Answer:
there are 6 lava of silkworm moult.
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.
Mechanisms of evolution correspond to violations of different Hardy-Weinberg assumptions. They are: mutation, non-random mating, gene flow, finite population size (genetic drift), and natural selection.
<h2>
Vascular and Nonvascular Plants </h2>
Explanation:
Kingdom Plantae on the basis of vasculature is divided into two groups-vascular and non-vascular plants
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- <u>Vascular plants </u>or tracheophytes have a proper tissue-level organization and true shoot and root structures like leaves, stem, flowers, root etc
- The tissue system or vasculature of vascular plants compromises of vascular tissues like tubular vessels – xylem and phloem
- The xylem transports nutrients to various parts of the body from the leaves.
- Phloem conducts water and other nutrients from the roots to various parts of the plant
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- These are flowering plants that include the phanerogams – angiosperms and gymnosperms and bears flowers and fruits like the cedars, pine, clubmosses, lilies, sunflower etc.
- Dicots are with tubular vasculature.
- Non-vascular plants or bryophytes with an absence of proper tissue-level organization and true shoot or root systems
- <u>Nonvascular plants</u> are small. Their transport mechanism is poor due to lack of vascular tissues
- These plants are lack proper shoot or root system.
- It includes mosses, hornworts etc.
- Monocots are plants with scattered tube-like vessels
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