Answer:
The correct answer is -
1. Adenine - 10%
2. A-T and C-G always in DNA.
Explanation:
1. The total amount of all nitrogenous bases are equally 100% and which includes an equal amount of C and G and an equal amount of A and T in the DNA molecule.
So, Cytosine = 40%, Guanine= 40%
total = 80%
therefore, the A and thymine would be - 100 - 80 = 20
A+T = 20
A= 10, and, T = 10%
2. The complementary base pairing rule explains that DNA base pairs are Adenine always binds with thymine and cytosine bind with guanine only. Purine binds with pyrimidine always except - A-C or G- T.
Answer:
Fossil record is used to study macro evolution.
Explanation:
Macroevolution may be defined as the change above the species level. Fossils are the impressions of dead plants and animals buried under the surface of rocks.
Fossils provide the direct evidence of macroevolution. For example : Paleozoic era was dominated by trilobites, crinoids and brachiopods. Rocks that one part of paleozoic era are now contains the fossils of trilobites, crinoids and brachiopods. These species may either extinct or not common in today's world. Thus, fossil record can be used to study macroevolution.
Answer:
The correct answer is both.
Explanation:
- Each chromosome is made up of a pair of sister chromatids which remain attached to each other at the centromere.
- During DNA replication the DNA duplicates, which means that if initially in the parent cell 'n' chromosomes were present then, after duplication, the number of chromosomes in the cell will be '2n'.
- As mentioned above, each chromosome has a pair of sister chromatids, that is, two chromatids per chromosome. So, 'n' chromosomes will have '2n' chromatids. Hence, '2n' chromosomes will have '4n' chromatids.
- In a parent cell,
- Before duplication, number of chromosome = n, number of chromatid = 2n.
- After duplication, number of chromosome = 2n, number of chromatid = 4n.
- The cell cycle proceeds as, G0, G1, S, G2, M.
- G0 represents the interphase. It occurs before replication or duplication of the chromosomes, which occurs in the S phase.
- So, in G0 phase, the chromosome number is 'n' and chromatid number is '2n'.
Answer:
- Animal cells have centrosomes (or a pair of centrioles), and lysosomes, whereas plant cells do not. Plant cells have a cell wall, chloroplasts, plasmodesmata, and plastids used for storage, and a large central vacuole, whereas animal cells do not.
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