Answer:
DNA is also called deoxyribonucleic acid which is made up of two chains which wind around each other to form a double helix model. The 2 DNA strands are also called polynucleotides and they are made up of monomeric units known as nucleotides. These nucleotides are made up of one of four nitrogen-containing nucleobases: cytosine, guanine, adenine and thymine, a phosphate group, and sugar known as deoxyribose.
Nitrogen bases present on the two separate polynucleotides strands are bound together with the help of base pairing (such as adenine with Thymine) and with hydrogen bonds to form double-stranded DNA.
So, adenine in DNA is complementary to thymine.
Answer:
The main difference between sieve tubes and companion cells is that sieve tubes are the long, narrow, pointed tubes present in the phloem of angiosperms whereas companion cells are attached to the sieve tubes, regulating the activity of sieve tubes.
The right option is; c. biomes
Savanna is considered a transitional biome because it is intermediate between two biomes.
A savanna is a tropical grassland ecosystem that is characterized by widely spaced scattered trees. Savanna is an extensive plain that is regarded as a transitional biome because it is intermediate between moisture equator forests and tropical deserts. It covers about 20% of the earth’ surface. Savanna has seasonal water availability and during the dry season, there are strong evaporation which makes the trees such as baobab to shed their leaves while bushes and grasses wither.
Irritable Bowel Syndrome or IBS for short is known to be a common disorder that affects the colon. IBS causes alternating patterns of constipation and diarrhea. In treating IBS, it requires dietary changes and some medications, especially antibiotics. Some known medications made for IBS patients are known as Lotronex and Amitiza.
