Protons have a positive charge. The number of protons in a nucleus determines the identity of the atom (element) and this number is called the atomic number.
D. Proton
Mussels are molluscans and are freshwater animals. The change in the environment led to new traits of mussels, it underwent natural selection and the thick shells have high chances of survival.
<h3>What is natural selection?</h3>
Natural selection is a process of nature that eliminates the organism with less survival and unfit traits while selecting the organisms with better traits of survival in the altered conditions.
The arrival or the introduction of the crabs in the environment altered the previous habitat of the mussels and led to the adaptation of the better trait quality in the mussel species.
The trait of the thick shells underwent natural selection as they were favoured for the changed conditions. The mussel having thick shells have high chances of survival over thin-shelled mussels as the crab will find it hard to attack the thick-shelled mussels.
Therefore, option A. change in environment, option B. natural selection and option E. chances of survival are the correct statements.
Learn more about the natural selection here:
brainly.com/question/10715606
Hip. the shoulder and hip form the only ball an socket joints in the body.
The answer is A. Fertilizer
The other answer choices don't make sense Herbicide is a poison that kills plants, Pesticide is an insect killer, while a Growth Hormone is designed to help the plant grow not to put nutrients into the soil.
Molecules brought in and used in the calvin cycle - Carbon dioxide 
, Ribulose bisphosphate (RuBP)
Molecules produced during the calvin cycle that leave the cycle - a few of the glyceraldehyde-3-phosphate (G3P), NADP+
Molecules used and regenerated within the calvin cycle - most of the Glyceraldehyde-3-phosphate (G3P) , NADPH
<u>Explanation:</u>
Calvin cycle is the light independent reaction that takes place in the stroma of the chloroplast. Calvin cycle uses ATP and NADPH produced during the light reaction. Calvin cycle occurs in 3 steps, they are:
1. Carbon fixation - combines with Ribulose bisphosphate (RuBP) to form 2 molecules of 3-phosphoglyceric acid (3-PGA).
2. Reduction - ATP and NADPH is used to convert 3-PGA into glyceraldehyde-3-phosphate (G3P).
3. Regeneration - some G3P molecule form glucose while other regenerates to form RuBP acceptor.
