Answer:
1. Molecular evidence: similar proteins and genes found in closely related species, even if those genes are not used by an organism.
2. Fossil evidence: organisms changing form over time through the fossil record.
Direct observation. We can directly observe small-scale evolution in organisms
with short lifecycles (e.g., pesticide-resistant insects).
Explanation:
The answer would be : a. angiosperms.
Source : https://en.wikipedia.org/wiki/Flowering_plant
Hope this helps !
Photon
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.
Carbon cycle refers to an array of procedures by which the compounds of carbon are interconverted in the environment, comprising the inclusion of carbon dioxide into living tissue by the process of photosynthesis and then getting back into the atmosphere via respiration, the burning of fossil fuels, and the decomposition of dead organisms.
The following are the steps that illustrate how the carbon cycle functions:
1. Carbon enters the atmosphere as carbon dioxide from combustion and respiration.
2. The absorption of carbon dioxide takes place by the producers to manufacture glucose in photosynthesis.
3. The animals feed on the plant passing the carbon components through the food chain. The majority of the consumed carbon is exhaled in the form of CO2, which was produced at the time of aerobic respiration. The plants and animals die eventually.
4. The dead plants and animals get dissociated by the dead organisms and return the carbon present in their bodies back to the atmosphere as CO2 by the process of respiration. In certain occasions, the dead plant and animals get converted into fossil fuel, which is available in future for combustion.
