viruses

Question 1

viruses are:

Answer 1

non cellular
- simplest biological systems
- aggregates of nucleic acid and protiens

Question 2

viruses cannot (nonliving)

Answer 2

• reproduce outside of host cell
• need host for metabolic activities

Question 3

range of virus sizes (size)

Answer 3

• 5 to 300nm

Question 4

7 characteristics of living things:

Answer 4

• organisation
• metabolism
• growth and development
• homeostasis
• adaptation
• response to stimuli
• reproduction

Question 5

organisation

Answer 5

• being structurally composed of one or more cells (basic unit of life)

Question 6

metabolism

Answer 6

• consumption of energy by converting chemicals into cellular components (anabolism) and decomposing organic matter (catabolism)
• living things require energy to produce phenomena associated with life

Question 7

growth and devlopment

Answer 7

• growth in size: increase size of all parts
• growth in numbers: multiplying and expanding

Question 8

homeostasis

Answer 8

• ability to regulate and maintain a constant internal environment

Question 9

adaptation

Answer 9

• population of living organisms has the ability to change over a period of time in response to the environment, an ability hat is fundamental to process of evolution

Question 10

respond to stimuli

Answer 10

• response that can take on many forms from contraction of a unicellular organism to external chemicals to senses of higher animals
• response often expressed by motion

Question 11

reproduction

Answer 11

• ability to produce new organisms

Question 12

why is virus considered non living

Answer 12

• more non living characteristics than living characteristics

Question 13

living characteristics of virus (3)

Answer 13

• can reproduce at very fast rate but only host cells
• high mutation rate so as to have genetic variation
  -> higher chance of survival in unfavourable environments
• virus direct its host cells to provide energy needed to produce more viral particles

Question 14

non living characteristics of virus (6)

Answer 14

• acellular (no cellular organelles)
  -> does no grow in size
• carry out no metabolism ont heir own
  -> only can with host cell
• posses dna/rna not both
• dont grow or divide,
  -> new viral components are synthesized and assemble within the infected host cell
• does not have the ability to carry out homeostasis since it contains no more than a genome in a protein coat
• does not have the ability to recognise stimuli