Answer:
The cell cycle is controlled by many cell cycle control factors, namely cyclins, cyclin-dependent kinases (Cdks) and cyclin-dependent kinase inhibitors (CKIs). Cyclins and Cdks, which are positive regulators of the cell cycle, activate cell cycle factors that are essential for the start of the next cell cycle phase.
Explanation:
Listen to pronunciation. (sel-SY-kul REH-gyoo-LAY-shun) Any process that controls the series of events by which a cell goes through the cell cycle. During the cell cycle, a cell makes a copy of its DNA and other contents, and divides in two.
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:
1. Cell
2. cell theory
3. Organismal theory
4. resolving power
Explanation:
The cell is the smallest known unit of all living organisms. They are called the building blocks of life. An organism can be unicellular (made up of one cell) or multi-cellular (made up of many cells).
2. Cell theory was formulated and developed by Schleiden, Schwann, and Virchow. They are considered as the basic principles of biology.
It states:
1. Living organisms are made up of cells.
2. Cells are the basic unit of life.
3. Cells are formed from pre-existing cells.
4. Energy flows inside the cell.
5. DNA is passed on from cell to cell.
6. All cells have the same basic chemical composition.
3. Organismal theory is the intended counter-argument of the cell theory. It was developed by Reichert, Strasberger, Sherrington, and Pavlov. It argues that the basic unit of life is the organism itself, suggesting that an organism came about from a cell that expanded.
4. Resolving power is the ability of an optical instrument like a microscope or a telescope to view objects that are close together as separate, abling the viewer to distinguish the two from each other.
I think c and d is the best answers
