Answer:
CD40L
Explanation:
The CD40 ligand (CD40L) protein is a transmembrane glycoprotein which is expressed on activated T cells and belongs to the tumor necrosis factor (TNF) superfamily. The hyper IgM syndrome is caused by mutations in the CD40L gene, where the defective protein can no longer bind CD40 on antigen-presenting cells. The X-linked Hyper IgM syndrome is characterized by abnormal levels of immunoglobulins, i.e., low levels of IgG and IgA, and increased/normal levels of IgM. Because CD40L gene is located on the X chromosome, this disorder is observed much more frequently in males than in females.
Light is an example of an abiotic factor. It is also the major energy source.
Like all other reptiles, birds have scales. Also, birds lay eggs like other reptiles.
Answer:
Phenotypes:
Aa with a frequency of 2
aa with a frequency of 2
The children have equal chances of having aa or Aa
<h2>Neural crest </h2>
Explanation:
The neural crest likely forms: neurons and glia of the peripheral nervous system
- The neural crest are bilaterally paired strips of cells arising in the ectoderm at the margins of the neural tube
- In the body region, neural crest cells also contribute the peripheral nervous system (both neurons and glia) consisting of sensory ganglia (dorsal root ganglia), sympathetic and parasympathetic ganglia and neural plexuses within specific tissues/organs
- The nervous system is made up of specialized cells which includes nerve cells (or neurons) and glial cells (or glia)
- Neurons are the basic functional units of the nervous system, and they generate electrical signals called action potentials, which allow them to quickly transmit information over long distances
- Glia are also essential to nervous system function, but they work mostly by supporting the neurons
