Answer:
Self-antigens are not recognized and attacked by the T cells.
Explanation:
In immunology, the antigens are those substances which are bound by the antibodies. The antigens can be originated from within the bodies, known as self antigens or from outside the body, known as non-self antigens. The immune system identifies and attacks non-self invaders or the foreign harmful objects present in the body. It does not attack the self-antigens under the normal conditions. This is due to the negative selection of T cells of the thymus.
Answer:
The correct answer is D: "<em>Apes have a Y-5 pattern of cusps, whereas Old World monkeys have a bilophodont pattern</em>".
Explanation:
Apes and old world monkeys only have four kinds of teeth: <em>two incisors, one canine, two premolars, and three molars</em>. This dental formula is 2.1.2.3.
The old world monkeys characterize for having molars with four cusps joined by ridges. They have bilophodont teeth with better crushing, shearing and wearing capabilities than apes.
Apes´molars have 5 cusps, a Y-shaped space between those raised points, and no transverse lophs. These characteristics are known as the Y-5 pattern.
Answer:
The relationship between Proteins and Nucleic acids is that both find their application in the gene expression process of the living body. During the gene expression in every living cell of any organism, it is seen that the nucleic acids code for amino acids to create proteins
(D) Both perform photosynthesis is the observation that led researchers to propose that chloroplasts evolved from cyanobacteria.
Chloroplasts is the area where photosynthesis takes place. It is a green organelle in a plant cell. Pigments called the chloros in a chlorophyll are needed for the photosynthesis.
Cyanobacteria or blue-gree algae contains a blue photosynthetic pigment and a chlorophyll for photosynthesis.
Answer:
Ribose
Explanation:
DNA is a large molecule, a type of nucleic acid which store and act as a genetic material of the cell. DNA molecule is formed by the repeating monomer units called nucleotides.
Each nucleotide is made up of three subunits as:
1. 5-C sugar: De-oxyribose formed by the removal of oxygen group from 2' OH group of ribose. Ribose is the sugar molecule present in RNA nucleic acid.
2. Phosphate group (PO₄³⁻)
3. Nitrogenous bases: adenine, guanine, adenine and cytosine.
Thus, ribose is the correct answer.
