<span>b.internal fertilization
</span>Sexual reproduction provides genetic variation because the sperm and egg that are produced contain different combinations of genes than the parent organism. Sexual reproduction involves meiosis which is the process of a cell doubling its DNA, shuffling its genes and then dividing the shuffled DNA among four cells.<span>Each resulting cell, or gamete from meiosis has only half the amount of DNA as the parent cell. So in order to form a new organism, two gametes, sperm and egg, must fuse, further mixing the genes to produce more genetic variation.</span>
Answer:
In normal conditions, introns serve following functions in the body of an organism:
1) They contain genes of miRNA which are known as Mirtrons, reverse transcriptase, endonucleases, transposase etc.
2) It is because of presence of introns that alternative splicing of mRNA is possible. The sex determination in drosophila is based on alternative splicing.
Apart from this, alternative splicing can be useful and beneficial in an unforeseen situation such as an environmental problem which is faced by the organism for the first time.
Explanation:
Alternative splicing is an important mechanism because with the help of alternative splicing different type of proteins can be synthesized from the same pre mRNA transcript. In case suddenly the surrounding environment of an organism is changed and the environmental conditions have become extremely harsh due to which organism's life is at stake, in such situation organism may make a different type of protein through alternative splicing which can help the organism in survival.
Default splicing in Drosophila leads to the development of male off-spring while female off-spring is produced as a result of alternative splicing.
Darwin's book suggested that organisms evolve through natural selection.
Answer:
A c-shaped spine.
Explanation:
The correct answer is - A c-shaped spine.
Reason -
A c-shaped spine is a trait of Quadri-pedal spine not of bipedal spine.
Answer: colostomy
Explanation:
Colostomy is a surgical procedure which is used to remove waste or feces from the body when the body is incapable of expelling out the waste. A stoma is the opening either created surgically or naturally present. It is the opening in the large intestine it allows the removal of the feces out of the body. The feces is drain through the rectum into the pouch of the collection device.