Answer:
This is true.
Explanation:
More commonly, an X chromosome will die and get replaced by a Y chromosome (all humans start off as females). When this occurs, the substitute Y chromosome causes changes in the zygote to occur; they begin developing male genitalia (i.e. penises, testicles, prostates, etc.).
Answer:
The correct answer will be-
1. Nucleosomes
2. Chromatin
3. Sister chroamtid
4. Centromere
Explanation:
The DNA is a very long molecule which if has to be passed on to the daughter cell as it is will cause problems. So, to reduce problems a cell form tightly packed structure of DNA so that they can be passed easily to the daughter cell.
The packaging of DNA begins with the wrapping of the DNA around histone proteins which forms the 11 nm basic structural units called nucleosomes. The nucleosomes start condensing each other and form 30 nm structure chromatin fibres.
The chromatin fibres undergo replication during S phase which produces an exact copy of the chromatin called sister chromatids bound to each other at a central point called centromere which helps the separation of the chromatids during M phase.
The Beginning of mRNA Is Not Translated
Interestingly, not all regions of an mRNA molecule correspond to particular amino acids. In particular, there is an area near the 5' end of the molecule that is known as the untranslated region (UTR) or leader sequence. This portion of mRNA is located between the first nucleotide that is transcribed and the start codon (AUG) of the coding region, and it does not affect the sequence of amino acids in a protein (Figure 3).
So, what is the purpose of the UTR? It turns out that the leader sequence is important because it contains a ribosome-binding site. In bacteria, this site is known as the Shine-Dalgarno box (AGGAGG), after scientists John Shine and Lynn Dalgarno, who first characterized it. A similar site in vertebrates was characterized by Marilyn Kozak and is thus known as the Kozak box. In bacterial mRNA, the 5' UTR is normally short; in human mRNA, the median length of the 5' UTR is about 170 nucleotides. If the leader is long, it may contain regulatory sequences, including binding sites for proteins, that can affect the stability of the mRNA or the efficiency of its translation.
The part of the Human body that is most similar in function to the spongy mesophyll layer in a leaf is A) Alveoli in the lungs.
Both use oxygen, both produce energy, both give out carbon dioxide as the result and the overall chemical reactions are the same.
Hope this helps :)