Answer:
33
Explanation:
because proton number is always equal to atomic number
Answer:
<em><u>In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll</u></em>
Answer:
Four daughter cells are produced each with 40 chromosomes. The daughter cells would exhibit genetic variations and would not be genetically identical to each other.
Explanation:
Meiosis is a cell division that forms four daughter cells from one parent cell as two sequential division meiosis I and meiosis II do not include any DNA replication between them. Crossing over during prophase-I of meiosis-I includes the exchange of genetic segments and occurs between the homologous chromosomes. It produces new gene combinations in the daughter cells which were otherwise not present in the parent cell.
Since there is no DNA replication between meiosis I and meiosis II, the daughter cells have half the number of the chromosomes compared to the parent cell. This occurs as homologous chromosomes move towards the opposite pole during anaphase I.
Therefore, a parent cell with 80 chromosomes will make a total of 4 daughter cells by meiosis. Each daughter cell would have 40 chromosomes. These daughter cells would have some new gene combinations and would be genetically dissimilar among themselves.
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.