Answer:
Un nucleótido esta formado por una molécula de azúcar (ribosa en el ARN o desoxirribosa en el ADN) unido a un grupo de fosfato y a una base nitrogenada.
Explanation:
ADN, ARN son polímeros formados por largas cadenas de nucleótidos.
Las bases utilizadas en el ADN son: adenina, citosina, guanina y timina
En ARN, la base uracilo y ocupa el lugar de la timina.
The second one
One gene for a particular trait
Answer:
The body parts are arranged like spokes on a wheel
Explanation:
Bilateral symmetry is when it is as two halves. And the other two options are not types of symmetries.
The right answer is B.
Cholera vaccination is only recommended for staff who have to intervene with patients in an epidemic situation. In all other cases, effective prevention is provided by good personal hygiene (washing hands) and food.
It is also important to know that this vaccine does not protect permanently: It protects only about 90% within 6 months, then to 50% within 3 years.
Answer:
In gram-negative bacteria, the thin layer of peptidoglycan is surrounded by an outer membrane made of phospholipids, lipopolysaccharides, and proteins. This statement accurately describes specific bacterial cell walls.
Explanation:
The Gram- negative bacteria constitute of an outer membrane which is richly made up of lipopolysaccharides, phopholipids and proteins. The lipopolysaccharides function mainly as a virulence factor and are involved in causing variety of diseases in animals.
Gram- negative bacteria can be seperated from gram- positive bacteria mainly because of the thickness of peptidoglycan and by the presence of the outer membrane of Gram- negative bacteria. The outer membrane is absent in Gram- positive bacteria.