Answer:
the rate of change of velocity with time is called acceleration.
it can also be defined as the increase in velocity per second.
The S.I. unit of acceleration is meter per second square or ms−2.
formula; a = Δv / Δt
where a is acceleration,
Δv is the change in velocity,
and Δt is the amount of time it took for that change to occur.
Type 1 diabetes occurs when your immune system, the body's system for fighting infection, attacks and destroys the insulin-producing beta cells of the pancreas. Scientists think type 1 diabetes is caused by genes and environmental factors, such as viruses, that might trigger the disease.
Answer/Explanation:
Types of reproductive isolation include: temporal, ecological, mechanical, and behavioural.
A snail with a flat disc-like shell will not be able to mate with a snail having a conical shell - this is an example of mechanical isolation, where the animals are physically unable to mate due to incompatible body shapes and sizes.
The reproductive organs of male bush babies do not match with the reproductive organs of females of other bush baby species. - this is another example of mechanical isolation, as the sexual organs will physically not allow reproduction between these species
The mating call of a cricket is not recognized by a cricket of other species - this is an example of behavioural isolation, which results from incompatible mating rituals. I.e. the animals do not respond to each others mating behaviours
The signals sent by a male firefly are not recognized by the female firefly of other species. - this is also an example of behavioural isolation.
Temporal isolation is where species cannot interact because they do not have the same mating seasons or are not active at the same type of day. ?Ecological isolation occurs when two species do not come into physical contact to one another because they access different areas of the habitat. E.g. mating zones, food sources or nesting sites.
The "scissors" of the molecular biology are: DNA Restriction enzymes.
A restriction enzyme is a protein capable of cleaving a DNA fragment at a characteristic nucleotide sequence called a restriction site. Each restriction enzyme thus recognizes a specific site. Several hundred restriction enzymes are currently known.
Naturally present in a large number of species of bacteria, these enzymes have become important tools in genetic engineering.
The "glue" of the molecular biology are: DNA ligase
In molecular biology, DNA ligases are ligase-class enzymes that catalyze the formation of a phosphodiester bond between two segments of DNA. DNA ligases are involved in several essential cellular processes of DNA metabolism: in DNA replication, suture of Okazaki fragments, and in DNA repair and homologous recombination.
The use of these tools in molecular biology: Cloning
Molecular cloning is one of the bases of genetic engineering. It consists of inserting a DNA fragment (called insert) in an appropriate vector such as a plasmid for example. The new plasmid thus created will then be introduced into a host cell, generally the Escherichia coli bacterium. This will then be selected and multiplied to obtain a large amount of the plasmid of interest. Cloning a gene involves inserting it into a plasmid. A clone will be the bacterial transformant that contains this particular plasmid. In this case we speak of clone because all the individuals of the bacterial colony are genetically identical. Molecular cloning is thus different from reproductive cloning (creating an individual genetically identical to another but of a different age) or therapeutic cloning (making tissues from stem cells to perform transplants compatible with the recipient).
Molecular cloning requires restriction enzymes capable of cleaving the DNA, and DNA ligase capable of re-gluing the DNA fragments. Ligase was isolated for the first time from T4 bacteriophage. This enzyme is involved in the repair and replication of DNA. It can bind DNA fragments with compatible sticky ends. At higher concentration, this enzyme is also able to bind two ends of DNA as shown here. T4 DNA ligase works using ATP and Mg ++. It has an activity optimum of 16 ° C, but remains active at room temperature.
Answer:
Cell Membrane---Semi-permeable
Explanation:
All cells have cell membranes, regardless of the type, and they are all semi-permeable, or selectively permeable, which means they can regulate what enters and leaves the cell.
