Answer:
The nervous system transmits signals between the brain and the rest of the body, including internal organs.
Explanation:
Explanation:
-increases genetic variation
-increases the fitness of a species
Further Explanation:
All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is tightly wound around histones as chromosomes. To produce daughter cells during cell division, the chromosomes (total number of chromosomes (2n)) are copied before the cell splits into two daughter cells. This process is known as mitosis, and occurs in cell division and growth processes. Two new nuclei are formed, along with identical cells. These are the same as the parent cell and the chromosome number (2n) is maintained.
Conversely in meiosis, the number of chromosomes (2n) is halved through meiotic divisions, producing 4 (n) germ cells (sperm or eggs), each containing half the number of chromosomes as its parent cell. During the process of cell division, spontaneous changes within the genome can arise. These mutations are errors occur when copies of the DNA within the cell are made; mutations may range from small changes called single nucleotide polymorphisms, to large scale deletions, and additions which span multiple genes. There are two types:
- somatic: these only occur within certain cells, and arise from environmental factors such as UV light
- hereditary: occur within germ cells of the parent and later the fertilized egg which forms a zygote; these are present within all cells of the new organism.
Like other events, such as crossing over during mitosis and meiosis, mutations lead to increases in genetic variation. This variation refers to the genetic characteristics present within a species. Mutations are maintained within cells, as they form new traits called alleles, which may confer adaptations that increase the fitness of a species, along with ensuring survival by conferring a protective advantage
.
e.g. sickle cell anemia, a disease caused by a mutation, confers protection against the disease malaria.
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Answer;
Opponent process theory
Explanation;
-Opponent process theory suggests that color perception is controlled by the activity of two opponent systems: a blue-yellow mechanism and a red-green mechanism.
-The opponent process theory suggests that the way humans perceive colors is controlled by three opposing systems. We need four unique colors to characterize perception of color: blue, yellow, red, and green. According to this theory, there are three opposing channels in our vision; these are blue vs yellow, red vs green and black vs white.
Answers:
Hormones are chemical messengers....
Endocrine glands secrete hormones...
The pituitary gland plays...
is produced by the adrenal glands...
the gland will produce fewer amounts of the hormone...
produce chemicals called paracrine factors...
blood is called the thyroid.
Steroid hormones are synthesized from cholesterol, while nonsteroid hormones are synthesized from modified amino acids and small peptides. Non-steroid hormones are not lipid-soluble and therefore they need to bind to a receptor on a cell membrane; while steroid hormones can diffuse through the cell membrane.
Explanation:
Hormones are signaling molecules synthesized by glands. The endocrine glands include the adrenal glands, pineal gland, thyroid gland, parathyroid gland, pituitary gland, ovaries, testes, pancreas and hypothalamus. The pituitary gland is an endocrine gland that secretes hormones capable of stimulating the adrenal glands in order to produce steroid hormones. Hormone levels are often modulated by negative feedback, by which high-hormone levels reduce their own production. Paracrine factors (also known as growth and differentiation factors) are proteins that can diffuse across small distances in order to induce responses in neighboring cells. The thyroid gland secretes hormones involved in regulating metabolism and growth. Moreover, the thyroid gland also secretes calcitonin that regulates calcium levels in the blood.
Answer:
Chemicals that are secreted from antigen-presenting cells then activate helper T cells.
Explanation:
