The scientist who developed the concept of 'natural selection' independently of Darwin was:
A. Jean-Baptiste Lamarck
B. Charles Lyell
C. Alfred Russel Wallace
D. Thomas Malthus
Answer: Option C
Solution (By JKSSB Mock Tests)
Alfred Russel Wallace, a British naturalist, independently arrived at the theory of evolution by natural selection. His 1858 essay, sent to Darwin, prompted the joint presentation of their ideas. Darwin then published 'On the Origin of Species' in 1859. Malthus influenced population thinking, Lyell geology, Lamarck earlier evolutionary ideas.
Explanation:
Adenine (A) pairs with thymine (T) via two hydrogen bonds. Guanine (G) pairs with cytosine (C) via three hydrogen bonds. This base pairing (complementarity) is key to the double helix structure and ensures accurate replication and transcription. The higher number of bonds between G-C contributes to DNA stability; GC-rich regions are harder to denature.
Explanation:
The left ventricle pumps blood into the aorta and to the systemic circulation. Its wall is the thickest because it must generate high pressure.
Explanation:
Fertilization is the union of a haploid sperm and a haploid ovum to form a diploid zygote. Pollination is pollen transfer in plants, implantation is embryo embedding in uterine wall, cleavage early mitotic divisions.
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