Answer:
signal molecule is a general term for molecules also called (ligands)that bind specifically to other molecules (such as receptors). hope it helps!!
CO2 traps heat in the atmosphere of the earth which leads to global warming because of the green house effect
Answer:
A) The two strands of a DNA molecule are parallel and complementary.
Explanation:
DNA is a polymer of nucleotide and this nucleotide are made up of a deoxyribose sugar molecule, a nitrogenous base, and a phosphate group. In DNA genetic information of the cell is stored in the form of nitrogenous bases.
DNA is double-stranded and both the strands run anti-parallel with each other. This anti-parallel orientation provides the nitrogenous base of one strand to form hydrogen bonds with the nitrogenous base present on the opposite strand.
In DNA adenine base pairs with thymine with two hydrogen bonds and guanine base pairs with cytosine with three hydrogen bonds. So the false statement is A.
Explanation:
Meiosis makes genetic variety possible. It makes sperm & egg cells called gametes. Each gamete has 23 chromosomes. To make a diploid cell two gametes (sperm & cell) come together.
During prophase 1 the chromosomes pair up with their homologous pairs so they can transfer their genetic information and exchange it between each other. It makes recombinant chromosomes that influence the genetic diversity between the same people.
Now they are in metaphase 1, the chromosomes are in pairs in the middle of the cell. In anaphase 1, the chromosomes are pulled away by the spindle fibers. Then in telophase 1, there are two formed nuclei. Cytokinesis 1 then splits the cytoplasm.
Now they are in meiosis 2. During prophase 2, there are chromosomes and the spindles are starting to form again without crossing over like in prophase 1. In metaphase 2, chromosomes are going to line up in the middle in both cells unlike during metaphase 1 where the chromosomes were only in pairs. In anaphase 2, only the chromatids are being pulled away by the spindle fibers. Next in telophase 2 the nuclei reform and the 2 cells are each going to divide into 4 cells. Finally, cytokinesis completely splits the cytoplasm.
Keeping in mind that each sex only produces one type of gamete cell (sperm or eggs), and of the independent assortment and crossing over of chromosomes, the end result will be diversity.
