Answer:
Cycads /ˈsaɪkædz/ are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, therefore the individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow very slowly[3] and live very long, with some specimens known to be as much as 1,000 years old.[citation needed] Because of their superficial resemblance, they are sometimes mistaken for palms or ferns, but they are not closely related to either group.
Cycads are gymnosperms (naked seeded), meaning their unfertilized seeds are open to the air to be directly fertilized by pollination, as contrasted with angiosperms, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators, usually a specific species of beetle. Both male and female cycads bear cones (strobili), somewhat similar to conifer cones.
Cycads have been reported to fix nitrogen in association with various cyanobacteria living in the roots (the "coralloid" roots).[4] These photosynthetic bacteria produce a neurotoxin called BMAA that is found in the seeds of cycads. This neurotoxin may enter a human food chain as the cycad seeds may be eaten directly as a source of flour by humans or by wild or feral animals such as bats, and humans may eat these animals. It is hypothesized that this is a source of some neurological diseases in humans.[5][6]
Cycads all over the world are in decline, with four species on the brink of extinction and seven species having fewer than 100 plants left in the wild.[7] The plant has a very long fossil history, with evidence that they existed in greater abundance and in greater diversity before the Jurassic and late Triassic mass extinction events.
Explanation:
~Dr.Smiley~
(Jane)
The Human Genome Project. The project was a international scientific research project with the goal determining the sequence of nucleotide base pairs that make up human DNA.
Answer:
2 new cells
Explanation:
mitosis creates new cells
Answer:
A clonagem é a obtenção de duas células idênticas com o mesmo código genético que o produto da reprodução assexuada.
Nos mamíferos, a clonagem ocorre através de células somáticas, onde há um núcleo doador e um oócito que se unem por meio de um choque elétrico, formando o embrião que resultará em um ser vivo clonado, um exemplo de essa era Dolly, a ovelha.
Explanation:
Na clonagem de mamíferos, o embrião é responsável por ter caracteres da ovelha doadora, ou seja, será a imitação do código genético desse animal que empresta a célula doadora ao úbere.
Answer:
B
Explanation:
It plays an important role in how the body uses carbohydrates and fats. It is also needed for the body to make protein for the growth, maintenance, and repair of cells and tissues. Phosphorus also helps the body make ATP, a molecule the body uses to store energy. Phosphorus works with the B vitamins.
