<span>Answer:The blood-brain
barrier (BHE)
BHE is a barrier that's highly permeability selective and protects
the central nervous system from potential dangers like viruses, bacteria and parasytes that may be circulating int he blood. <span>It is composed of endothelial cells, astrocytes, pericytes.</span></span>
<h2>
A change in one base of the gene sequence is known as point mutation.</h2>
Explanation:
Question 2 is incomplete.
3. A mutation that only affects a single nucleotide of nucleic acid is known as Point Mutation.
In Point mutations there is substitution of one base for another.
Example: TAT TGG CTA
TAC TGG CTA
The TAT changes to TAC which shows point mutation.
4. Yes. The point mutation have an effect on the outcome compared to the normal sequence.
When there is a change in one base of the gene it results into causing disease such as cancer, sickle cell anemia.
The post mortem interval of a body enclosed in a plastic bag could be best estimated by the insects found in the body, in that case forensic science need to listen to what those little creatures have to say, insects could tell if the body has been moved from the crime scene, how long it´s been in an specific place, and how long it´s been since death until found, every group of insects can tell something different, from worms, arachnids to flyes, each one of them has a time to get into the body, so it could tell you for how long it´s been dead.
"Rainwater can replace or replenish freshwater sources" and "precipitation, such as rainwater, is a source of freshwater on Earth" statements describe freshwater sources
<u>Explanation:</u>
Rainwater a source of pure distilled water, evaporated by the sun. When it falls it comes in contact of air and land. when ground soaks the water it becomes mineral water. And it is safe for drinking.
All the freshwater sources are result of precipitation from the earth surface,in various form i.e rain,mist,snow. Freshwater falling as rain have materials dissolved from atmosphere in it,sea and the land over which the clouds has travelled.
Answer: Xiao can use these structures to create a similarity matrix that enables to differentiate between synapomorphies and homoplasies .
Explanation: A synapomorphy is a trait that has been inherited from the same ancestor, this trait enables to establish a relation of homology between two or more species; while a homoplasy is an analog structure that doesn't have homology.
