Fertilisation in Animals Practice Questions
38 free Fertilisation in Animals practice questions for the Zoology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which of the following best defines external fertilisation in animals?
- A Fusion of gametes inside the female reproductive tract of the parent
- B Fusion of gametes outside the parents' bodies
- C Fusion of gametes within specialized reproductive organs
- D Fusion of gametes only in terrestrial habitats
Correct answer: Fusion of gametes outside the parents' bodies
External fertilisation occurs when male and female gametes fuse outside the body, usually in water. It is common in many aquatic animals like fishes and amphibians.
Which environmental condition is essential for successful external fertilisation?
- A Dry atmosphere
- B Internal gestation
- C Presence of water
- D Thick protective shells
Correct answer: Presence of water
Water is essential for external fertilisation because it allows sperm to swim toward the egg. Without water, gametes would dry out and fail to fuse.
Internal fertilisation is most commonly seen in:
- A Aquatic invertebrates with broadcast spawning
- B Fishes with external spawning
- C Reptiles, birds, and mammals
- D Echinoderms
Correct answer: Reptiles, birds, and mammals
Internal fertilisation is characteristic of reptiles, birds, and mammals. It protects gametes and embryos from environmental hazards.
Which advantage is associated with internal fertilisation?
- A Production of a very large number of gametes
- B Less parental investment
- C Higher survival rate of offspring
- D Dependence on water bodies
Correct answer: Higher survival rate of offspring
Internal fertilisation increases the survival rate of offspring by protecting gametes and embryos. This reduces wastage compared to external fertilisation.
Which animal group typically exhibits external fertilisation?
- A Birds
- B Mammals
- C Amphibians
- D Reptiles
Correct answer: Amphibians
Most amphibians, such as frogs, show external fertilisation. They release gametes into water where fertilisation occurs.
One major disadvantage of external fertilisation is:
- A Low gamete production
- B High parental care
- C High wastage of gametes
- D Embryonic development inside uterus
Correct answer: High wastage of gametes
External fertilisation involves releasing large numbers of gametes, many of which are lost. This leads to high gamete wastage.
In internal fertilisation, fertilisation usually occurs in the:
- A The external aquatic environment
- B The male reproductive system organs
- C Female reproductive tract
- D Cloaca only
Correct answer: Female reproductive tract
In internal fertilisation, sperm enters the female body and fertilisation takes place in the female reproductive tract. This ensures better protection of the zygote.
Which adaptation supports internal fertilisation in terrestrial animals?
- A External spawning
- B Copulatory organs
- C Gelatinous egg coverings
- D Broadcasting of gametes
Correct answer: Copulatory organs
Copulatory organs help in direct transfer of sperm into the female body. This adaptation is essential for internal fertilisation on land.
Why do animals with external fertilisation usually produce a large number of eggs?
- A Eggs are fertilised internally
- B Survival rate of embryos is low
- C Parental care is extensive
- D Embryos develop inside the body
Correct answer: Survival rate of embryos is low
Because many eggs and sperm are lost in the environment, producing a large number increases the chance of successful fertilisation and survival.
Which of the following is a correct match?
- A Birds – External fertilisation
- B Fishes – Internal fertilisation
- C Frogs – External fertilisation
- D Mammals – External fertilisation
Correct answer: Frogs – External fertilisation
Frogs typically show external fertilisation in water. Birds and mammals, on the other hand, exhibit internal fertilisation.
Internal fertilisation reduces dependence on water because:
- A Gametes are released in air
- B Fertilisation occurs inside the body
- C Eggs lack protective coverings
- D Sperm are immobile
Correct answer: Fertilisation occurs inside the body
Since fertilisation occurs inside the female body, internal fertilisation does not require an external aquatic medium. This is advantageous for terrestrial life.
Which statement about external fertilisation is correct?
