Download App

Origin and Evolution of Life — BIOLOGY STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceBIOLOGYOrigin and Evolution of Life4 Marks
Question
How were complex organic molecules formed during chemical evolution?
✓

Answer

  1. The primitive broth in which simple organic molecules were suspended, was neutral and free from oxygen.
  2. In this broth polymerisation took place and simple organic molecules aggregated to form new complex organic molecules like polysaccharides, fats, proteins, nucleosides and nucleotides.
  3. Protoproteins were formed by polymerisation of amino acids. These protoproteins later formed proteins.
  4. Formation of protein molecules is considered as landmark in the origin of life. Later the enzymes were formed which accelerated the rate of other chemical reactions.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "Answer the following in detail :" from Origin and Evolution of Life→Origin and Evolution of Life — all question types→BIOLOGY STD 12 Science question papers→Maharashtra Board STD 12 Science question papers→Maharashtra Board question paper generator→

Similar questions

Answer the following questions:
(a) Kabban Park in Bengaluru is having dull flowers with strong fragrance, abundant nectar and edible pollen grains. Identify the type of pollination, the flowers are adapted for.
(b) The process of fruit formation without fertilization is termed as________.
(c) Differentiate between albuminous and exalbuminous seeds.
→
Why is zonation more pronounced at the edges of habitat?
→
(a) Give any two functions of cerebellum.
(b) Write the names of any four motor cranial nerves with their appropriate serial number.
(c) Which hormones stimulate liver for glycogenesis and glucogenolysis?
→
Give detail account of sex-linked inheritance.
→
Complete the flowchart of the process of conduction of nerve impulses.
Application of stimulus on a resting nerve
⇓
Permeability of membrane changes
⇓
______________________________
⇓
Positive ions inside axon increases
⇓
________________________________
⇓
Polarity reverses and depolarisation takes place
⇓
Repolarisation - potassium gates open
⇓
______________________________
⇓
______________________________
⇓
Axoplasm becomes negatively charged and ECF
becomes positive
→
When did Earth originate? Which transformations took place later?
→
Water body ASalinity values B
(1) Streams(a) 340 ppt
(2) Indian Ocean(b) 5 ppt
(3) Hyper saline lagoon(c) 30-35 ppt
(4) Dead sea(d) 100 ppt
→
How is ozone hole formed? OR Give effect of $\text{CFC}$ on ozone shield.
→
Column A (Scientist)Column B (Theory)
(1) Dixon and Joly(a) Starch-sugar                inter conversion
(2) Steward(b) Osmotic absorption theory
(3) Atkins and Pristley(c) Non-osmotic absorption theory
(4) Kramer and Thimann(d) Cohesion tension theory
→
Write full form of
  1. IAA
  2. IBA
  3. NAA
  4. 2,4-D
→