During the prophase the nucleoli in the nucleus disappear. The chromatin fibers become tightly ccoiled and condense into chromosomes. Chromosomes line up in pairs and are joined at the centromere. In the cytoplasm, the spindle fibers begin to formand are made of microtubules.
The answer is hard tissue.
Usually, hard tissue, such as bones and teeth or exoskeleton is much more preserved than soft tissue (organs, skin, etc.). Fossils become fossils by a process of mineralization. Hard tissues are more mineralized during life than organs. So it is no surprise that hard tissues take part in the process of mineralization and is preserved in fossils, unlike soft tissues.
Answer:
D
is the answer because as you see the percentage increase
Question: Describe how a single amino acid substitution causes hemoglobin molecules to stick together. Use what you know about the structure of Hb and HbS, the properties of glutamic acid and valine, and how hydrophobicity causes molecules to behave in water.
Answer:
A Single amino acid must be polar to attract, just like water.
Explanation:
Sickle cell is an genetic illness and it is began by a alteration that arises in the beta sub units of the haemoglobin. Haemoglobin is a tetrameric protein made up of 2 alpha sub units and 2 beta sub units and it is the important part of the blood accountable for oxygen passage. Sickle cell is a illness that consequences from a replacement of a polar amino acid identified as glutamate with a non polar one valine at site six of the beta polypeptide component of haemoglobin. The replacement occurs as a consequence of a alteration in one of the bases in the beta-globin gene from adenine to thymine . As a outcome of this change, the beta polypeptide chains convert sticky in low oxygen circumstances since the valine sticks out of the chain and interrelates with neighboring non-polar amino acids.