Advantages and Disadvantages of shopping in Internet

ADVANTAGES: The most important advantage of shopping in internet is you can save a lot of time, because you don’t spend it going to the mall or shops. Besides, shopping in internet is so comfortable, because you can do it in your home or another place connected to internet. Is often believed that shopping in internet is much expensive, but that’s no completely true, usually is cheaper than the shops. An additional advantage is that’s easier find what are you looking for.

DISADVANTAGES: The main disadvantage of shopping in internet is you can’t buy without a credit card. Therefore, you can’t watch how is what you want to buy, because you only see a picture or photo that could be perfectly a fake. Another disadvantage is sometimes, if you live in regions, you must pay delivery.

Task 2: Salmon parents give birth to trout…

Thanks to genetic techniques now is possible to create viable fish sperm and eggs. The researches based in previous works like one made by Goro Yoshizaki and his team in the Tokyo University, in which they show that male salmon could be injected with cells from closely-related trout to produce viable trout sperm and introduce this sperm in a female trout to generate a healthy offspring. Now the researches want also make the mother could be a salmon.

The technique is based in the injection of trout spermatogonias (the early cell in the sperm development) into a salmon embryo. But when this salmon grew up produced trout sperm mixed with salmon sperm which generated hybrids that did not survive. So, the researches made the male salmon embryo sterile (adding to it another chromosome) and then injected into it the trout spermatogonias. Also they injected trout spermatogonias into the female salmon embryo which produced trout eggs. As a result, they produced a healthy trout offspring.

The researchers hope this technique could be used to save endangered fishes and another species.

http://www.nature.com/news/2007/070910/full/070910-11.html