U still have school its summer
Answer
The correct option is B.
Explanation
Ecological succession of any species is composed of following stages:
A. Migration
The movement of species from one place to another location for the purpose of setting permanently o temporary is known as migration
. Forexample
Siberian crane (<em>Leucogeranus leucogeranus</em>) that live in the arctic tundra of eastern and western Russia. The eastern population of birds migrate to china while western population of these birds migrate to Iran, India and Nepal during winter season.
B. Ecesis
The complete establishment of species in new habitat that was completely barren or left barren due to some catastrophe is known as Ecesion. This process is dependent upon the climatic, edaphic and biotic factors. The success of plant depend upon some of the adaptations to withstand the unfavorable conditions which includes both biotic and abiotic conditions.
Forexample
The process of succession in xerosphere start on barren area from pioneer stage covered by crustose lichen, then foliose lichen followed by moss stage, herbaceous stage and a last by shrub stage.
C. Nudation
The initiation of new species by major environmental disturbance such as volcano eruption is known as Nudation.
D. Reaction
It represents the effect of established species on the habitat. Forexample plants alter habitat condition as they grow. They extract raw materials from the environment in large amounts and return metabolic wastes. The waste accumulates in large amounts and differ from the original raw materials, thus altering the environment.
E. Competition
The phenomenon which involves struggle for existence between two or more individuals growing in same area, that make excessive demand that are similar in nature on the soil is known as competition.
Such struggle may be in between same species or different species. The competition may be interspecific or intraspecific. Because of completion the weak individuals are eliminated as strong ones are retained.
A phylogenetic tree,<span> or </span>evolutionary tree,<span> is a branching </span>diagram<span> or "</span>tree<span>" showing the inferred </span>evolutionary<span> relationships among various biological </span>species<span> or other entities </span>based upon similarities and differences in their physical or genetic characteristics. The taxa joined together in the tree are implied to have descended from a common ancestor<span>.</span><span />
Answer:
Option-A
Explanation:
Fertilization refers to the fusion of the male and female gamete to form the zygote.
When the fertilization occurs inside the organism through insemination then it is known as the internal fertilization and when it occurs outside the organism like observed in the amphibians when male and female gametes fuse in the water is known as external fertilization.
Both are different type of fertilization but share a similarity that is the formation of a single cell called the zygote which grows into the embryo by the mitotic division. The embryo later develops into the organism.
Thus, Option-A is correct.
