The correct options are as follows"
1.B.
Postzygotic isolation is a type of reproductive isolation which keeps species from mating with each other as a result of the differences that developed between them when they are separated by physical boundary. In the question given above, the lizard specie has been separated by the formation of a stream which divide the region into two.
2.B.
Allopatric speciation refers to the mode of speciation that occur when biological population of the same specie become isolated from each other to an extent that it interferes with genetic interchange. It usually occur as a result of change in the environment.
1/4 recessive can be expected for the recessive trait of mono hybrids from the F2 generation.
Option D
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Explanation:</u></h3>
Mono hybrid cross is defined as the crossing between two plants considering the two different alleles of a particular character. It was 1st performed by Father of Genetics, Sir Gregor Mendel. The mono hybrid cross done by him considered the character tallness of garden pea plants, of which one was tall and other was short.
He crossed them to get all tall plants in 
Filial generation. Now as he self bred those plants, he got the tall and short plants in ratio of 3:1. Thus he proved that the recessive trait of mono hybrids is 
of the total population of F2 generation.
The lining of the back of eye containing two types of photoreceptor cells - rods - sensitive to dim light and black and white - and cones - sensitive to colour. A small area called the fovea in the middle of the retina has many more cones than rods.
Answer:
Because your final periods can be irregular, menopause is confirmed 12 months after your last period. It is not normal to bleed or spot 12 months or more after your last period. Bleeding after menopause is usually a sign of a minor health problem but can sometimes be an early sign of more serious disease.
Answer:
The core controls and controls the exercises of the cell (e.g., development and digestion system) and carries the qualities, structures that contain the innate data.
Atomic pores, little channels that span the atomic envelope, let substances enter and exit the core. Each pore is lined by a set of proteins, called the atomic pore complex, that control what atoms can go in or out.
The core is spheroid in shape and isolated from the cytoplasm by a layer called the atomic envelope. The atomic envelope confines and ensures a cell's DNA from different atoms that seem incidentally harm its structure or meddled with its handling.
