Answer:
PFFT this might help? sorry if not mate
Explanation:
Cell cycle checkpoint controls play a major role in preventing the development of cancer [see Sherr, 1994, for a more detailed discussion]. Major checkpoints occur at the G1 to S phase transition and at the G2 to M phase transitions. Cancer is a genetic disease that arises from defects in growth-promoting oncogenes and growth-suppressing tumor suppressor genes. The p53 tumor suppressor protein plays a role in both the G1/S phase and G2/M phase checkpoints. The mechanism for this activity at the G1/S phase checkpoint is well understood, but its mechanism of action at the G2/M phase checkpoint remains to be elucidated. The p53 protein is thought to prevent chromosomal replication specifically during the cell cycle if DNA damage is present. In addition, p53 can induce a type of programmed cell death, or apoptosis, under certain circumstances. The general goal of p53 appears to be the prevention of cell propagation if mutations are present. The p53 protein acts as a transcription factor by binding to certain specific genes and regulating their expression. One of these, WAF1 or Cip1, is activated by p53 and is an essential downstream mediator of p53-dependent G1/S phase checkpoint control. The function of p53 can be suppressed by another gene, MDM2, which is overexpressed in certain tumorigenic mouse cells and binds to p53 protein, thus inhibiting its transcriptional activation function. Other cellular proteins have been found to bind to p53, but the significance of the associations is not completely understood in all cases. The large number of human cancers in which the p53 gene is altered makes this gene a good candidate for cancer screening approaches.
When focusing a specimen you should always start with the SCANNING objective. Scanning objective is used to put the object you want to examine in focus. After proper focusing on the object, you can now switch to power objective.
Answer:
C. phylum
Explanation:
According to the Carolus LInnaeus (1707-1778), He identified the system of classification of organisms into seven taxa which includes: Kingdom, Phylum, Class, Order, Family, Genus, species.
Kingdom:
The highest category into which organisms are classified and in which the whole of nature could fit.
Phylum:
A category used in the classification that consists of one or several similar or closely related classes. It is known as PHYLUM in classification of animal species and DIVISION in plant species.
Class:
One or several similar or closely related orders. Similar classes are said to be grouped into PHYLUM.
Order:
One or several similar or closely related families. Similar orders form a
CLASS.
Family:
One or several similar or closely related genera. Similar families are grouped into an ORDER.
Genus (pl. genera):
A number of similar or closely related species. Similar genera are grouped into a FAMILY.
Species:
A group of similar individuals that can breed and produce fertile offspring.
Similar and related species are grouped into a GENUS.
Answer: The Moon's gravity is mostly responsible for our tides, but the Sun also plays a role (Figure 14.13). The Sun is much larger than our Moon. ... This happens because the Moon's high tide occurs in the same place as the Sun's low tide and the Moon's low tide is added to by the Sun's high tide.
Explanation:
Answer:
The correct answer would be - complex eyes evolved in the gradual steps, each of which was fully functional and adaptive in improving visual acuity.
Explanation:
The natural selection of the complex traits such as the vertebrate eye (complex eye) are seems to be problematic, many biologist think that the complex eyes evolution is take place in gradual steps and each step of this evolution was adaptive and functional in improving the visual acuity.
The steps that were involved are like light sensitivity patch, a deepening hole or pit that help in sharp vision and many other random evolution steps.
Thus, the correct answer is- complex eyes evolved in the gradual steps, each step of this evolution was fully functional and adaptive that helps in improving visual acuity.
