Answer:
They are training animals in a maze and recording physiological changes in their brains, Stimulating a brain structure and recording subsequent changes in movement, Introducing two adults that are potentially attracted to each other, and then measuring their sex hormone levels, Measuring the brain volumes and intelligences of people in a group, Observing enlarged cerebral ventricles in the brains of many people with schizophrenia, Severing the connections between visual regions and the rest of the brain in animals, and observing the animals’ failure to recognize an object, and Studying the relationship between a sex hormone treatment and strength of an animal’s mating behavior.
Explanation:
Stem cells are what allow planaria to grow and regenerate as the stem cells can change into any of the cells that make up the planaria.
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:
Force, F = 90 N
Explanation:
Given that,
Mass of the bicycle and rider, m = 60 kg
Acceleration of the bicycle and rider, a = 1.5 m/s²
We need to find the force acting on the bicycle and rider to accelerate. Let it is F. Its force is given by :
F = ma
F = 60 kg × 1.5 m/s²
F = 90 N
So, the force acting on the bicycle and rider is 90 N.