Asap! describe at least one way in which each of earth’s subsystems was altered during the precambrian era.

The Precambrian Era is the largest on Earth, voering about 600m years, which is around 90% of Earth's age. Nota that this isn't an official era or period, so I recommend calling it "time".

A susystem is system, that functions independently, within another bigger system.

Given all that, let's work trough the differences:

During the precambrian time, some subsystems where not existent.

In the beginning, oceans, lakes and rivers didn't exist, since there still wasn't liquid on Earth.

Since there wasn't a source of water, trees where also inexistant and started develpoing only later on, when soil was adequate (but still in the precambrian era, remember, it covers about 600 million years).

The geopshere was also different at the start of the Precambrian time. It was more active, there still wasn't inactive volcanoes and these where more common and frequent.

The atmosphere was also very different. Gases at that time where different, and the concentration of these as well.

Hope it helped,

BioTeacher101

the corpus luteum secretes estrogens and progesterone. the latter hormone causes changes in the uterus that make it more suitable for implantation of the fertilized ovum and the nourishment of the embryo. if the egg is not fertilized, the corpus luteum becomes inactive after 10–14 days, and menstruation occurs.

i hope this : )

genetic variation will increase because of a new habitat and food source.

explanation: