Answer:
This question is incomplete
Explanation:
Introns are non-coding regions of a DNA that removed by RNA splicing prior to translation. Alignment is usually done between sequences to see and understand the identity and similarity between two or more sequences.
A region/base is said to be conserved if there is NO change in any base in that particular region. A multiple sequence alignment (MSA) can be used to align the donor sites of all the introns to see the bases that have not "changed" (and still remained in there exact position) hence conserved across all the donor sites.
NOTE: The donor site of an intron is the 5' end, thus the first five bases in the 5' end are to be used here
Answer:
The correct answer is "5-1-3-2-4".
Explanation:
Internalization of LDL particles into cells, is needed to form the intracellular vesicles known as endosomes. The order of events that allow for this process are:
5) LDL receptors migrate to the cell surface and cluster in clathrin-coated pits. Clathrin acts directing the receptors to the cell membrane region where endosomes are formed.
1) A combination of cholesterol and apolipoprotein binds to LDL receptors and becomes internalized as endocytotic vesicles. Once the receptors are in the proper cell membrane region, cholesterol and apolipoprotein are bound and internalized.
3) Several endocytotic vesicles fuse to form an endosome.
2) The environment of the endosome becomes acidic, which causes the LDL to dissociate from its receptor; additionally, the endosome fuses with a lysosome. LDL should be dissociated from its receptor since it is going to be degraded in the following step.
4) The LDL particle is degraded by the lysosome. This takes place after endocytosis, when LDL particles are transported into lysosomes once they are fused, cleaving the cholesterol esters into cholesterol and fatty acids.
Answer:
diverse proteins embedded in a phospholipid bilayer
Explanation:
According to fluid mosaic model the cell membrane is made of bilayer of phospholipid. Many proteins are embedded in this bi layer. Carbohydrate and cholesterol are also found in different forms. Carbohydrate can either be attached to the embedded protein in which case it is called as glycoprotein or it can be connected to the lipid molecule in layer and called as glycolipid.
Proteins can be found in two forms too. They can either be embedded in the layer i.e. they can penetrate single or both layers. These proteins are called as integral proteins. They can also be present on one side of the membrane and not penetrate the lipid bilayer in which case they are called as peripheral proteins.
Answer: D. Extinctions occur at higher rates during times of ecological stress when populations and species are poorly adapted.
