Lactose metabolism is regulated by lac operon in prokaryotic cells. When in the environment lactose is present, the cell signals the presence of lactose and synthesizes the enzyme required for the degradation of lactose. Removal of lactose from the environment leads to the termination of the enzyme synthesis. Thus, the metabolism of lactose is environment dependent.
The metabolism of lactose is also dependent on the presence of glucose. Glucose is the favorite food for bacteria. If glucose and lactose both are present in the environment, the bacterial cells prefer glucose over lactose and lactose is not metabolized. In the absence of glucose, the cells will metabolize lactose.
Explanation:
a) The allele for hemophilia is Xh and that for normal is XH.
Crossing a hemophiliac male, Xh Y, with a normal female XH XH,
- XH Xh, normal carrier female
- XH Xh, normal carrier female
- XH Y, normal male
- XH Y, normal male
b) Both parents are normal and children still having hemophilia means that the mother is a carrier.
Let's see how it'll work out if we cross a normal male with a carrier female,
XH Y × XH Xh
- XH XH, normal female
- XH Xh, carrier female
- XH Y, normal male
- Xh Y, hemophiliac male
This means that the possibility of a female being normal, a carrier or not, is 100%. The possibility of a male being normal is 50% and the possibility of him being a hemophiliac is also 50%.
Thus it's possible that all 7 sons get hemophilia as each male baby has a 50% chance of having the genotype Xh Y. And it makes sense that all the females are normal. Those females could have the genotypes XH XH, or XH Xh (carriers).
A decrease in strawberry productivity
Hibernation helps animals survive the changing seasons. Foods that bears eat, such as berries and flowers, are much less available during cold winter months. When they hibernate, bears enter a deep sleep. ... While they sleep, the bears can survive because their bodies live off of their stored fat or food.
During hibernation, the animal’s body temperature, heart rate and breathing rate all drop to significantly lower levels. Animals do this to survive the winter because the weather is cold and food is scarce. It is advantageous because these animals can quite literally shut themselves off for weeks at a time rather than try and survive through harsh weather conditions.
While many people think bears are hibernators, they actually participate in a similar, though not exact, practice. Instead of hibernating, bears fall into a deep sleep called torpor. During torpor, heart rate and breathing rate decreases, body temperature reduces slightly and bears do not eat or release bodily waste. Bears can sleep more than 100 days without eating, drinking, or passing waste!
Bears sleep in dens that they make themselves, as well as in hollow trees, caves and dens built by other bears. A den can be built in 3–7 days, however, the timing of den building varies from bear to bear. While some bears build their dens months before hibernation season, others choose to excavate their dens.
These animals can dramatically drop their body temperature to below freezing—salty body fluids work to prevent tissue crystallization in particularly cold temperatures.
So really, animals that are true hibernators don’t actually sleep through the entire winter.
The urea produced by their fat metabolism is broken down and the nitrogen is re-used by the bear to rebuild protein.
Answer:
Why is water so important to all living things?
Explanation:
we need water to live
