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.
A food web does not represent all the links in an actual ecosystem.
Explanation:
A food web is also called food cycle. It is understood by the natural interconnection of chain and their graphical representation. The concept is given by Charles Elton. He mentioned about the concept of food cycles in Animal Ecology but later this food cycle is replaced by food web.
Food web are limited representation of eco system. Ecologists can keep together all life forms broadly into one of the two categories which is called tropic levels. These two categories are autotrophs and heterotrophs
Answer:
A. Month 6 because it had an average of 15.2 hours of sunlight.
Explanation:
Summer Solstice occurs in June, which is the sixth month of the year. Summer Solstice is the longest day of the year, for the Northern hemisphere this is between the 20, 21 or 22 of June, During one of these days, the Northern hemisphere is more exposed to the sun rays giving more hours of sunlight, which means a longer day.
Answer:
level 2 = 3,000 level 3=300
Explanation:
Only 10 percent will be transferred to the next level and 10 percent of 30,000 is 3,000. 10 percent of 3000 is 300
Answer:
The answers are b) Disinfection can occur by physical or chemical mean, c) Disinfectants are used to inhibit or destroy pathogens, d)Endospores and viruses can resist disinfectant treatment and e)Disinfection can be used to treat work surfaces as well as workers (i.e., washing hands)
Explanation:
Disinfection is the process that involves the elimination of microorganisms through the use of chemical or physical agents. Among the physicists are heat, radiation, drying, etc. Chemical disinfectants are oxidizing substances that are used in solution and can be combined with detergents or some organic substances.
However, endospores and some viruses are very resistant to both physical and chemical disinfection. In endospores, this resistance is due to the fact that the protective layer of the spore is impermeable to any oxidizing agent. In viruses, the cytoplasmic membrane is composed of two layers, a hydrophobic and a hydrophilic zone, this influences the resistance to disinfectants.
