Answer:
Hibernation is a way animals conserve energy to survive adverse weather conditions or lack of food. It involves physiological changes such as a drop in body temperature and slowed metabolism. Research into the processes involved in hibernation could result in medical benefits for people
Explanation:
Answer:
The correct answer is the letter b. The endosymbiotic event that brought chloroplasts into Eukaryotic cells actually happened after Eukaryotic lineages diverged so many lineages never actually possessed chloroplasts
Explanation:
The plastid is an organelle linked to membarna found in the cells of eukaryotic organisms, which contains pigments used in photosynthesis. Some eukaryotic organisms over time have inherited the ability to photosynthesize from cyanobacteria by secondary endosymbiosis or ingestion, and are able to capture and sequester photosynthetic cells and chloroplasts, this process is known as kleptoplasty.
Más allá del tamaño, las principales diferencias estructurales entre células vegetales y animales están en algunas estructuras adicionales encontradas en las células vegetales. Estas estructuras incluyen: cloroplastos, la pared celular y vacuolas.
Answer:
"As a molecule moves through the plasma membrane it passes through <em>a hydrophilic layer of phospholipid heads then a hydrophobic layer of phospholipid tails and then another hydrophilic layer of phospholipid heads".</em>
Explanation:
Biological membranes are formed by two lipidic layers, proteins, and glucans.
Lipids characterize for being amphipathic molecules, which means that they have both a hydrophilic portion and a hydrophobic portion at the same time. These molecules have a lipidic head that corresponds to a negatively charged phosphate group, which is the polar and hydrophilic portion. They also have two lipidic tails that correspond to the hydrocarbon chains -the apolar and hydrophobic portion- of the fatty acids that esterify glycerol.
Membrane lipids are arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, while their hydrophobic tails are against each other, constituting the internal part of the membrane.
Through this lipidic bilayer, some molecules can move from one side of the cell to the other, which happens because of concentration differences. When this occurs, molecules must pass through the hydrophilic layer of phospholipid heads then through the hydrophobic layer of phospholipid tails and then again through another hydrophilic layer of phospholipid heads.
