Answer: the membrane channel
Explanation:
In passive diffusion, the small water molecules can move across the phospholipid bilayer seen in blue. This layer acts as a semi-permeable or selectively permeable membrane; its hydrophilic heads are attracted to water (seen facing outwards) while its water-repellent hydrophobic tails face towards each other- allowing molecules of water to diffuse across the membrane along the concentration gradient.
Thus the water will move from an area of high concentration to an area of low concentration, until the system reaches a steady state called equilibrium- after this, there will be no net movement of water. Similarly via osmosis, the water passes through the membrane due to the difference in osmotic pressure on either side of the phospholipid bilayer this means that the water moves from regions of high osmotic pressure/concentration to regions of low pressure/ concentration to a steady state.
The dialysis tubing mimics a semi permeable membrane; it only allows water and small molecules of iodine to cross into the bag containing starch. The tubing is impermeable to starch; these large molecules require the aid of protein omplexes called membrane channels, in order to move across the membrane and against the concentration gradient.
The correct answer is B. Meet current and future resource needs.
Explanation:
Sustainability implies an equilibrium between the natural resources available and the resources humanity requires. This equilibrium is reached when the natural resources extracted from nature are enough to satisfy human needs without depleting the resources or causing these are not available in the future. In this context, the goal of sustainable development is to make sure now and in the future resource needs are meet (option B). Moreover, this is possible through actions such as recycling, reducing deforestation, creating environment-friendly technologies, among others that reduce the depletion of resources or preserve the environment.
He should eat fruits and veggis
The term ‘Crossing over’ was used by Morgan and Cattell. It is a process in which there is exchange of chromosome segments between non-sister chromatids of a homologous chromosomes. It occurs during pachytene stage of prophase I of meiosis cell division.
Significance of crossing over:
- Crossing over provides genetic variation in all sexually reproducing organisms.
- It creates new combination of genes or genetic recombination and produces hybrids.