- A Occurs mostly in fully terrestrial animals with copulation
- B Requires specialized mating organs
- C Involves synchronized gamete release
- D Produces fewer offspring
Correct answer: Involves synchronized gamete release
External fertilisation often involves synchronized release of gametes to increase chances of fusion. This timing is crucial in aquatic environments.
Which factor most strongly favors the evolution of internal fertilisation?
- A Aquatic habitat
- B High gamete mortality
- C Terrestrial life
- D Low parental care
Correct answer: Terrestrial life
Terrestrial life favors internal fertilisation because it prevents desiccation of gametes. It allows reproduction independent of water bodies.
Which of the following animals shows internal fertilisation but lays eggs?
- A Frog
- B Fish
- C Bird
- D Starfish
Correct answer: Bird
Birds show internal fertilisation, but embryonic development occurs in eggs laid outside the body. The eggs have protective shells.
External fertilisation is least likely to occur in:
- A Marine fishes
- B Amphibians
- C Terrestrial mammals
- D Aquatic invertebrates
Correct answer: Terrestrial mammals
Terrestrial mammals rely on internal fertilisation due to land conditions. External fertilisation would expose gametes to desiccation.
Which reproductive strategy usually involves minimal parental care?
- A Internal fertilisation
- B Viviparity
- C External fertilisation
- D Placental development
Correct answer: External fertilisation
External fertilisation often involves little to no parental care. Survival depends largely on the number of offspring produced.
The probability of fertilisation success in external fertilisation is increased by:
- A Low number of gametes
- B Internal gestation
- C Simultaneous release of gametes
- D Thick egg shells
Correct answer: Simultaneous release of gametes
Simultaneous release of gametes ensures that sperm and eggs are present at the same time and place. This increases chances of fertilisation.
Which of the following is NOT a feature of internal fertilisation?
- A Higher chance of fertilisation
- B Reduced gamete wastage
- C Dependence on aquatic medium
- D Protection of zygote
Correct answer: Dependence on aquatic medium
Internal fertilisation does not depend on an aquatic medium. Fertilisation occurs within the female body, offering protection.
Which type of fertilisation generally leads to fewer but well-developed offspring?
- A External fertilisation
- B Broadcast spawning
- C Internal fertilisation
- D Fragmentation
Correct answer: Internal fertilisation
Internal fertilisation usually results in fewer offspring with higher survival rates. Greater protection and parental investment support development.
Why is external fertilisation rare in terrestrial environments?
- A Low oxygen availability
- B Difficulty in gamete transport
- C Risk of gamete desiccation
- D Lack of mating behavior
Correct answer: Risk of gamete desiccation
In terrestrial environments, gametes are at high risk of drying out. This makes external fertilisation inefficient on land.
What is external fertilisation?
- A Fusion of gametes outside the body
- B Fusion of gametes inside the female body
- C Fusion of gametes in the nucleus
- D Fusion of gametes in blood
Correct answer: Fusion of gametes outside the body
External fertilisation occurs when sperm and egg unite outside the body, usually in aquatic environments. It requires a moist medium for gamete survival.
Which environment is most suitable for external fertilisation?
- A Aquatic environment
- B Dry terrestrial habitats
- C Arid desert regions
- D Polar ice regions
Correct answer: Aquatic environment
External fertilisation typically occurs in water because it prevents gametes from drying out. It also facilitates movement of sperm toward eggs.
Which group of animals commonly exhibits external fertilisation?
- A Mammal species
- B Bird species
- C Fish species
- D Reptile species
Correct answer: Fish species
Fish commonly reproduce through external fertilisation. They release eggs and sperm into water where fertilisation occurs.
What is internal fertilisation?
- A Fusion of gametes within the female
- B Fusion of gametes outside the body
- C Fusion of somatic cells in cytoplasm
- D Fusion of DNA strands without gametes
Correct answer: Fusion of gametes within the female
Internal fertilisation occurs when sperm fertilizes the egg within the female reproductive tract. It is common in terrestrial animals.
