Answer:
The correct answer is option A, Gastrula
Explanation:
Gastrula has three layers of cell and it is the phase in which single layered blastula matures and get converted into multilayered structure.
However, Morula is formed after the formation of blastula through the process of blastulation. In the Morula phase, blastomers get arranged in a spherical shape after the zygote split. And zygote is formed at a very early stage of fertilization .
Thus , gastrula is the correct answer as it is the stage which comes after zygote and morula and thus get developed into more compact mass of cells.
Answer:
All the puppies have black hair because albino alleles are found in two different genes.
If we let the letters A and B represent the two different pigmentation genes, the one of the dogs is AAbb, and the other is aaBB.
Their offspring are AaBb and so there are not albinos because they have one dominant copy of each gene.
If a researcher electrically stimulates the reticular formation in an animal, the animal will immediately wake up and be alert. Its purpose is to have some control of sensory signals and thus has the ability to alert the body when it is tired or needs to be awake.
Answer:
option B. cohesion..........tree.
The potato crop devastation occurred in Ireland for not using one single potato species.
Explanation:
Potato became the staple crop of 18th Century Ireland and was easy to grow in the soil of this place. Later, it became the most dependent crop of the people of Ireland which made its supply very demanding leading to the yielding of more than one species of potatoes.
This yielding reduced the variety in the genetics of potatoes that helped in preventing the disease that affect potatoes by making the Irish people susceptible to famine. The Phytopthora bacteria affected the potatoes of North America in the year 1840 and Ireland’s moist weather in that same year made the blight to thrive.
