Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
I don't understand, what is the question you're supposed to answer?
Answer: pituitary gland
Explanation: In an oophorectomy procedure as both ovaries were removed due to which hypothalamus, pituitary and ovarian axis mainly damaged. When ovaries removed than LH (luteinizing hormone) and FSH ( follicle stimulating hormone) level increased by the pituitary gland. The hormones that are produced by ovaries also decrease in which estrogen and progesterone level decreased which cause list of problems in females.
I am going to go with steroids because they are a type of lipid.
The fertilized egg begins a rapid descent to the uterus. The period of rest in the tube appears to be necessary for full development of the fertilized egg and for the uterus to prepare to receive theegg. ... At the end of this transition period, the embryo becomes a mass of very organized cells, called a blastocyst.
