differentiate between the following : ovipary and vivipary, oestrous cycle and menstrual cycle.
Answers
Answer:
BASIS FOR COMPARISON
■OVIPAROUS ANIMALS
■ VIVIPAROUS ANIMALS
Meaning
■Oviparous are the animals which lay fertilized or an unfertilized egg.
■Viviparous are the animals which give birth to the young ones, and their development occurs inside the female body (mother's womb).
Lay/Give birth
■Oviparous are known to lay eggs, which can be fertilized or unfertilized.
■Viviparous animals directly give birth to the young ones.
Type of fertilization
■It can be internal or external fertilization.
■It is internal fertilization.
Development of zygote
■The development of the embryo takes place outside the embryo.
■The development of the embryo takes place inside the embryo.
Nutrients to the developing embryo
■The embryo receives the nutrients from the egg yolk.
■The embryo receives the nutrients from the mother.
Survival chances
■Less chances of survival, as the eggs are laid in an open environment.
■More chances of survival, as proper protection and nutrition, is provided to the embryo inside the mother's womb.
Examples
■Insects, amphibians, fish, reptiles, birds.
■Mammals like cats, dogs, humans, elephants, lions, tigers, etc.
Menstrual Cycle:
1. It occurs in primates (monkeys, apes and human beings) only.
2. This cycle consists of menstrual phase, proliferative phase and the secretory phase.
3. Blood flows in the last few days of this cycle.
4. The broken endometrium is passed out during menstruation.
5. Sex urge is not increased during menstruation.
6. Female does not permit copulation during menstrual phase of the cycle.
Oestrous Cycle:
1. It occurs in non-primates such as cows, dogs, etc.
2. It consists of a short period of oestrous or heat (e.g., 12-24 hours in cow) followed by anoestrous or passive period.
3. Blood does flow into in this cycle.
4. The broken endometrium is reabsorbed.
5. Sex urge is increased during oestrous period.
6. Female permits copulation only during oestrous period.