Answer:
All of these choices are correct.
Explanation:
Transposons are the DNA sequences that can move from one location to another in the genome. The transposon genes are also known as jumping genes.
The C value paradox of the transposable elements depends on the different factors. The transposons can increase their number by copy and paste mechanism. The genes can be controlled by the enzyme transposase and their copies may exist at the different site of the chromosome.
Thus, the correct answer is option (D).
Biodiversity provide clean air, fresh water, medicines and food security which is also limit to disease and stabilize the climate.
Biodiversity or biological diversity is defined as the variety and variability of life on Earth as a measure of variation at the genetic, species and ecosystem levels. It is described as the great diversity of life on Earth which can be used to refer to all the species in a particular area or ecosystem. Biodiversity is means to every living thing, including plants, bacteria, animals and humans.
The three levels of biodiversity are as follows:
Thus, the Biodiversity provide clean air, fresh water, medicines and food security which is also limit to disease and stabilize the climate.
Learn more about Biodiversity, here:
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1. Ecological stability
Each species performs a particular function within an ecosystem. They can capture and store energy, produce organic material, decompose organic material, help to cycle water and nutrients throughout the ecosystem, control erosion or pests, fix atmospheric gases, or help regulate climate.
Ecosystems provide support of production and services without which humans could not survive. These include soil fertility, pollinators of plants, predators, decomposition of wastes, purification of the air and water, stabilisation and moderation of the climate, decrease of flooding, drought and other environmental disasters.
Research show that the more diverse an ecosystem the better it can withstand environmental stress and the more productive it is. The loss of a species thus decreases the ability of the system to maintain itself or to recover in case of damage. There are very complex mechanisms underlying these ecological effects.
2. Economic benefits to humans
For all humans, biodiversity is first a resource for daily life. Such 'crop diversity' is also called agrobiodiversity.
Most people see biodiversity as a reservoir of resources to be drawn upon for the manufacture of food, pharmaceutical, and cosmetic products. Thus resource shortages may be related to the erosion of the biodiversity.
Some of the important economic commodities that biodiversity supplies to humankind are:
- FOOD : crops, livestock, forestry, and fish
- MEDICATION: Wild plant species have been used for medicinal purposes since before the beginning of recorded history. For example, quinine (Used to treat malaria) comes from the bark of the Amazonian tree Cinchona tree; digitalis from the Foxglove plant (chronic heart trouble), and morphine from the Poppy plant (pain relief).
According the National Cancer Institute of the USA, over 70 % of the promising anti-cancer drugs come from plants in the tropical rainforests. Animal may also play a role, in particular in research. It is estimated that of the 250,000 known plant species, only 5,000 have been researched for possible medical applications.
- INDUSTRY: fibres for clothing, wood for shelter and warmth. Biodiversity may be a source of energy (such as biomass). Other industrial products are oils, lubricants, perfumes, fragrances, dyes, paper, waxes, rubber, latexes, resins, poisons and cork can all be derived from various plant species. Supplies from animal origin are wool, silk, fur, leather, lubricants, waxes. Animals may also be used as a mode of transportation.
- TOURISM & RECREATION: biodiversity is a source of economical wealth for many areas, such as many parks and forests, where wild nature and animals are a source of beauty and joy for many people. Ecotourism in particular, is a growing outdoor recreational activity.
3. Ethical reasons
The role of biodiversity is to be a mirror of our relationships with the other living species, an ethical view with rights, duties, and education. If humans consider species have a right to exist, they cannot cause voluntarily their extinction. Besides, biodiversity is also part of many cultures’ spiritual heritage.
Compared to fingerprint evidence alone, DNA was far more likely to lead to suspects and result in arrests. In crime scenes where biological evidence was collected and tested, DNA evidence was five times more likely than fingerprints to yield a suspect and nine times more likely to lead to an arrest.
An action potential in a muscle cell is initiated by acetylcholine, which binds to receptors on the muscle cell membrane, causing depolarization. This triggers voltage-gated sodium channels to open, allowing sodium influx into the cell, which propagates the action potential. The action potential then leads to muscle contraction.
An action potential on a muscle cell is initiated through a complex sequence of events. First, a neurotransmitter called acetylcholine (ACh) is released from the motor neuron and binds to receptors on the muscle cell membrane or sarcolemma. This binding opens up a channel in the ACh receptor, allowing positively charged sodium ions to enter the muscle fiber.
This ion movement causes the muscle fiber to depolarize, or become less negative, changing the membrane potential. As the membrane depolarizes, another set of ion channels, the voltage-gated sodium channels, are activated and trigger an influx of more sodium ions into the muscle fiber.
This flooding of sodium ions propagates an action potential, or electrical signal, across the entire muscle cell membrane. This action potential then interacts with the sarcoplasmic reticulum to release calcium ions, leading to muscle contraction.
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