Because it has different important things inside to make the cell do it’s job
Sun provides energy to plants, which use it to make food from soil nutrients, which is eaten by animal, which is eaten by another animal, that produces waste and die, that decomposes and adds nutrients to the soil, which plants use with sunlight to make food from soil
Chromosome count of the stem cell that produces the gametes 96
Answer:
directional selection
Explanation:
The directional selection is a type of Darwinian selection where a particular phenotype is favored in the population, thereby modifying the allelic frequencies to increase the proportion of the favored phenotype. <em>Biston betularia</em>, also known as peppered moth, is a species that was influenced by directional selection in its recent past. Before the industrial revolution, the frequency of light-colored moths was predominant compared to the darker-colored phenotypes, because this color has higher adaptive fitness in a clean, no pollution environment, thereby light-colored moths were able to avoid predatory birds. However, during the industrial revolution, the frequency of dark-colored moths increased in response to pollution (i.e. darker environment), thereby conferring a higher adaptive fitness to darker phenotypes.
Answer:
- The lac operon can be activated by the binding of allolactose to the repressor protein, releasing it from DNA and thereby allowing for transcription to occur.
- In response to low glucose levels, cAMP is upregulated; the binding of cAMP to the cAMP receptor protein triggers the activation of the operon.
Explanation:
Lactose operon or lac operon (includes lacZ, lacY and lacA genes) is found in some bacteria and the products of its genes are involved in lactose metabolism. So, this operon is active (genes are transcribed) when lactose is present and glucose is absent (or at low level). The operon is regulated by the lac repressor which acts as a lactose sensor and catabolite activator protein (CAP) which acts as a glucose sensor.
When there is lactose (in the form of allolactose) lac repressor detects it and stops being repressor. This enables transcription.
CAP detects glucose (via cAMP) and activates transcription when glucose levels are low.
