Answer: (B) Pre-zygotic; post-zygotic.
Explanation:
Prezygotic isolation occurs before fertilization of eggs. It occurs between the two sex gametes and deter sexual reproduction between different species.
However, individuals are considered to be diverge on the phylogeny tree and different species, when they cannot reproduce.
Mechanisms of prezygotic isolation include habitat isolation, gamete isolation, mechanical isolation, behavioral isolation, and mating seasons.
Whereas, postzygotic isolation prevents the formation of fertile offspring. This phenomenon leads to production of an hybrid offspring from different species and this is a form of speciation in nature.
Mechanisms of postzygotic isolation include hybrid inviability, hybrid breakdown, and hybrid sterility.
Answer:
The eukaryotic plant animal cells are differ having some cell organelles in it.
Explanation:
The first difference is the cell wall, which is present in all eukaryotic plants. It gives shape and rigidity to the plants. But all the animal cell the outer covering is cell membrane. They lack cell wall.
All the plant cell have chlorophyll pigment. It helps them to photosynthesis. In animal cell, chlorophyll molecule are absent. So they depend on plants for their food.
The eukaryotic plant cell more space is occupied by the vacuoles. It stores food and water for the plants. However, animal cells have no vacuole or if present, it is very small in size.
All animal cells have lysosomes, which help in digestion of various materials in the cell. Plants does not contain lysosomes.
Besides this organelles all other structure of plant and animals are similar. They both have nucleus, DNA, cytoplasm, mitochondria, etc.
Answer:
Option (b) Both are polymers of D-glucose but cellulose is connected by ( beta 1-4 ) glycosidic linkage whereas glycogen is connected by ( alpha1-4) glycosidic linkage....
Explanation:
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False incubation is when there is no symptoms but ur sick
