Answer: Ice cores.
Explanation: Ice cores are commonly studied by scientists to find out what the climate was like decades and centuries ago.
Answer:
Because older cultures of gram-positive bacteria tend to lose their ability to retain crystal-violet in the peptidoglycan of their cell walls and can be confused with gram-negative bacteria.
Explanation:
Gram staining is used to differentiate between two major groups of bacteria. Gram-positive and gram-negative, these bacteria differ in the amount of peptidoglycan in their cell walls. Gram-positive bacteria have a higher amount of peptidoglycan, which absorbs the violet crystal complex used in gram staining, staining them purple/violet. Old cultures of gram-positive bacteria tend to lose the ability to retain the violet crystal and are stained by safranine, staining them red/pink and appear to be gram-negative.
Answer:
There are two types of vesicle transport, endocytosis and exocytosis (illustrated in the Figure below). Both processes are active transport processes, requiring energy. Illustration of the two types of vesicle transport, exocytosis and endocytosis.
Explanation:
So in a simple explanation yes they require energy:)
The right answer is polarity.
In chemistry, polarity is a characteristic describing the distribution of negative and positive charges in a dipole. The polarity of a bond or a molecule is due to the difference in electronegativity between the chemical elements that compose it, the differences in charge that it induces, and to their distribution in space. The more the charges are distributed asymmetrically, the more a bond or molecule will be polar, and conversely, if the charges are distributed in a completely symmetrical manner, it will be apolar, that is to say non-polar.
Polarity and its consequences (van der Waals forces, hydrogen bonding) affect a number of physical characteristics (surface tension, melting point, boiling point, solubility) or chemical (reactivity).
Many very common molecules are polar, such as sucrose, a common form of sugar. The sugars, in general, have many oxygen-hydrogen bonds (hydroxyl group -OH) and are generally very polar. Water is another example of a polar molecule, which allows polar molecules to be generally soluble in water. Two polar substances are very soluble between them as well as between two apolar molecules thanks to Van der Waals interactions.