* The first statement is true.
Chromatid is a DNA molecule (the nucleofilament) associated with histone proteins and non-histone proteins. A chromatide has the shape of a rod that can have different degrees of condensation depending on the times of the cell cycle or the transcription activity of the genes.
This structural unit appears as a chromosome only during cellular divisions (mitosis or meiosis). The rest of the time, all chromatids form chromatin.
Each chromosome of a cell may consist of one or two chromatids depending on its state: just after a mitosis, or after the second meiotic division, each chromosome consists of only one chromatid, the rest of the time, after DNA replication, each chromosome consists of two completely identical chromatids, connected by the centromere, thus giving the two rods the shape of an X.
* The second statement is True
In its common definition the chromosome consists of one (or more) molecule of DNA, histones and non-histone proteins, disregarding its degree of condensation.
In its most scientifically rigorous definition, a chromosome is a fully condensed structure of chromatin. In this definition, the chromosome is only present during mitosis, more precisely during the metaphase where it takes the name metaphase chromosome (it is during the metaphase that it reaches its maximum degree of condensation).
Answer:
First off, we need to establish what secondary consumers are. Primary consumers are all herbivores; they eat the producers. The secondary consumers are on the next trophic level up; they eat the primary consumers. They thus help to control the level/number of primary consumers; otherwise, the number of primary consumers would grow too high, and the producers would all be WIPED OUT.
Now, you may be wondering what controls the amount of secondary consumers? The answer is tertiary consumers. What controls the tertiary consumers? At this point, energy does the job of limiting the population. As you move up trophic levels in an ecosystem, the amount of energy in each trophic level goes down by 90%. So like if you started w/ 1000000 joules of energy in the producer level, that would be 100000 in the primary, 10000 in the secondary, and only 1000 in the tertiary.
The figure shows where mitosis occurs in the cell cycle. after the interphase
