A. <span>Exposure to an antigen
Exposure to viruses and antigens led to the foundation of modern vaccination. Vaccination introduces an antigenic material that helps the ability of the immune system to adapt a specific pathogen, therefore leading to a long-term immunity.</span>
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.
Answer:
The correct answer is - option A. 0%
Explanation:
The zygote formation or fertilization in flowering plants occurs by the fusion of pollen of one plant with the ovum of another plant of the same species normally. This process includes the exchange of an equal amount of the genetic contribution from both plants.
The egg cell of the mother is responsible for the mitochondria and chloroplast of the progeny so the percentage of chloroplast genes provided via Plant R is 0% as ovum and egg cell comes from only plant Q.
percentage of chloroplast gene inherited from R plant is a)0%
1. Number of chromosomes in the parent cell is 46
2. Number of chromatids in daughter cells formed by first division is 46
3. Number of chromosomes in daughter cells formed by first division is 23
4. Number of chromosomes in daughter cells of second division 23
5. Number of haploid cells formed by meiotic division of parent cell is 4
Answer:
1. It secretes a peptide/protein hormone.
Explanation:
The above mentioned answer is more likely true for this question.
Because, rough endoplasmic reticulum is the cytoplasmic organelles which are involved in post-translational modification of peptide chains. After that, peptide chains are further modified (folded) in golgi apparatus. It's means that abundance of rough endoplasmic reticulum and golgi apparatus present in cells ensure the formation and secretion of peptide/protein hormones.
