Answer:
radiometric dating methods
Explanation:
The oldest rock layer will be at the very bottom, and as time goes on, more layers will form making the top layer the youngest layer and the bottom layer the oldest. This method can determine the amount of radioactive decay of certain elements which can help them make a geologic time scale.
Answer:
Angiosperms have seeds with an 3n endosperm due to double fertilization.
Explanation:
- Double fertilization is found only in flowering plants.
- In angiosperms, the female gametophyte does not grow after reaching eight nucleate stage.
- After fertilization and triple fusion, the zygote and primary endosperm are created and further growth of embryo sac continues.
- Triple fusion is the fusion of two haploid polar nuclei of female gametophyte and one male nuclei. This results in a 3n nucleus.
- The developing embryo obtains nutrition from the endosperm.
- If fertilization fails no endosperm is formed.
A compound is a molecule made of atoms from different elements. All compounds are molecules, but not all molecules are compounds. Hydrogen gas (H2) is a molecule, but not a compound because it is made of only one element. ... Atoms that share electrons in a chemical bond have covalent bonds.
Answer:
Explanation:
In this lesson we will learn the three basic parts of all cells. Cells have something called a cell membrane, a nucleus, and cytoplasm.
