Answer: Aristotle and Ptolemy had both assumed each planet is attached to a single sphere, but geometers and astronomers could employ a number of such spheres to generate the observed motions of the planets.
Explanation:
Catalysts lower the Activation energy for reactions. The lower the activation energy for a reaction,the faster the rate. Thus enzymes speed up reactions by lowering activation energy. Many enzymes change shape when substrate ms bind.
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.
Correct question:
The hypothalamus __________.
a) influences the function of only one lobe of the pituitary gland.
b) synthesizes all of the hormones produced by the pituitary gland.
c) regulates both reproduction and body temperature.
d) produces only inhibitory hormones.
Answer:
C) Regulates both reproduction and body temperature.
Explanation:
The hypothalamus is a small but important area in the center of the brain. It plays an important role in hormone production and helps to stimulate many important processes in the body and is located in the brain, between the pituitary gland and thalamus.
The hypothalamus’ main role is to keep the body in homeostasis as much as possible.
Homeostasis means a healthful, balanced bodily state.
The hypothalamus acts as the link between the endocrine and nervous systems to achieve this. It plays a part in many essential functions of the body such as: body temperature, thirst, appetite and weight control, emotions, sex drive, blood pressure and heart rate, production of digestive juices and balancing bodily fluids.
I think the answer is D. A good indicator is the resting heart rate. Exercise strengthen your heart and it makes it more efficient. The resting heart rate shows of the heart is pumping blood normally each time it contracts. Having a normal resting heart rate would mean a healthy heart.
