Answer: True
Explanation:
The sunlight is required for the living organism because all the living organism on the earth are either autotrophs or depends on the autotropic organism for their survival.
The green plants perform the process of photosynthesis by trapping sunlight. The other organism depends on the plants for their survival.
Hence, the given statement is true that all the living organism depends directly or indirectly on the sunlight.
"To help foster peace and economic collaboration among European nations" is the one among the following choices given in the question that <span>best describes the purpose of the European Union. The correct option among all the options that are given in the question is the first option or option "A". </span>
Answer:
1. Stimulus
2. Receptors
3. Control center
4. Effector
5. Repeats as long as needed
Explanation:
Lactation during breastfeeding is regulated by positive feedback. As the baby starts sucking, the stimulus (suckling) is sensed by the receptors present in the skin of mammary glands. These signals are carried to the control center, the hypothalamus. Signals are sent to the posterior pituitary to release oxytocin hormone in the blood. The hormone reaches its target organ, mammary glands and stimulates the ejection of milk. Therefore, milk ejection is stimulated by hormone oxytocin in response to suckling.
Since the stimulus, suckling serves to intensify the milk ejection, the regulation is positive feedback. Here, change in a condition triggers a response to intensify the change, not to counteract it.
It a haplont. After fertilization the zygote soon goes through meiosis and produces four haploid flagellated spores (zoo-meiospores), which develop to haploid unicellular individuals. Sometimes, spores are formed from the meiotic products through an additional mitotic division (formation of zoomitospores). This is a type of vegetative propagation. Further, the haploid individuals can go through a mitotic step and become gametes. Gametes fuse (syngamie) together on their turn to form a diploid zygote. The zygote can go to quiescence; it is then called a cystozygote.
or
Haploid vegetative cells (V) perform asexual reproduction under optimal growth conditions. They turn into pregametes (pG) under nitrogen deprivation conditions in darkness. Light induces the formation of gametes (G). Gametes may lose their mating ability and turn to dark-inactivated gametes (dG) upon dark treatment. For simplicity, only the conversion of the plus strain is shown. When gametes of two different mating types are mixed, they will mate and fuse to a quadriflagellated cell that is called early zygote (eZ). The early zygotes convert to mature zygotes (Z) having a thick cell wall after exposure to 15-18 h light followed by 5 days in the dark (Jiang and Stern, 2009). In the absence of any light, zygotes will stay as dormant cells; when light and nitrogen are available, they will undergo meiosis and germinate into four vegetative cells, two plus and two minus.