Answer:
Researchers initially built up the geologic time scale by considering rock layers and record fossils around the world. With this data, researchers put in Earth's stone layers in request by relative age. Afterward, radioactive dating decided the supreme age of the divisions in the geologic time scale.
Answer:
c) receptor; control center; effector.
Explanation:
Homeostasis maintains the internal body conditions almost constant. It includes specific cells that sense any deviations of internal or external conditions from the normal range. These cells are called receptors. The sensory information from the receptors is delivered to the control center. The central nervous system mainly serves as a control system wherein sensory information from the receptors is processed. The control center commands muscles and/or glands to perform desired responses to restore the homeostasis. Here, muscles and glands serve as effectors.
For example, thermoreceptors sense the rise of body temperature and the brain (control center) commands sweat glands (effectors) to produce sweat.
Answer: The correct answer is -
D. They determine the inherited traits of an organism.
Gene can be described as segment of DNA (deoxyribonucleic acid) that codes for particular protien, which determines specific trait (which is an inherited trait) of the organism.
Genes are located on chromosomes as considered as the unit of heredity as they are passed from one generation to the next generation.
Examples for inherited trait include eye color, skin color, hair shape and color etc.
Thus, option D) is the right answer.
Answer:
A) The striations are due to the orderly arrangement of actin and myosin
Explanation:
Smooth muscles are non-striated involuntary muscles which are found in the walls of stomach, urinary bladder, blood vessels...Smooth muscle tissue is composed of spindle-shaped muscle cells with single central nucleus. Like the other two type of muscles (cardiac and skeletal), smooth muscles also have four main functions:
- Contractility-ability to contract. In the case of skeletal muscles it is voluntary, while in cardiac and smooth muscles it is unconscious.
- Excitability-ability to change membrane potential usually by the influence of nervous impulse.
- Extensibility-the capacity to lengthen
- Elasticity-ability to change its length and then return to previous.
This would impact the food chain. The smallest disruption causes drastic changes within an ecosystem.
