Answer:
The Alvarez hypothesis posits that the mass extinction of the dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth. Prior to 2013, it was commonly cited as having happened about 65 million years ago, but Renne and colleagues (2013) gave an updated value of 66 million years.[1] Evidence indicates that the asteroid fell in the Yucatán Peninsula, at Chicxulub, Mexico. The hypothesis is named after the father-and-son team of scientists Luis and Walter Alvarez, who first suggested it in 1980. Shortly afterwards, and independently, the same was suggested by Dutch paleontologist Jan Smit
Explanation:
it was on wiki
To raise the defense, the body must first recognize the pathogen or whatever this attacker. <span>There are two types of immune response: innate and adaptive,the Adaptive immune response is much more efficient because it is more specific.
</span>
hope this helps!
Similarities:
Both involve ion movement. Both use ion channels to move ions across the cell membrane, in or out of the cell.
Differences:
Passive Transport (or Diffusion) moves ions from high concentration to low, using no metabolic energy. Active Transport moves ions from low concentration to high, using metabolic energy in the form of ATP. Active Transport uses an ion pump (or Sodium/Potassium pump) to move 3 sodium ions out of the cell and 2 potassium ions in to the cell through the energy of 1 ATP molecule.
In active transport particles move against a concentration gradient and therefore require energy which must be supplied by the cell. Carrier proteins that are found in the cell membrane of cells use energy to transport molecules or ions across the membrane, against the concentration gradient.
Passive transport is a naturally-occurring phenomenon and does not require the cell to exert any of its energy to accomplish the movement. In passive transport, substances move from an area of higher concentration to an area of lower concentration.
Answer:
What is Tissue
Explanation:
A tissue is a group of many similar cells (though sometimes composed of a few related types) that work together to perform a specific function. An organ is an anatomically distinct structure of the body composed of two or more tissue types. Each organ performs one or more specific physiological functions.
Answer:
c, sickle cell anemia
Explanation:
When you are conceived you (generally) receive one set of chromosomes from your mom and one from your dad. Recessive diseases mean that you must receive 2 copies of the mutated gene (disease gene) to express the disease (one from mom and one from dad). Dominant means that you only need one copy of the mutated gene to express the disease.
Sickle cell anemia is a disease caused by a mutation in the hemoglobin-Beta gene found on chromosome 11. The mutation is on an autosome (not a sex chromosome). You need two copies of the bad gene in order to express it.
