Answer:
smooth endoplasmic reticulum
Explanation:
Smooth endoplasmic reticulum differs from the rough endoplasmic reticulum in not having ribosomes on its surface. The smooth endoplasmic reticulum (SER) extends from the rough ER and forms a network of membrane tubules. The function of the smooth ER is to serve as a site for the synthesis of lipids, fatty acids, and steroids such as estrogens and testosterone.
Enzymes for the synthesis of these diverse biomolecules are present in smooth ER. The smooth ER present in the muscle cells is called the sarcoplasmic reticulum. It stores the calcium ions which are released into the sarcoplasm of muscle cells during muscle contraction.
Answer:
Since a species' chromosome count doesn't change from generation to generation, meiosis requires that the number of chromosomes in germ cells be cut in half. Meiosis, unlike mitosis, achieves this accomplishment by requiring a single round of DNA replication followed by two rounds of cell division.
Answer:
Protosomes
Explanation:
Protosome is a multicellular organism whose mouth grows before the anus from a primary embryonic opening which includesphyla mollusk, arthropod or annelid. Protosomes are developed by spiral cleavage during embryo development.
Protosome animals have bilateral symmetry and three germ layers. Some of the examples of protostomes are snails and slugs (mollusk), earthworms (annelids), and spiders, lobsters, barnacles (arthropods).
Hence, the correct answer is Protosomes .
Answer:
The answers are c)are the most reinforcing, generate the greatest immediate sensual appeal, and produce the most powerful psychological dependence.
Explanation:
Like all psychoactive substances, amphetamines affect the central nervous system and have stimulating effects (empathy, sensuality, confusion, etc.), producing an alert state along with various reactions in perception. Some individuals also report optical and auditory illusions. On many occasions this is also favored by the existence of intense visual and auditory stimuli, as happens for example at parties. However, most of these desired effects have tolerance with repeated doses of the same substances and even cross tolerance with doses of other substances. With the appearance of this tolerance other effects appear such as aggressiveness, anxiety symptoms, panic attacks, etc.
Among the medical complications related to the use of these substances, acute neurological complications, seizures and cerebrovascular diseases stand out.
Answer:
Changes in gene expression
Explanation:
This phenomenon is the result of changes in gene expression. That means, how the information in the DNA is used by the cell. The genes that are active in the cells of the brain will be very different from the genes that are active in the cells of the bone marrow.
These patterns of gene expression are different for each cell, and dictate the identity of that cell. Gene expression patterns are controlled by a variety of factors in the cell that allow tissue-specific expression, such a transcription factors.
This can also be facilitated by another layer of regulation called epigenetics, which literally means "on top of" genetics, and refers to modifications of DNA (and the proteins around it), that can reflect and influence the activity of the genes within.
