The right options are;
are disease-causing microorganisms
can be fatal
A pathogens is any substance or organism especially microorganisms that are capable of causing diseases. Pathogens include; bacteria, viruses, protozoa or fungi. Microorganisms are not considered to be pathogenic until they have reached a population size that is large enough to cause disease. Pathogens can be fatal and can be treated. Pathogens are diverse and they occupy essentially every environment.
<h3><u>Answer;</u></h3>
d. a neuron recharges before it can fire again.
<h3><u>Explanation;</u></h3>
- <em><u>Refractory periods are a short phase in time following an action potential where another action potential cannot be generated. </u></em>
- <em><u>It is the period immediately following the transmission of an impulse in nerve or muscle, in which a neuron or muscle cell regains its ability to transmit another impulse. </u></em>
- There are two types of refractory period, that is the absolute refractory period and the relative refractory period. Absolute refractory period is the first part of a refractory period during which, the neuron will not fire again no matter how great the stimulation and this only lasts for a short time.
- Relative refractory period occurs when a stronger than usual stimulus is required to trigger the action potential before the neuron returns to resting state.
Answer:
The correct answer is - observation.
Explanation:
Scientists like Si-Ling Chi, Aristotle, and Mary Anning developed various scientific processes and made discoveries that shaped the history of the world. such discoveries are discoveries related to silkworms and how to make cloth from their cocoons by Si-Ling Chi, developing the scientific method by Aristotle and Contribution to the field of paleontology greatly by Mary Anning.
All these scientists had a different type of skill and ability and one of the skills they had a strong power of observing the things or phenomenon work and many more other aspects of the scientific process.
Answer:
The 5' end has free phosphate group while the 3' end has free OH group.
Explanation:
Each DNA strand has two ends that differ from each other with respect to the functional group. The nucleotide present at the 5' end of a DNA strand has a free phosphate group. This phosphate group of other nucleotides of the DNA strand is bonded in phosphodiester bonds. Likewise, the 3' end of a DNA has a free OH group. This makes the two ends of a DNA strand quite different from each other. A DNA new nucleotide can be added to the 3' end due to the presence of a free OH group.
