Angiosperms are grouped into monocots and dicots
Answer:
If the paired chromosomes fail to separate during meiosis in the female, then the resulting daughter cells will receive either 2 or no copies of chromosome 21. If the resulting egg with 2 copies of chromosome 21 is fertilized with a normal sperm, the resulting zygote with be trisomy 21
Explanation:
If the atoms that are bonding have identical electronegativities, then it's a completely nonpolar covalent bond. This doesn't happen in the real world unless the two atoms are of the same element. In a practical sense, any two elements with an electronegativity difference less than 0.3 is considered to be nonpolar covalent.
As the difference between the atoms increases, the covalent bond becomes increasingly polar. At a polarity difference of 1.7 (this changes depending on who you ask) we consider it no longer to be a covalent bond and to be the electrostatic interactions characteristic in an ionic compound.
Just so you know, you shouldn't take these values as exact. ALL interactions between adjacent atoms involve some sharing of electrons, no matter how big the difference in electronegativity. Sure, you wouldn't expect much sharing in KF, but there's a little sharing of electrons anyway. There's certainly no big cutoff that happens at a difference of 1.7 Pauling Electronegativity units.
Answer: Systematics
Explanation:
Systematics is the study of diversity of organisms including past and present and relationships among living things. Systematics as analytical approach, help us to understand the diversity and relatedness of both existing and extinct organisms. Systematics is also important in carrying out the conservation issues because, it attempts to explain the biodiversity which is related to different kinds of species and could be used in preservation and protect the endangered animals and plants.
They group together for warmth when it's cold and they also group together in case of threats.