Answer:
1. Weaker
2. Continuous
Explanation:
A tumor suppressor gene codes for retinoblastoma protein (pRb). The retinoblastoma protein binds to transcription factor E2F when DNA damage is detected. The E2F bound to pRb can not stimulate expression of genes that code for proteins required during the process of DNA synthesis. The cell can not enter the S phase.
On the other hand, when the retinoblastoma protein is phosphorylated by cyclin E-CDK2, E2F transcription factor is free to stimulate the expression of genes required for DNA synthesis and the cell proceeds from G1 to S phase.
When the mutated retinoblastoma gene code for a protein that serves as phosphorylated protein, it will not be able to bind strongly with E2F and there would be continuous expression of genes required for S phase.
Answer:
Xylem cells have no cytoplasm or end walls, meaning they form a tube through which water can pass freely to allow water transport. Lignin strengthens the cell walls, helping to support the plant.
Nuts indeed are a good source of vitamin E. This is true. However, when talking about nuts we have to consider that not all nuts have the same nutritional information nor do all of them have plenty of vitamin E. While we can say this for most, it is necessary to be wary of making such statements.
