Phases in Life Cycle MCQ - Practice Questions with Answers

• The life cycle of an organism can be divided into three phases:
  • Juvenile phase
  • Reproductive phase
  • Senescent phase

Juvenile phase:

• It is also called the pre-reproductive phase.
• It is the period of growth that takes place from birth up to reproductive maturity. 
• In plants, it is called the vegetative phase.

Reproductive phase or Maturity Phase:

• During this phase, the organisms reproduce to produce offspring.
• The development and maturation of reproductive organs called puberty occur during this phase.
• In plants, it is marked by the appearance of flowers.
• Plants can be monocarpic or polycarpic.
• Animals can be seasonal breeders or continuous breeders.
• Seasonal breeders reproduce at a particular period of the year, like birds, lizards, etc.
• Continuous breeders continue to breed throughout their sexual maturity.
• The females of placental mammals exhibit cyclical changes in the activities of ovaries and accessory ducts as well as hormones during the reproductive phase.
• It is called the menstrual cycle.
• In non-primate mammals like cows, sheep, rats, deer, dogs, tigers, etc., such cyclical changes during reproduction are called the oestrus cycle.

Senescent Phase:

• It initiates the end of the reproductive phase.
• It is the last phase of the life cycle.