Answer:
c
Explanation:
catalysts are used up in a chemical reactiob
During exercise, a number of changes occur to maximise the body's oxygen intake. Firstly our heart rate/ pulse increases. This is due to the heart beating much faster and more forcefully to pump blood faster around the body.
Our breathing rate increases to intake more oxygen and exhale more CO2.
The smooth muscle in our trachea and bronchi relaxes to increase the lumen size thus making breathing easier. Adrenaline may also be released leading further amplifying these changes as well as reducing blood flow to the gut and thus peristalsis occurs at a much slower rate.
Also when we exercise we respire more, producing heat, which must be expelled. This may be done through sweating. Another physiological change that occurs is vasodilation of arterioles closer to the skin to allow more blood to flow closer to the skin, allowing more heat to radiate out.
Answer;
Transport of substances
Explanation;
-Veins have vascular tissues, that is the xylem and the phloem. Xylem tissue transports water and mineral salts to the leaf, while phloem transports manufactured food from the leaf to other parts of the plant.
-Leaves need water for photosynthesis and the water is transported from roots to leaves through xylem.
-Veins are spread all over the leaves ,so they can easily transport water to all the cells of leaves.
-After the completion of photosynthesis in a chloroplasts, glucose is formed which may be used for cellular respiration or stored in form of starch. Phloem transports the glucose to other parts of the plant for cellular respiration;
Protects the body tissues against injuries
Explanation:
The Chandra X-ray observatory or CXC for its acronym in English, is an artificial satellite launched by NASA on July 23, 1999. It was named in honor of Indian physicist Subrahmanyan Chandrasekhar, one of the founders of astrophysics, who determined the boundary mass at which white dwarfs become a neutron star. In addition, Chandra means "moon" in Sanskrit.
The Chandra Observatory is the third of the Great Observatories of NASA. The first was the Hubble Space Telescope, the second was the Gamma Compton Ray Observatory, launched in 1991 and already disintegrated, and the last was the Spitzer Space Telescope. Before launching the Chandra Observatory was known as AXAF by the acronym in English of Advanced X-ray Astronomical Facility.
As the Earth's atmosphere absorbs most X-rays, conventional telescopes cannot detect them and a space telescope is necessary for their study.
In 1976 Riccardo Giacconi and Harvey Tananbaum proposed to NASA the idea of the Chandra Observatory, beginning preliminary work at the Marshall Space Flight Center. Meanwhile, in 1978, NASA launched the first X-ray space telescope, the Einstein (HEAO-2).
Despite this, work on the Chandra project continued during the 1980s and 1990s, but in 1992 the ship was redesigned to reduce costs. Four of the twenty mirrors that the observatory was going to dispose of were removed, and an elliptical orbit with which it would reach a third of the distance to the moon was calculated. This eliminated the possibility of being repaired by the space shuttle, but placed the observatory outside the influence of the earth's radiation belts most of its orbit.