Prokaryotic bacteria are surrounded by a cell membrane that contains the transport proteins to regulate the entry and exit of materials through the cell, the cell wall to help maintain cell shape and structure, and the capsule, which aids against drying out and protects bacteria from a host's immune system.
<h3><u>Explanation:</u></h3>
Bacteria are the prokaryotic organisms that are found in every part of Earth. These organisms do have an interesting ultrastructure. The coverings of the bacteria are three in layer. They are
A. The outer capsule.
B. The middle cell wall.
C. The inner cell membrane.
The capsule is the outermost covering of bacteria that is formed of different slimy materials. These materials contains hygroscopic substances which can absorb water from the surroundings even when the water concentration in outside is very very low. This layer of protection outside bacteria help them to protect themselves against drying out at dry conditions.
The middle cell wall is formed of polymers of N acetyl glucosamine and N acetyl muramic acid. This layer is chitin in nature and is strong enough to maintain the shape and size of bacteria irrespective of outer conditions.
The innermost layer of bacteria is cell membrane which is formed of proteins and lipids bilayer and this cell membrane contains different transport for proteins which help in transport of different substances like water and nutrients inside the cell by means of active transport or passive diffusion.
The answer is C. When a vacuole is filled with water, turgor pressure exist, it can keep the cells turgid and therfore to make the plant stay upright and prevent it from wilting.
Answer:
c) melatonin
Explanation:
Melatonin its a hormone formed by the pineal gland, which regulates an individual wake cycles and sleep. Jetlag alters the hormone function leading to an alteration with the body clock of the persom.
Jetlag is a sleep disorder common to those who travel swiftly over several time zones. It is not a permanent sleep disorder. Its due to the body's internal clock lacking sync with cues generated in a different time zone, Cues may be due to light exposure and how often the person eats.
A basic factor on ones internal clock is sunlight. It controls the regulation of melatonin which aid in synchronizing cells in the body.
Specific cells of the tissue at retina moves the light signals the thypothalamus.
At night, the hypothalamus signal to the pineal gland to produce melatonin. At daylight hours, the reverse is the case.
Answer:
The correct answer is - 1. true, 2. true, 3. false, and 4. true.
Explanation:
1. Rod cells are the photoreceptors present in the retina that are hyperpolarized not depolarized in dark due to sodium ions efflux.
2. Depolarisation of the bipolar cell of the retina by glutamate release by rods and cones.
3. The adaption according to the light is known as a light adaptation which takes place due to a large part of photochemical in both rods and cones which is reduced to retinal and opsins.
4. when the light reaction takes place retinal converted to opsin