There is a valve at the meeting point between each ureter and the bladder prevents the back flow of urine from the urinary bladder to the kidney
Answer:
food chain
A food chain is a linear sequence of organisms through which nutrients and energy pass as one organism eats another. In a food chain, each organism occupies a different trophic level, defined by how many energy transfers separate it from the basic input of the chain. pls marl me asfood chain
Brainliest
Any chemical substance which forms naturally in the earth is called a mineral.
<h3>What is mineral?</h3>
A chemical compound having a specific crystal structure that occurs naturally in pure form or formed naturally in the earth is known as mineral.
So we can conclude that any chemical substance which forms naturally in the earth is called a mineral.
Learn more about mineral here: brainly.com/question/15844293
Answer:
C) Only if her intake is consistently less than 70% of the RDA would she be at great risk of nutritional deficiency.
Explanation:
Recommended dietary allowance is the amount of nutrients that are sufficient to maintain a good health. RDA is set by Food and Nutrition Board of Institute of Medicine to meet the requirements of (97%-98%) people. If someone is consuming lower level of nutrient than RDA it may be deficient or may not be because the requirement of every person varies. But if a person is consuming consistently less than 70% of the RDA, he would be at great risk of malnutrition.
RDA only tells about adequate amount of nutrients like minimum amount that should be taken by a person to remain healthy. However there are tolerable upper level intake (UL) which indicates the maximum amount of nutrients that could be taken by a person.
Only if Tina intake is consistently less than 70% of the RDA she would be at great risk of nutritional deficiency that why she has no condition warranting a greater-than-normal need for iron.
ON THE GEOLOGICAL TIME SCALE SILURIAN IS THE ERA DURING WHICH FIRST VASCULAR PLANTS APPEAR ON EARTH.
Explanation:
The geological time scale is the system used by the geological scientists to describe history of earth in terms of geological events which means formation of new rock layer. Geological time scale is divided into units and sub-units,the largest of which are Eons, Eons are divided into Era's which are further divided into periods,epochs,ages.
In this periods which are sub division of Era's are divided into multiple in number, Of these periods in the paleozoic period and in silurian era first vascular seedless plants appear on the earth. So, on the geological time scale, silurian is the era during which first seedless vascular plants appear on the earth.
