Answer:
meiosis
Explanation:
Down syndrome is an abnormality that occurs on chromosomes 21, it occurs because chromosomes 21 cannot be separated in meiosis, the pair of chromosomes 21 do not separate and go together to one of the daughter cells. In this way, the oocyte or the resulting sperm will have 24 chromosomes instead of 23. When in conception that oocyte or sperm joins the germ cell of its partner that contributes the 23 chromosomes, the total sum of chromosomes that will have the first cell of the new conceived being will be 47.
The correct answer is A. Lac repressor.
Lac repressor prevents lac gene which are found in the DNA of Escherichia Coli from being expressed for many times.
Lac repressor is termed as DNA which binds proteins. It allows the expression of genes from coding which are made for proteins to be involved in metabolism of lactose which is in bacteria.
When there is no lactose which is available in the cell, then the genes are being repressed. Lactose are being converted to allolactose if they are available.
Answer:
evolutionary theory of sexual behavior.
Explanation:
Answer:
C) esophagus - moves air from the nose into the lungs
Explanation:
The oesophagus is a muscular tube with a sphincter valve at each end. Its main function is to transport food and fluid, after being swallowed, from the mouth to the stomach.This is propelled from the pharynx into the oesophagus, and towards the stomach in a peristaltic waves. The peristalsis also pushes food along the alimentary canal
The answer is C: Diploid (meaning there are 2 sets of chromosomes, one set from maternal and one set from paternal)
One CHROMOSOME from each SET will form a homologous pair
