In photosystem I, P700 transfers an a. electron to chlorophyll (A0) upon excitation by a photon. b. The electron is replaced by electrons generated by the proton gradient. c. electrons donated directly from plastoquinone at QA. d. the splitting of water molecules at the manganese center. e. oxidation of pheophytin. electrons donated from NADPH. f. electrons transferred from plastocyanin.
Some problems with use of DNA analysis for forensic evidence may occur because ofidentical twins.
not enough of a sample.
All of the above.
Answer: Option D " all of the above "
Explanation: DNA can be a great source of information when used as a forensic evidence. This technique has many advantages and disadvantages when used as a source of information in case of crime.
Identical twins: There are some common fragments of DNA that is same in identical twins so it can be a difficulty in deciding the criminal.
Not enough of a sample: DNA should be present in a detectable amount to be used an sample for evidence, less than this detectable amount is a waste and cannot be used as a sample for evidence.
Contaminated and degraded sample: If the sample of DNA is contaminated or degraded then the result might be incorrect and might not be used as a sample for forensic evidence.
Hence, the correct answers are all of the above.
4. An increase in calcium concentration in the sarcoplasm will cause which of the following?A. displacement of troponin tropomyosin complex from the actin binding sites B. muscle relaxation C. rapid repolarization of the muscle membrane D. breaking of the actin/myosin cross-bridges E. activation of calcium pumps in the sarcoplasmic reticulum
B. muscle relaxation
Sarcoplasmic reticulum store intracellular calcium in skeletal muscle cells.
The concentration of calcium helps in the contraction and relaxation of muscles. During depolarization, the calcium concentration increases that change conformation of troponin and tropomyosin and allows the actin to bind with myosin, resulting into relaxation of the muscle cell.
Hence, the correct option is "B. muscle relaxation".
According to modern evidence, homo sapiens originated from spread out from there. and O A. Europe O B. Asia O c. Africanew a. p. a. e. x.
it is Africa
Walking alone late one night, you are startled by a moving shadow that you glimpse out of the corner of your eye. The _______ division of the autonomic nervous system is activated. When you realize it is just the neighbor’s pet, the _______ division lessens your physiological arousal.
Walking alone late one night, you are startled by a moving shadow that you glimpse out of the corner of your eye. The sympathetic division of the autonomic nervous system is activated. When you realize it is just the neighbor’s pet, the parasympathetic division lessens your physiological arousal.
The sympathetic division of the autonomic nervous system activates when you're startled, initiating the 'fight or flight' response. Once the danger has passed, the parasympathetic division lessens physiological arousal, returning the body to a restful state.
The autonomic nervous system (ANS) is a part of the peripheral nervous system that acts primarily unconsciously and regulates bodily functions. When you were startled by a moving shadow, the sympathetic division of the ANS was activated, stimulating your 'fight or flight' response and increasing your heart rate, dilating the pupils, and halting digestion. Then, after realizing it was just the neighbor's pet, the parasympathetic division stepped in, reducing your physiological arousal by slowing your heart rate, constricting your pupils, and resuming digestion, thus restabalizing your body conditions.