Answer:
Fossil records help scientists understand about how and when an organism might have evolved. It also helps determine how many evolutionary changes a particular specie might have gone through.
The long-term evolutionary patterns for a specie can be determined by fossils. Fossil record will help us analyze all the evolutionary changes that a species might have gone through to evolve into a particular type.
The gradual evolution of a species can be predicted if the fossil records show small, increment changes in the fossil patterns.
On the other hand, rapid evolution will result when there are no intermediate fossils depicted for a specie. That specie might have aroused due to a sudden change.
Answer:
B
Explanation:
B is the most likely consequence because of the following facts we are told:
- After apple trees were introduced, some apple maggots began feeding from and laying their eggs on apple trees
- Adult apple maggots will only mate on the type of tree on which they were born.
This provides a geographical isolation (because they are feeding and laying eggs on separate trees) and reproductive isolation (because they will only mate on the type of tree on which they are born).
These two factors increase the chances that apple maggots feeding on apple trees will only encounter those who have mated on the same tree, and continue to mate this way. Over time, the populations (i.e. apple tree vs hawthorn tree) will intermix less and less. This will mean the genetic pool will become distinct, and natural selection will be acting differently (different habitats and different genes), encouraging speciation.
Answer:
Hi there!
Your answer is:
It is very important for the cell membrane to be <em>semi-permeable</em> because the ability to pick and choose what comes in and out of the cell keeps the cell safe! The membrane can choose to block out nasty germs and can also choose to get rid of internal waste.
An example of when this is important is in this scenario:
Let's say the cells are in a really salty solution. Naturally, salt will want to pull the water out of the cell. If the membrane <u>wasn't</u><u> </u> semi permeable, the water would listen to the salt and leave the cell. This would cause cell death. <u>BECAU</u><u>SE</u> the membrane is semi permeable, they can choose <em>not</em> to give the salt any water, keeping them alive
Hope this helps
Answer:
The prolonged exposure to cortisol hormone may cause different health problems including anxiety, depression, muscle atrophy, hypertension, metabolic problems, diabetes, myopathies, osteoporosis, etc.
Explanation:
Cortisol is a stress hormone secreted by the adrenal glands, it is a steroid hormone that is involved in diverse functions including the control of metabolic and immune responses, salt balance (blood pressure), etc. Moreover, cortisol hormone also has anti-inflammatory properties. However, prolonged exposure to stress hormones like cortisol is associated with different health problems, especially anxiety and depression.
RFLP or Restriction Fragment Length Polymorphism exploits the variation of homologous DNA (Deoxyribonucleic Acid) sequences. This technique is frequently used in different types of analysis such as genotyping, paternity tests, forensics, hereditary disease diagnostics, and many others. In diagnosing diseases, PCR is use to find the DNA of pathogens in small amounts to diagnose hundreds of genetic diseases. While in forensic investigations, PCR can give a probably ID from 20 cells.
