Answer:
a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
"chlorine acts as a catalyst promoting the breakdown of ozone"
a person or thing that precipitates an event.
"the governor's speech acted as a catalyst for debate"
Explanation:
hope its help
Is known as Phloem. Its counterpart Xylem helps to transport water
Answer:
top two are recessive if not shaded
Explanation:
bottom one is dominant male
Answer: option d.hydrogen bonds between nitrogen base Pairs
Explanation:
DNA is called a Deoxyribonucleic acids, it contains hereditory information in the cell. DNA is located in nucleus of human cell. DNA consist of nucleotide strands that comprises of a sugar and oxyribose bound on a partto a phosphate group and bound on the other part to a nitrogenous base. The Nitrogenous base consist of Adenine, thymine, guanine and cytosine which are complementary base Pairs. They are grouped into 2 distinct classes called purines (double-ringed structures) and pyrimidines (single-ringed structures). The nitrogenous bases forms a ladder and pairs with bases on the other side commonly called rungs. Each complementary nucleotides purine with pyrimidine are held together by hydrogen bonds.A hydrogen bond is a known as chemical bond that is relatively weak and occurs only between hydrogen atoms along with or and electronegative atoms, e.g oxygen, nitrogen e.t.c. Hydrogen bonds usually occur in short length or distances and are formed quickly or easily and ca also broken.
