Explanation:
1) The enzyme helicase catalyses the unwinding of the two DNA strands by disrupting the hydrogen bonds between complementary base pairs.
2) Single-stranded binding proteins attach to the DNA strands to stabilise them and prevent them from joining back together.
3) The enzyme primase catalyses the addition of a short primer consisting of RNA nulceotides to the DNA strand. This serves as an 'anchor' DNA polymerase to initiate replication.
4) The enzyme DNA polymerase synthesizes a new DNA strand by incorporating DNA nucleotides complementary to the existing strand. DNA polymerase activity only occurs in the 5' ---> 3' direction.
5) The enzyme ligase catalyses the formation of hydrogen bonds between the two new pairs of DNA strands, and seals any breakages in the sugar-phosphate backbone.
Answer:
Unlike typical mammalian red blood cells, those from amphibians, such as frogs, contain a DNA-bearing nucleus that is visible in the center of the cell. The circulatory system of amphibians is rather unusual, their hearts having three chambers, two atria, and a single ventricle.
NegativePositive
Positive
The design of the amphibian circulatory system is curious because blood accumulates oxygen in the lungs and is then returned to the heart before being pumped into the rest of the circulatory system. Therefore, a mixing between oxygenated and deoxygenated blood occurs as blood returning to the heart from the lungs is mixed with incoming blood from the body. Frogs handle this situation by having a very slow metabolism and by absorbing some oxygen through their skin. In addition, the ventricle does have some directional control over the distribution of the blood.
Negative
The presence of a nucleus in amphibian red blood cells allows researchers easy access to large quantities of amphibian DNA. Frog blood has both a solid and a liquid portion. The liquid plasma carries solid elements such as red and white blood cells. Blood can be collected from frogs and the red blood cells isolated by centrifugation. After removal of the residual plasma, purified cells can be treated with specific enzymes and detergents to digest the cellular envelope and release DNA from its protein complex. The DNA is then useful for scientific studies and experiments.
Featured in: Phase Contrast
Explanation:
<span>The percentage of energy provided by fat when the body at rest is around 60%. The remainder of the energy provided to the body is from other nutrient sources, proteins and carbohydrates. The body uses these calories at rest for regular functions- respiration and other normal bodily processes.</span>
Answer:
Punta kana iintayin kita hahaha
Answer:
A sensory neuron.
Explanation:
The nervous system can be divided in two systems: the central nervous system and the peripheral nervous system. The central nervous system (CNS) is composed by the brain and the spinal cord. The peripheral nervous system (PNS) consists of the nerves and ganglia. Neurons are specialized cells that form the basic functional unit of the nervous system. There are three types of neurons: sensory, motor and interneurons. The sensory neurons are in charge of bringing signals into the CNS, and the motor neurons are in charge of carrying signals out of the CNS. The interneurons act as intermediaries, passing information between two neurons.
As the name implies, sensory neurons are activated by the senses, for example: sound, visible light, physical contact (heat and cold), chemical signals (smell and taste). The loss of sensation in one hand would be the result of a damaged sensory neuron.
