<em>G1, S and G2 phases are all cumulatively referred to as interphase involving the growth of a cell and the replication of its DNA. Initially in G1 phase, the cell grows physically and increases the volume of both protein and organelles. In S phase, the cell copies its DNA to produce two sister chromatids and replicates its nucleosomes. Finally, G2 phase involves further cell growth and organisation of cellular contents. The S phase of a cell cycle occurs during interphase, before mitosis or meiosis, and is responsible for the synthesis or replication of DNA. In this way, the genetic material of a cell is doubled before it enters mitosis or meiosis, allowing there to be enough DNA to be split into daughter cells. The S phase only begins when the cell has passed the G1 checkpoint and has grown enough to contain double the DNA. S phase is halted by a protein called p16 until this happens.</em>
The answer is : randomization was not used in sample selection. The major difference between experimental and quasi-experimental designs is lack of randomization in sampling selection.
Answer:
b. a semi-permeable double layer of phospholipids that have hydrophilic heads and hydrophobic tails
Explanation:
B is correct as the cell membrane is selectively semi-permeable. It is selectively semi-permeable because this quality allows it to control what can and can't enter the cell, and how it does so.
The cell membrane also has a phospholipid bi-layer comprised of a double layer of phospholipids which have hydrophilic head and hydrophobic tails. This is because the heads are made of phosphate and are polar and are therefore attracted to water (hydrophilic), while the tails are made of lipids (i.e. fats, oils) which do not mix with water and are therefore hydrophobic.
The properties of each phospholipid is also why they form the double layer structure, the hydrophilic heads naturally face outwards into the water and protect the hydrophobic tails on the inside.
Hope this helped!
The sun is considered a giant star so C)
Answer:
Theoretical yield of tungsten produced = 35.6836915592 ≈ 35. 68 g
Explanation:
The chemical equation can be expressed as follows;
WO3 (s) + 3H2(g) → W(s) + 3 H20(g)
Note that the equation is already balanced.
Molecular Mass of WO3= 183.84 + 15.999 × 3 = 183.84 + 47.997 = 231.837 g
From the equation 1 mole of WO3 reacts with 3 mole of hydrogen molecule.
Molecular mass of tungsten(W) = 183.84 g
1 mole of tungsten was produced from the chemical equation.
WO3 (s) + 3H2(g) → W(s) + 3 H20(g)
From the equation,
231. 837 g of WO3 produces 183.84 g of tungsten
45.0 g of WO3 will produce ?
grams of tungsten produced = 183.84 × 45 /231.837
grams of tungsten produced = 8272.8
/231.837
Theoretical yield of tungsten produced = 35.6836915592 ≈ 35. 68 g
