The oxygen molecules moves through the nostrils, pharynx, trachea, bronchus, smaller and smaller branches of the bronchial tree, and then into the alveolus.
A peplomer is a glycoprotein spike on a viral capsid or viral envelope. These protrusions will only bind to certain receptors on the host cell; they are essential for both host specificity and viral infectivity.
Answer:
The CTL has specific receptors that can recognize infected or damaged cells.
Explanation:
The cytotoxic T cells (CTL) is a type of white blood cells that specifically helps in destroying virus-infected cells (also damaged cells and cancer cells).
This type of cells has a special receptor called T-cells receptors (TCR) which ones recognize specific antigens (molecule that stimulate the immune systems because are “strange” to them). Virus inside a cell could bind to a special molecule called class I MHC, this molecule moves the virus to the surface of the cell where it can be recognized by a CD8+ specific antigen-receptor of the CTL.
1) The six kingdoms in the six-kingdom system of classification are Archaebacteria, Eubacteria, Protista, Fungi , Plantae and Animalia
2)The two things that make archaebacteria difficult to study are that archaebacteria lived only in these extreme environments and that we don't know how to feed them for studying them
3) Protista is the most heterogeneous kingdom in terms of morphology
4) The difference between kingdom and domain is that the kingdom is one of the five major groups of living organisms while the domain is one of the three taxonomic categories of living organisms above the kingdom level.
Sorry if i’m late to answer it
I hope it’s correct
Answer:
1- Option A) describes an index fossil. Trilobite existed for a short time, but was abundant and lived in many locations.
2- Option B) Continents were once joined and have since drifted apart.
Explanation:
1) Fossils are animal and vegetable rests found in different strata of sedimentary rocks. Sedimentary layers deposit chronologically, so they are used to reflect history. They keep in each layer some of the forms of life that inhabited that area in the past. These fossils turn to be very useful while dating ages. The term Index fossils refer to those fossils that only existed in a given era or geological period during evolution.
Index fossils must:
• Be easily recognizable and distinguishable from all the other fossils
• Have lived in a relatively short geological period
• Present a wide geographic distribution
• Have lived in different sedimentary basins
• Appear in different types of rocks
• Be abundant
<em>A) Trilobite existed for a short time, but was abundant and lived in many locations. </em>The species accomplish the requirements. It is easily recognizable, had a wide geographic distribution, was abundant, and lived for a short time.
2) The tectonic plates theory states that there is a continual movement of the crust. It explains the movement of the different plates and their directions and interactions. The continental drift theory explains how these movements have been taking place since millions of years ago. When continents were together in a unique continent, many species used to inhabit it. When plates started to separate, they took some of these species that got apart by the ocean. Some species were already dead and fossilized, while some other organisms died during continental drift and got fossilized after the divergence. <em>The existence of the same fossils, placed in the same layers and of the same age, suggests that they used to inhabit the same area and died during the same time, meaning that continents were together when they got fossilized. </em>
