1. Explain why neither cyclins nor kinases alone can cause a cell to progress through the cell cycle.
As cyclin accumulates, it activates their kinases that turn on the pathway to mitotic spindle formation, and so on.
2. How do controls of the cell cycle protect multi-cellular organisms from accumulating large numbers of damaged or defective cells?
The checkpoint control is responsible for multi-cellular organisms for not accumulating large numbers of damaged or defective cells. Checkpoint controls consist of proteins that detect mistakes and damage and quickly halt the cell cycle until repairs are made. When this occurs, the cell is said to be in cell-cycle <span>arrest.
</span>3. What is the difference between a cancerous tumor and metastasis?
Cancer is cause by mutations in the genes that encode these proteins can lead to uncontrolled growth. Cancer is when there is uncontrolled cell growth and reproduction. Metastasis is caused by tumors when they grow and interfere with the surrounding tissue or cells and break off and spread around the body. Cancerous tumors cause metastasis, and tumors are caused by mutations in genes that lead to uncontrolled growth.
4. What are the functions of tumor-suppressor genes and protoncogenes in noncancerous cells?
The genes that encode the checkpoint proteins are called tumor suppressors because they suppress the development of cells into tumors. If mutations inactivate these genes, the cell-cycle break is removed with or without a signal from the outside. Proto-oncogene’s are involved in promoting cell division, mutations can cause them to become oncogenes, or cancer genes which stimulate cells to leave G0 and divide whether or not it is a signal.
It's because taking them regularly until the prescription is complete helps ensure that all of the illness-causing bacteria are killed or prevented from multiplying
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.
<span>A tropism is a movement of an organism toward or away from a stimulus. A positive tropism is when the organism moves toward the stimuli. A negative tropism is when the organism moves away from the stimuli. So, your answer will be negative tropism, since the stem is growing up and out of the soil, AWAY from gravity.</span>
Answer:
Larger habitats support populations with higher carrying capacities. Higher quality habitats support populations with higher carrying capacities. There is no difference in population growth rate between large and small habitats. Some major threats to biodiversity are: Habitat destruction/Deforestation, Introduced and invasive species, Genetic pollution, Over exploitation, Hybridization, Climate change, Diseases, Human overpopulation. If abiotic or biotic factors change, the carrying capacity changes as well. Natural disasters can destroy resources in an ecosystem. If resources are destroyed, the ecosystem will not be able to support a large population. This causes the carrying capacity to decrease.
Carrying capacity could be reduced if each individual within the species consumed less from the environment. Think about humans: if every human needs a four car garage and a large house, the planet can sustain fewer humans than if each human lived in a studio apartment and traveled using a bicycle. It would take 1.75 Earths to sustain our current population. If current trends continue, we will reach 3 Earths by the year 2050. It is beyond dispute that the modern industrial world has been able to temporarily expand Earth's carrying capacity for our species. As Nordhaus points out, population has grown dramatically (from less than a billion in 1800 to 7.6 billion today), and so has per capita consumption. Historically, habitat and land use change have had the biggest impact on biodiversity in all ecosystems, but climate change and pollution are projected to increasingly affect all aspects of biodiversity. Sustainable agriculture practices support integrating biodiversity in various ways including in terms of diversity of crops, traditional agriculture techniques to control pests and increase productivity as well as ensuring that farmed land is made up of a diverse mix of grazing land, crop land, orchards, wetlands and more.
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