Answer:
They remain in an environment,even as more competitive species arrive
Explanation:
Pioneer species, in ecological succession, are the first set of organisms to colonize a bare area of land or a disturbed area of land. Pioneer species include lichens, grasses, fungi etc.
Pioneer species have unique characteristics that distinguishes them from every other species of organism. These include:
- They facilitate environmental change, making an environment more habitable for other species.
- They tolerate a wide range of environmental conditions.
- They are capable of colonizing a barren environment, as in primary succession.
However, pioneer species do not remain in an environment, even as more competitive species arrive. They rather give way for new species to emerge and dominate.
<h3>answer:</h3>
The definition of a herd is a big group of animals or people who share the same characteristics. An example of a herd is a group of cattle, sheep or elephants who all live and travel together.
Answer:
they use to live
Explanation:
As they breath out carbon dioxide the plants take in the carbon dioxide and make air with it. Animals also use air to do their day to day things like eat.
<u>Answer;</u>
C) organic matter; rocks.
The uppermost horizon, horizon O, in this profile is composed mostly of <u>organic matter</u>, while the lower horizon, horizon C, is composed mostly of <u>rocks.</u>
<u>Explanation;</u>
-Soil contains the following major horizons, that is A B and C. Some soils may have horizon O, which may be thin or thick or even lack in some soils. This O horizon is found at the surface of many soils and normally contains organic materials at various decomposition stages. these are materials such as plants, leaves and bugs.
-C horizon is the layer that is below the B horizon. It contains larger weathered fragments or broken up-bedrock.
Answer:
All of these choices are correct.
Explanation:
Cell cycle is the process of growth and division of cell. It comprises of interphase and mitosis. In interphase the cell grows, replicates its genomic content and prepares itself for division. In mitosis the division occurs.
Cell cycle is controlled by a group of kinases called as Cyclin dependent Kinases (CDKs). They act by phosphorylating their substrates. They are of various types like Cdk1, Cdk2, Cdk4 etc. They become active when they bind to a regulatory protein called cyclin. They are also of various types like Cyclin A, Cyclin B, Cyclin C etc. Level of cyclin and corresponding CDK increases and decreases according to the stage of cell cycle. For example in S phase of cell cycle concentration of cyclin A and E shoots up. CDK2 is able to bind to these cyclin molecules and hence it becomes active.
Cell cycle has major checkpoints where the condition of cell is analysed before it proceeds to the next stage of cycle. If any abnormality is detected, repair mechanism is activated or the cell is killed. Checkpoints do not allow cell cycle to proceed in damaged cells.
p53 is a tumor suppressor protein which can halt cell cycle when it detects some abnormality in cell. It usually acts in G1/S checkpoint (before the DNA replication starts in cell) and G2/M checkpoint (before the cell division begins). Hence, all of the above statements are true.
