Answer:
Uno de los progenitores es heterocigoto para color naranja (Nn) y el otro parental es homocigoto recesivo para gris (nn). Al haber una cruza entre un homocigoto recesivo y un heterocigoto, la 50% de la progenie expresa color naranja (Nn), mientras que el otro 50% expresa color gris (nn).
Explanation:
<u>Datos disponibles:</u>
- Cruce entre peces naranjas y peces grises
- 50% de la F1 son peces grises
- Naranja dominante sobre gris
Podemos nombrar el alelo dominante para color naranja <em>N</em>, y al alelo recesivo para color gris <em>n</em>.
Para que en un cruce entre dos fenotipos distintos, el 50% de la primer camada exprese uno de estos fenotipos, entonces uno de los parentales debe ser heterocigoto, mientras que el otro parental debe ser homocigoto recesivo. De esta forma 50% de la primera generación expresara uno de los fenotipos, mientras que el otro 50% expresará el otro fenotipo.
Supongamos que uno de los parentales lleva el genotipo <em>Nn</em>, y el otro parental es <em>nn</em>.
Cruce:
Parental) Nn x nn
Gametas) N n n n
Fenotipos) Naranja Gris
Cuadro de Punnett) N n
n Nn nn
n Nn nn
F1) 2/4 = 1/2 = 50% de la progenie tendrá genotipo heterocigoto, Nn
2/4 = 1/2 = 50% de la progenie tendrá genotipo homocigota recesivo,
nn
50% de la progenie será color naranja (Nn)
50% de la progenie será color gris (nn)
The "Spanish" influenza pandemic of 1918–1919, which caused ≈50 million deaths worldwide, remains an ominous warning to public health. Many questions about its origins, its unusual epidemiologic features, and the basis of its pathogenicity remain unanswered. The public health implications of the pandemic therefore remain in doubt even as we now grapple with the feared emergence of a pandemic caused by H5N1 or other virus. However, new information about the 1918 virus is emerging, for example, sequencing of the entire genome from archival autopsy tissues. But, the viral genome alone is unlikely to provide answers to some critical questions. Understanding the 1918 pandemic and its implications for future pandemics requires careful experimentation and in-depth historical analysis.
<span>C. Gametes are the sex cells, and each (sperm and ovum) contain half of the parent's genetic material. These cells will fuse to produce a zygote, which will usually contain the full number of genes required by an organism to live. If there is a chromosomal abnormality, such as a gamete with an extra chromosome, the offspring can either die in development or sometimes be born with physiological and/or developmental difficulties. An example of this phenomenon is trisomy 21, also known as Down Syndrome, in which the 21st chromosome bears 3 copies instead of the regular 2.</span>
Answer:
A. Chemical modification may allow for extended drug capacities such as expanded spectrum of activity and increased stability.
Explanation:
Any modification in antibiotic structure and chemical will affects its ability in a way to increase it capability of target microbes and act efficiently. These modification can increase half life and stability of the drug.
