Cerebrospinal Fluid
Produced by the choroid plexuses of the brain, the cerebral spinal fluid is contained in the subarachnoid cavity and spinal canal. It is reabsorbed by the arachnoid granulations.
Besides acting as a cushion for the CNS, the cerebral spinal fluid plays a critical part in the immunology of the central nervous system, blood flow in the CNS and autoregulation.
D. DNA
All organisms contain dna
the organisms have varying traits, like different colored eggs because of the natural selection.
<h3>What is the process of natural selection? </h3>
Natural selection is one of the main mechanisms of evolution. In a very simple way, we can say that natural selection is a process in which the fittest organisms are selected, survive in the environment, reproduce and pass their characteristics on to their descendants.
the color change of an egg occurs by natural selection and also by genetic variability. since the environment will select the best ones to survive and mutations will occur. Natural selection will forcefully change the environment causing only a few species to survive.
See more about natural selection at brainly.com/question/9830102
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2 Tt and 2 tt or 50% for both heterozygous and homozygous recessive your welcome.