Step 2 should be sensory neurons send electrical signals to the brain
Step 3 brain learns information about the environment
Step 4 brain sends electrical signals to the muscles
Answer:
A) Chromosomes are made of DNA
C) Alleles are the different forms of a gene that can exist
D) Chromosomes contain genes that control the inheritance of traits.
Explanation:
Chromosomes are long molecules of deoxyribonucleic acid (DNA) that contain part (or all) of the genetic material of an organism. Humans contain 46 chromosomes organized in 23 pairs of homologous chromosomes (22 pairs of autosomal chromosomes and one pair of sex chromosomes, X and Y). Moreover, a gene is a physical segment of a chromosome that contains the information to encode a protein. Alleles are different forms of a gene (i.e., gene variants) that may be caused by mutations or genetic recombination. Humans are diploid organisms (2N: 46), and therefore we have two copies of each gene (alleles), one on each homologous chromosome.
GRIMNER
Grow
Reproduce
Irritability (ie, being able to sense changes in the environment, detect danger, etc.)
Movement
Nutrition (eating and drinking)
Excretion (get rid of waste materials)
Respire (breathe)
The answer is an enzyme.
When cutting DNA, scientist uses enzymes called restriction enzymes. These enzymes are naturally produced in bacteria as a defense against phages. So, enzymes cut DNA of the phages and thus inactivate it. Also, these enzymes do not cat DNA randomly, but on specific sites. This characteristic of restriction enzymes is used for some molecular biology techniques. All species' DNA contains target sites of restriction enzymes, but most organisms do not have restriction enzymes. Therefore, restriction enzymes are suitable for different techniques.
The correct answer is - D) covered by warm shallow seas.
The fact that the crinoids are have an abundance in the fossil records in Pennsylvania in the Mississippian Period, tells us that this area was covered with shallow and warm seas. The reason why we can get that conclusion is that the crinoids live only in that kind of environment, so it simply a logical conclusion.
The geological data is also confirming this, as it is easily noticeable in the layers that during this period of the geologic past, what is now Pennsylvania, was covered with shallow sea waters. Also, this waters were warm too, as the climate was warm and humid and that period, so it was a perfect environment for the crinoids to flourish.