasons, but it reappears during spring or summer. The sporophyte is in charge of asexual reproduction
- The<u> gametophyte</u>, instead, is and haploid structure, ephemeral and must be in the water for its survival, and for sexual reproduction to be successful. In the presence of water, masculine gametophyte -antherozoids- are released and they swim to the archegonium to meet the ovocell. Antherozoids can swim because they have flagella. After fertilization, a new sporophyte is produced.
Pattern of dark lines or bands that occurs when electromagnetic radiation is passed through an absorbing<span> medium into a spectroscope</span>
Answer: A, B, and C are correct.
Polar attractions are (a) forces between atoms of partial charges.(b) weaker than covalent bond.(c) they are numerous.
Explanation:
Polar attractions take place between atoms with partial charges. They are weaker than covalent bond and numerous of them occur in the living cells. They can form between H and other electronegative atoms like oxygen provided they have strong partial charges.
