Answer:
d. Tryptophan would bind to the repressor
Explanation:
However,the repressor would not be able to bind to the operator and switch off transcription.The cell would still be making tryptophan even though it is being supplied by the medium in which it is growing.This is a waste of energy.
They classify on how they reproduce.
Answer:
The human gene for your muscle protein is different from monkey muscle protein in 4 places and different from a chicken's gene in 25 places.
This is molecular biology, and this shows a little bit about evolution because it shows human, monkey and chickens share a common ancestor.
Explanation:
The example shows some features about biology. Molecular biology is focused on all the components and elements of molecular cells. In this case, analysing muscle protein and genes is considering this type biology.
DNA is the origin of every living cell on earth and is unique for every species. The analysis of protein's DNA is a determination of how distant or close species are.
There are many other ways to relate evolution to the different animals, species or cells. You can use fossil record, anatomy, reproductive isolation, embriology, among many others.
Calories in and of themselves aren't a reliable way of describing energy density in food. It doesn't reflect what actually happens in your body (look up bomb-calorimeter for how people figure out calorie content in foods). So based on this, the question is a bit of a non-sequitur. But if you disregard that and go with a regular answer, it really depends on what kind of calories you're ingesting because foods get digested in a function of different amounts of time. Carbohydrates will get digested and converted into glucose almost immediately - being very close to 100% energy efficiency. Fats are the slowest as your body needs to produce bile in order to digest it - not enough bile = undigested fat = unused calories. Proteins are turned into either amino acids (not an energy source per se) or converted into glucose like carbs but instead through gluconeogenesis which is a less efficient form of glucose conversion than carbohydrates (since your liver/kidneys need to produce the enzymes to convert it). The efficiency of protein is likely in the range of 50-60% calories. This is just the tip of the iceberg though - your metabolism also plays a part as to how much and when these calories are either used, stored, and excreted by your body. Ever got the meat sweats? That's your body burning excess energy through thermogenesis when you eat too much protein. So it really depends why you're asking because the answer will differ for each scenario.
