Answer:
A-T
Explanation:
purine adenine (A) always pairs with the pyrimidine thymine (T)
pyrimidine cytosine (C) always pairs with the purine guanine (G)
Answer:
Watson and Crick proposed the double helical model of DNA.
Explanation:
- This model says that DNA exist as double helix. It has two polynucelotide strands running in opposite direction i.e the strands are anti-parallel.
- Each polynucleotide strand is made up of several nucleotide liknked together by phophodiester bonds.
- The two strands are not coiled upon each other but the double strand is coiled upon itself around a common axis like the spiral stair case. Here base pairs forms the stairs and backbone of two strands form railing. Back bone contains sugar and phosphate.
- The base pairing is specific, adenine always pairs with thymine and guanine always pairs with cytosine. Thus if we see any base pair, it consists of one purine and one pyrimidine.
- The two strands of DNA thus show complementary base pairing.
- The strands are held together because of hydrogen bonding between the bases in opposite strand.
- One full helical turn involves ten base pairs and the base pairs are stacked 3.4 A apart.
- This form is called as B-form of DNA.
Answer:
Element is a substance that cannot be broken down into simpler substances. Atoms are the smallest particle of an element. An element has a fixed composition because it contains only one type of atom.
Answer:
The correct option is D: Being prepared for harsh weather conditions
Explanation:
Plants are sensitive to the changes in the environment and any drastic changes in their surroundings can potentially cause the plant to go into stress, or possibly even die. Too high or low a temperature and the plant will not be able to cope. Similarly, drastic changes in water levels will really affect its health and growth.
Hope that answers the question, have a great day!
Answer:
Phylum Chordata - Advanced
Includes: Tunicates, Lancelets, and Vertebrates (which include Fish, Amphibians, Reptiles, Birds and Mammals)
Explanation:
Correct me if I'm wrong
