Answer:
a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically
Explanation:
Answer:a species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.
Explanation:
The American Beaver (Castor canadensis) is one example of a keystone species in North America. In any arrangement or community, the “keystone” is considered one of the most vital parts. In a marine ecosystem, or any type of ecosystem, a keystone species is an organism that helps hold the system together.
Select the correct answer.
Jayden is taking a test. He has to write why scientists support the theory that life began near hydrothermal vents in the ocean. Which point should he include in his answer?
A.
Hydrothermal vents were closest to ocean surface, and therefore could receive oxygen.
B.
Oceans were dry and only had water near the hydrothermal vents in the earlier ages.
C.
Even today, all life forms are first born near hydrothermal vents and they later migrate to land.
D.
Fossils of archeabacteria, which are early common ancestors, were found near hydrothermal vents.
Answer:
The answer is; D
Archaebacteria are early life forms on earth. They utilized the process of chemosynthesis to make organic molecules from inorganic molecules and for energy. The word archae means ‘ancient’ life forms. These single-celled organisms evolved around sulfur-rich environments of the hydrothermal vents.
Answer:
D
Explanation:
The zika virus was first identified in Uganda in 1947. The virus is transmitted from person to person by a bite from a mosquito. It is commonly carried by the Aedes mosquito which is prevalent throughout Central Africa. The virus has more recently spread to the Americas (South, Central, and now North) and is expected to spread to Europe. There is a concern that the virus may reach epidemic proportions. Zika virus is related to yellow and dengue fever. Common symptoms are low grade fever and a distinctive skin rash and other symptoms include vomiting, headache, and muscle and/or joint pain. Pregnant women should avoid traveling to areas known to have zika virus present because the virus is known to cause microcephaly and developmental difficulties related to the central nervous system. Based on the paragraph above, class discussions, and other VALID (be careful with your selection of e-materials! CDC – Center for Disease Control is a good place to start) sources of information please answer the following questions.
1. State a reason why the virus has spread to the Americas and likely to spread to Europe.
2. Define the term microcephaly.
3. What bones of the fetal skull would be affected by zika? Specifically, what area of the CNS is not fully developed in microcephalic individuals.
Answer:
1. It is a highly contagious disease transmitted from person to person and thereby it is expected that infected persons carried the virus to America
2. Microcephaly is a serious birth defect where a baby’s head is much smaller than expected.
3. Occipital bone. CNS malformations: ventriculomegaly, parenchymal and periventricular calcifications and cortical migration anomalies
Explanation:
The Zika virus (Flaviviridae) causes a contagious disease and it is transmitted by Aedes mosquitoes, which are also the main vectors of the dengue virus. Microcephaly is a condition where the baby’s brain has not developed properly during pregnancy, and it has been shown that this birth defect is associated with the Zika virus. During 2015 in Brazil, the incidence of infants with microcephaly born from mothers that contracted this disease during pregnancy was higher, thereby suggesting an association between both conditions. Baby health problems associated with Zika infection include microcephaly (skull partially collapsed), joints with limited motion, etc.
What part of the cell determines the type and order of the amino acids that make up a protein?
Answer:
The gene, or sequence of DNA, ultimately determines the unique sequence of amino acids in each peptide chain. A change in nucleotide sequence of the gene's coding region may lead to a different amino acid being added to the growing polypeptide chain, causing a change in protein structure and therefore function.