Answer:
The atomic number or proton number of a chemical element is the number of protons found in the nucleus of every atom of that element. The atomic number uniquely identifies a chemical element. It is identical to the charge number of the nucleus.
Explanation:
<u>Answer:</u>
Discovery of vaccine for smallpox, viruses and actual organisms that cause many diseases lead to the development of Germ Theory.
<u>Explanation:</u>
- Theory was the 'predominant theory' of 'disease transmission' before germ theory but it is no longer accepted as a 'scientific theory' of diseases.
- 'Formal and reliable experiments' on germs and diseases relationship were 'conducted by Louis Pasteur'.
- He showed that growth of microorganisms was not a spontaneous generation and his pasteurization experiment provided key pieces of evidence that supported germ theory.
Answer:
B. The father did not contribute a sex chromosome to his daughter due to nondisjunction of the sex chromosomes. The daughter is XO and her only X chromosome came from her mother, who was a carrier.
A.The mother's X chromosomes failed to separate during meiosis, and the daughter inherited two X chromosomes with the Lesch-Nyhan mutation. The father contributed no sex chromosomes.
Explanation:
As seen in the question above, a little girl was diagnosed with Lesch-Nyhan syndrome, which is an X-linked recessive condition caused by a mutation in the HPRT1 gene responsible for purine metabolism.
The little girl's parents do not have the syndrome, and no one in the little girl's paternal family presented this syndrome, however, we know that the maternal grandfather of the little girl's mother had the syndrome, which means that it was the mother's genetic material that contributed to the development of the syndrome in the little girl. This was because the little girl did not receive any X chromosomes from her father, but she inherited the two X chromosomes from her mother that coded for the Lesch-Nyhan mutation. This happened because the mother's X chromosome disjuction did not occur during meiosis I.
As shown above, the father did not contribute any sex chromosomes to his daughter, which means that the daughter is XO and her only X chromosome came from her mother, who was a carrier.
Answer:
Schooling
Explanation:
Schooling is a collective activity that is far more prevalent in bony fish than cartilaginous fish.
Schooling is a term used to describe collective activity in fish. For example, if a group of fish swims in the same direction in a coordinated fashion, they are schooling.
- Fish schools are one example of animal aggregation.
The valence electrons of carbon are important because the valence give an element their bonding properties. If Carbon did not have as many, it would not be able to bond four times. or have many of the properties it possess.
