1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
12345 [234]
3 years ago
8

1. What was some early evidence of the existence of viruses? Why were they difficult to study?

Biology
1 answer:
kogti [31]3 years ago
5 0

Answer:

Answer No 1:

The earliest evidence for the occurrence of viruses was the discovery of an infectious agent in the sap of a tobacco plant. Experiments were set with different filters from which bacteria could pass but viruses being even smaller than bacteria could not pass.

Viruses were difficult to study because they are very small and couldn't be seen even under a microscope.

Answer No 2:

Wendell Stanley made his studies on the tobacco mosaic virus (TMV). Wendell Stanley developed techniques and crystallized this virus. At that time, it was known that even a very simple cell does not undergo crytallization. Hence, Wendell Stanley got to known that this structure is some infectious agent which has the ability  of crystallization.

Answer No 3:

The four forms of viral genomes are:

  • double-stranded DNA
  • single-stranded DNA
  • double-stranded RNA
  • single-stranded  RNA.

Answer No 4:

The capsid can be described as proteins which make up a shell to enclose the genome of a virus. Capsomeres can be described as the protein sub-units from which a capsid is made. The shapes of a capsid can be characterized into

  • rod-shaped: helical viruses, or inside spherical viruses .
  • icosohedral: icosohedral viruses or the heads of bacteriophages.

Answer No 5:

The components of a viral envelope involve phospholipids and membrane proteins and proteins and glycoproteins. The phospholipids and membrane proteins are derived from the host cell.  The proteins and glycoproteins are of the viral origin.

You might be interested in
Which fungi has a positive and negative mating strands
Inga [223]

Answer:

yeasts and hyphae

Explanation:

3 0
3 years ago
Define virus and virion, and describe the parts of a virion.
leva [86]

Answer:

A virus is a tiny infectious biological agent that can only replicate or duplicate inside the host cell. These infectious agents can infect all different types of living organisms ranging from animals and plants to microorganisms and archaea and bacteria.

Virions are ineffective particle or form of the virus outside of the host cell, with RNA or DNA and a protein capsid.

The main role of these infectious agent virions is to transfer the DNA or RNA genome from itself to the cell of host and expressed the gene which means produce proteins from the genome transferred to the host cell.

6 0
3 years ago
Which organelle fills the cell, holds organelles, and is the place for most of the metabolic activity in the cell occur?
Andru [333]

A. Cytoplasm


(The Nucleus is the control, site of DNA)

Cell wall is in plant cells, giving stability and protecting the cell from rupturing. DNA is stored in the Nucleus, not a organelle.


The answer is Cytoplasm, C.

8 0
3 years ago
Read 2 more answers
Gregor mendel concluyo que cada guisante tiene dos unidades para cada rasgo y cada gameto cotiene una unidad . Las unidades de m
fredd [130]

Answer:

Las unidades de Mendel se conocen ahora como GENES

Explanation:

Durante sus experimentos, Mendel demostró que las características de las plantas de guisante (por ejemplo color de la flor, color de la semilla, forma de la semilla, altura de la planta, etcétera) eran heredadas, y denominó "elementos" a las unidades portadoras de dichas características. Es decir que cada elemento o unidad discreta, era el responsable de que la planta exprese una u otra característica. Estableció que estos elementos se redistribuían independientemente uno de otro, generación tras generación. Con el paso del tiempo y el avance de las investigaciones, estas unidades o elementos fueron denominados <em>Genes</em>.      

5 0
3 years ago
Which blood type can be given to anyone?<br><br> A : A<br> B : B<br> C : AB<br> D : O
True [87]
Blood type O can be given to anyone.
5 0
3 years ago
Other questions:
  • In the 1800s, how did Darwin explain the origin of species?
    13·2 answers
  • ______ waves cause the most damage during an earthquake.
    12·1 answer
  • What determines how many covalent bonds two atoms can make?
    12·1 answer
  • Which best describes the purpose of bar graphs?
    11·2 answers
  • A dichotomous key helps identify organisms through its
    10·1 answer
  • WILL GIVE BRAINLIEST
    9·1 answer
  • Which part of the neuron sends messages to other neurons by receiving an action potential and then opening
    6·1 answer
  • When a single species, such as ancestor of the Galapagos finches, has evolved into several different forms that live in differen
    5·1 answer
  • What are the letters of the anticodon that should be in the three boxes labeled “Question #18” in the drawing below?
    5·1 answer
  • During meiosis i, homologous chromosomes undergo crossing over while they are side-by-side in an event called ______.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!