The Two Highest Levels of the Atmosphere Contain Only Small

question 47

Multiple Choice

The two highest levels of the atmosphere contain only small amounts of oxygen,nitrogen,and ozone.These layers are the

• A)mesosphere and thermosphere.
• B)thermosphere and stratosphere.
• C)stratosphere and troposphere
• D)thermosphere and troposphere.

---

Definitions:

Nuclear Envelope

The double-membraned structure that encloses the nucleus of a cell, separating its contents from the cytoplasm.

Prometaphase

A stage of mitosis where the nuclear envelope breaks down, and the spindle fibers attach to the kinetochores of chromosomes.

Centromeres

The region of a chromosome where the two sister chromatids are joined, playing a crucial role in the movement of chromosomes during cell division.

Sister Chromatids

Identical copies formed by the replication of a chromosome, with both copies joined together by a common centromere.