DNA because DNA always has a double helix
<span>Sex cells are called gametes. Gametes are haploid sex cells that are produced in gonads or gametangia. In animals, gametes are produced through meiosis in organs called gonads. In some primitive plants, algae, and fungi, gametes are produced through mitosis in haploid structures called gametangia.</span>
The correct answer is: B) G1
Normal cells (unlike cancer cells), move through the cell cycle in a regulated way in order to make sure that cells don't divide under conditions that are unfavorable for them. Information about their own internal state (nutrients, signal molecules, DNA integrity) is signal to go or not to go through the cell division. Because of that there are few checkpoints in the cell cycle at which the cell examines the signals and makes a “decision”. The major checkpoints are:
• The G1- the first point at which it must choose, once it passes the G1 checkpoint the cell enters S phase
• The G2-the cell checks DNA integrity and checks if replication is done well.
• The spindle checkpoint-at the transition from metaphase to anaphase.
Answer: The fertilized egg divides and the cells differentiate to become all of the different cell types of a human, the DNA molecules of the fertilized egg must be duplicated over and over, so that each of our trillions of cells contains an exact copy of the DNA contained in the fertilized egg.
Answer:
The fluid that is filtered out from the blood then travels down a tiny tube-like structure called a tubule. The tubule adjusts the level of salts, water, and wastes that will leave the body in the urine.
Urine leaves the kidneys and travels through the ureters to the bladder.
