Answer:
They have helical thickening of lignin in their walls to prevent collapse
Explanation:
the primary function of Xylem and its conducting vessels tracheids is to provide support and tranport water and minerals in plants.
Xylem vessels have layers of dead materials in the walls called LIGNIN. Lignin is a polymer; a very strong, hard materials that stop water passage through it,because it contains dead cells,
Therefore the presence of deposit of these strong impermeable, ligified walls in its walls prevent its collapse during mass flow of water of transpiration pull.
Answer:
a, b, d y e
Explanation:
We can define thermogenesis as the method of production of lime or temperature that a living body generates, in biology it is studied that this does not occur in all animals, but is seen in so-called warm blood and some plants, there are three types of processes identified in animals:
NEAT: defined as thermogenesis that occurs without the presence of physical activity
DIT: defined as the thermogenesis that occurs with physical activity
EAT: defined as the thermogenesis that occurs with the consumption of food or diet
Thermogenesis under the thermogenin protein found in brown adipose tissue produces a disengagement of protons within the mitochondria, prevents ATP synthesis and is capable of inducing temperature with the flow of protons, it also intervenes by increasing glycolysis, lipogenesis and gluconeogenesis with which its final result in these processes is the production of energy. The effect of the sympathetic nervous system and thyroid hormones that can balance heat production without generating abnormal movements such as tremor is also recognized.
Thus we deduce that:
electron transport allows heat flow without causing tremors
Thermogenin is involved in allowing protons to enter the mitochondria and the ATP production process is carried out.
hydrolysis of fatty acids occurs in the presence of norepinephrine
in brown adipocytes ATP synthase can be avoided
