* 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).
The answer is b. Measure productivity. Good luck!
Without ribosomes, a cell would not produce proteins.
If an animal is having a well developed skeleton system, a backbone then it belongs to vertebrate. Also, size is an important factor to identify vertebrate and invertebrate.
Explanation:
Vertebrates have a well developed skeleton system and backbone. Their skeleton system is made up of bones and cartilage. While, invertebrates don't have any backbone.
Due to lack of backbone or skeleton system, invertebrates are small in size. As there is no proper mechanism to support large body so invertebrates are small in size and also they move very slowly. This is also a major difference in vertebrate and invertebrate.
Another important difference between vertebrate and invertebrate is that body of vertebrate is covered with some structure like hair, feathers, skin, scales or a combination of these.
These features help to distinguish vertebrate from invertebrate by observing them, no need to dissect.
To maintain homeostasis<span> in the blood and extracellular fluid. The most important way that the pH of the blood is kept relatively constant is by </span>buffers<span> dissolved in the blood.</span>
