Answer:
The answer to this question is B
The given question says that a student has constructed a model of cellular transport using fences and several gates.
This model can be used to demonstrate the cellular transport.
The gates of the fences can be supposed as the protein pumps and the other fence demonstrates the lipid bilayer.
Let’s suppose in the fence, there are many cattles, and outside, there are less cattles, but the student open the gate and bring more cattles inside the fence. In this case, the transport of the cattles is similar to the active transport of the molecules using protein pumps. At cellular level, the energy for the active transport is provided by ATP molecules.
Now, let’s say, the student wants to feed the cattles with some nutrition rich food, which can help in maintaining the health of the cattles. The student fills his car with the cattle food and he enters inside the fence through gates. In this case, the food was not present in the fence, but was abundant in the outside environment, so, the diffusion would occur. But food cannot come self, without help of others, so, the movement is facilitated by the car, as it is done by the carrier proteins. Hence, it is an example of facilitated diffusion.
Around 100,000 years ago there was a second hominine species closely related to modern humans, Homo <span><span>neanderthalensis,</span><span> or commonly called the Neanderthal</span>.</span> Recent studies of neanderthal DNA have shown that there is 3-4% of their genes in modern humans outside of Africa, mostly from Europe, including the ones for adapting to the cold and vitamin D absorption.
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.
