The correct answer is B. Sensitive period
Explanation:
In development, the sensitive period refers to a lapse of time in which organisms are more susceptible or receptive to stimuli and therefore during this time there can be great advances in development. Additionally, different from critical periods sensitive periods do not imply irreversible consequence if the stimuli are not presented. For example, in human beings from birth to the age of 6 years, children are more receptive to learn and acquire certain skills such as learning a new language if exposed to it and therefore this can be considered as a sensitive period. Considering this, it can be concluded the definition presented refers to the Sensitive period.
Answer:
The correct answer is option c. "adaptive radiation".
Explanation:
The term "adaptive radiation" is used in evolutionary biology to describe a evolutionary history at which many different organisms are created as a result of a rapid diversification of an ancestral species. This phenomenon takes place as a result of changes in the environmental conditions that forces new species to adapt quickly. The scientist observations of many intermediate forms at different continents of an ancestral reptile, most strongly support the evolutionary model of adaptive radiation.
Answer:
D. the 23rd pair of chromosomes
Explanation:
Humans have a total of 23 pairs of chromosomes. Out of a total of 23 pairs, 22 pairs are autosomes. Autosomes are the chromosomes that carry the genes for all the genetic traits but are not involved in the sex determination of the individuals.
The 23rd pair of chromosomes in humans is of sex chromosomes as these chromosomes carry the genes to regulate the gender of the individuals. A human female has two copies of the X chromosome as sex chromosomes while human males have one X and one Y chromosome as their sex chromosomes. The Y chromosome carries "SRY" gene that codes for testes determining factor and regulates the development of testes in the embryo.
Answer:
The new drug will not be effective against the treatment of cancer.
Explanation:
The drug will not be effective against the cancer treatment because the drug will inhibit the dimerization of receptor tyrosine kinase (RTK) but as the Ras has undergone mutation due to replacement of one amino acid, it will be constitutively expressed and the drug is not effective in stopping the Ras functioning.
Thus, Gefitinib cannot work against the cancerous cell as it is not potent to stop the functioning of mutant Ras protein.
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