Which group of animals primarily shows internal fertilisation?
- A Fish
- B Amphibians
- C Mammals
- D Echinoderms
Correct answer: Mammals
Mammals reproduce through internal fertilisation. This allows better protection of developing embryos.
Why do animals with external fertilisation produce a large number of gametes?
- A To increase the chances of fertilisation
- B To increase mutation rate
- C To reduce reproduction
- D To conserve valuable reproductive energy
Correct answer: To increase the chances of fertilisation
External fertilisation has low success rates due to environmental factors. Producing many gametes increases the probability of fertilisation.
Which is an advantage of internal fertilisation?
- A Higher survival of offspring
- B Requires an aquatic medium
- C Provides low parental care
- D Causes significant gamete wastage
Correct answer: Higher survival of offspring
Internal fertilisation protects gametes and embryos, leading to higher survival rates. It reduces dependency on external conditions.
Which is a disadvantage of external fertilisation?
- A High offspring survival rate
- B Low gamete production
- C Provides complete internal protection
- D Low fertilisation success
Correct answer: Low fertilisation success
External fertilisation has a low success rate due to environmental hazards. Many gametes are lost before fertilisation occurs.
Which animal shows internal fertilisation but lays eggs?
- A Fish
- B Frog
- C Starfish
- D Bird
Correct answer: Bird
Birds exhibit internal fertilisation but lay eggs. The embryo develops inside a protective eggshell.
Which reproductive strategy generally involves minimal parental care?
- A Internal fertilisation
- B External fertilisation
- C Viviparity
- D Parental incubation
Correct answer: External fertilisation
External fertilisation usually involves little to no parental care. Offspring are left to develop independently.
Which condition is essential for successful external fertilisation?
- A Dry environment
- B Presence of water
- C High temperature
- D Low oxygen levels
Correct answer: Presence of water
Water is essential to keep gametes viable and allow sperm movement. Without moisture, fertilisation cannot occur externally.
Which of the following is NOT a feature of external fertilisation?
- A Occurs in water
- B High gamete production
- C Direct protection of embryo
- D Low fertilisation success rate
Correct answer: Direct protection of embryo
External fertilisation does not provide direct protection to embryos. Gametes and embryos are exposed to environmental risks.
Which factor favors the evolution of internal fertilisation?
- A Aquatic environment conditions
- B Dry terrestrial conditions
- C Low temperature
- D High humidity
Correct answer: Dry terrestrial conditions
Dry terrestrial conditions favor internal fertilisation as it protects gametes from desiccation. It ensures successful reproduction on land.
Which statement about internal fertilisation is correct?
- A Occurs entirely outside the body
- B Requires water medium
- C Provides protection to gametes
- D Involves many gametes
Correct answer: Provides protection to gametes
Internal fertilisation protects gametes from environmental hazards. It increases the chances of successful fertilisation.
Which type of fertilisation usually results in fewer but more developed offspring?
- A External fertilisation
- B Internal fertilisation
- C Asexual reproduction
- D Binary fission
Correct answer: Internal fertilisation
Internal fertilisation leads to fewer offspring but with better development and survival. Parental care is often higher.
Which organism is most likely to exhibit external fertilisation?
- A Human
- B Frog
- C Bird
- D Dog
Correct answer: Frog
Frogs reproduce through external fertilisation. They release eggs and sperm into water where fertilisation occurs.
Which disadvantage is associated with internal fertilisation?
- A Low survival rate overall
- B High energy investment
- C No protection
- D High gamete wastage
Correct answer: High energy investment
Internal fertilisation requires more energy for mating and development. Fewer offspring are produced compared to external fertilisation.
Which process ensures the meeting of gametes in external fertilisation?
- A Mating
- B Internal transfer
- C Implantation
- D Spawning
Correct answer: Spawning
Spawning involves simultaneous release of eggs and sperm into water. This increases the chances of fertilisation.