Answer:
These strands are clones, however, due to their low genetic variability, the population becomes susceptible to diseases taking place in plants. Pando comprises grove of about 47000 trunks, these all are genetically similar that develops from a solitary underground species, Quaking aspen tree. Pando is an extremely large clone.
However, for the past some years, scientists are worried about Pando's health. For the past thousands of years, Pando was living in fine tune with the native wildlife population, but for the past some years, a shift in balance is noticed. As in the absence of the development of novel stems, nothing will be able to substitute the natural withering of the older ones, if this goes on, the death of Pando will take place.
Answer:The correct answer is " a"
LDL contain protein,triglycerides,phospholipid and cholesterol.
Explanation:
Low density lipoprotein,or LDL,are complex aggregates of lipids and protein.Their function is to transport lipids (fats) around the body,in the bloodstream,and to the cells where its required.Apart from this,it also carries triglycerides,phospholipids and fat soluble vitamins.
Lipoprotein is composed of a hydrophobic core that is made up of polyunsaturated fatty acids and cholesterol molecules,along with a lipid membrane that contains protein called apolipoproteins.
There are 4 major classes of lipoprotein:
•chylomicrons
•very low density lipoprotein(VLDL)
•high density lipoprotein (HDL)
•low density lipoprotein(LDL)
Answer: The bacteria transformed with this particular plasmid will form white colonies on the plates containing ampicillin and Xgal.
Explanation: The lacZ gene produces an enzyme called β-galactosidase which is responsible for the breakdown of lactose into glucose and galactose. The lacZ gene is one of the three genes (the other two being lacA and lacY) of the lac operon which is responsible for the transport and mechanism of lactose in E. coli and many other bacteria.
In recombinant DNA technology, when a plasmid is to be used to transform a host cell, such markers are used to help screen the transformed cells from the ones that have not taken up the plasmid. Xgal present in the plates is an artificial substrate which is hydrolyzed by
β-galactosidase into 5-bromo-4-chloro-indoxyl which will dimerize and oxidise into 5,5'-dibromo-4,4'dichloro-indigo. This is a blue pigment which will give blue color to the bacterial cells. Introducing a DNA fragment in this lacZ gene will make it non-functional so it will not be able to produce the enzyme.
Therefore, when a bacterial cell is transformed with a plasmid containing ampicillin resistance gene and a DNA fragment introduced in the lacZ gene and then grown on plates containing ampicillin and Xgal, white colored colonies will appear. The white colonies will show the bacterial cells that have successfully taken up the plasmid with the DNA fragment incorporated in the lacZ gene as this will render the gene non-functional and will not produce β-galactosidase which will breakdown Xgal to give blue colonies. Since the plates contain ampicillin, only the bacterial cells that have been successfully transformed with the plasmid ( the ones that have the DNA fragment and the ones without it) will grow as the ampicillin resistance will give them resistance against ampicillin in the plates. The bacterial cells that have not taken up the plasmid will not be resistant to ampicillin and will not form colonies on the plate.
This is called blue-white screening which is used to identify successfully transformed host cells. A picture of this is given in the attachment, taken from the following website:
https://www.mun.ca/biology/scarr/Blue_&_White_Colonies.html
Answer:
Coprolites are the type of fossils which can tell the scientist what dinosaurs ate.
Explanation:
A Coprolites is fossilized faeces.They are classified as trace fossils as opposed to body fossils as they give evidence for the animal's behaviour rather than morphology.This name is derived from Greek words.They were first described by William Buckland in 1829.
D
Only eukaryotic cells have membrane bound organelles. Prokaryotes organelles just float in the cytoplasm.