Answer:
first and third one
Explanation:
animals need the oxygen they make. and animals eat the plants. if an animal doesnt eat plants it eats somthing that does. sorry for the typos.
They concluded that horses evolved with the emergence of grasslands and an increase of predators. The digits of their early Eocene ancestor evolved into hooves.
<span>The purpose of the kidneys is to filter waste from the blood, and other things like water, glucose, amino acids, some minerals/vitamins, and other small molecules can also get filtered out. Reabsorbtion of water in the kidneys allows the body to maintain a fluid balance (drink a lot and you pee more cause you have an excess of water). As for the other aforementioned things, they're often needed for metabolic processes (such as certain enzyme functions) so loosing it to waste decreases efficiency and efficacy of other bodily processes. </span>
DNA model given by Watson and Creek in the year of 1953 gave a very detailed study regarding the structure of B DNA which is valid till date and is essentially corroborating with Chargaff's data and Xray diffraction pattern.
<h3><u>Explanation:</u></h3>
The DNA is the most common nucleic acid found in the living organisms as a genetic material. As stated by Watson and Creek, this DNA contains a double helical structure with two sugar phosphate backbones and the nitrogen bases getting projected from it inwards. The backbones are formed of ribose sugar and phosphate and joined together with a phosphodiester bond. The ribose sugar is attached to phosphates at its 3' and 5' Carbon atoms. The nitrogen bases found in DNA are Adenine, Guanine, Thymine and Cytosine. The Adenine has two hydrogen bonds with thymine and guanine has 3 hydrogen bonds with cytosine.
Each full turn of a helix is 34A and each base pair is 3.4A apart. The distance between two strands of DNA is 20A.
Chargaff's rule regarding the equal amount of adenine and thymine as well as guanine and cytosine is matching with this structure. All the other rules also do match with this DNA structure.
In contrast to the stratified squamous epithelium of the skin, the intestinal barrier is composed of a single layer of columnar epithelial cells However, this single layer of intestinal epithelial cells is made of diverse cell types with absorptive, secretory, and immune function