Biology Exam Questions for MBBS Entrance Exams on “Organisms – Post-Fertilisation Events in Sexual Reproduction”.
1. What is the event after zygote formation called?
a) Pre-fertilization
b) Post-fertilization
c) Fertilization
d) Gametogenesis
Answer: c
Clarification: Sexual reproduction is divided into 3 events. Pre-fertilization, fertilization and post-fertilization events. Pre fertilization is the events occurring before fusion of gametes (gametogenesis), fertilization is the fusion of gametes to form zygote and post-fertilization are the events occurring after zygote formation.
2. Zygote divides by ______ to form haploid spores.
a) mitosis
b) meiosis
c) fragmentation
d) sporulation
Answer: b
Clarification: Organisms having haplontic lifecycles, zygote divides by meiosis to form haploid spores that grow into haploid individuals. Formation of zygote forms the vital link, ensuring continuity of the species.
3. What is development of embryo called?
a) Fertilization
b) Syngamy
c) Parthenogenesis
d) Embryogenesis
Answer: d
Clarification: Embryogenesis is the process of embryo formation from a zygote. It undergoes mitosis and cell differentiation in this process. Cell differentiation helps in categorizing cells into specialized tissues.
4. What are animals in which zygote development happens outside the body called?
a) Viviparous
b) Oviparous
c) Reptiles
d) Birds
Answer: b
Clarification: Animals are categorized into 2 types of–oviparous and viviparous. Oviparous animals are those animals in which zygote development takes place outside the body. Reptiles and birds are examples of oviparous animals.
5. What are animals in which zygote formation takes place in the body called?
a) Oviparous
b) Viviparous
c) Humans
d) Whales
Answer: b
Clarification: Animals are categorized into 2 types of–oviparous and viviparous. Viviparous animals are those animals in which zygote development takes place within the body itself. Mammals are a very good example for viviparous reproduction.
6. Oviparous animals lay eggs.
a) True
b) False
Answer: a
Clarification: Since development of oviparous animals takes place outside the body, they develop a calcareous outer shell that provides protection for the zygote. The eggs are laid in a safe place. After a period of incubation, the eggs hatch to give young ones.
7. Chances of survival are more for ______ animals.
a) Terrestrial
b) Oviparous
c) Viviparous
d) Aerial
Answer: c
Clarification: Since zygote development takes place inside the female body, they are in a protected environment. Unlike the oviparous animals, which are vulnerable. The chances of oviparous animals to survive is low.
8. In flowering plants, where is the zygote formed?
a) Ovule
b) Pollen tube
c) Anther
d) Stalk
Answer: a
Clarification: In flowering plants, the zygote is formed in the ovule. The pollen tube is a mode of transportation for the pollens that lay on the stigma, to the ovaries. Anther consists of pollen grains (male gamete).
9. What does the zygote develop into?
a) Embryo
b) Baby
c) Morula
d) Humans
Answer: a
Clarification: Zygote develops into an embryo. It happens through a series of cell division and cell differentiation. In case of flowering plants, the zygote develops into an embryo and the ovule develops into a seed.
10. What is the thick wall developed on a fruit called?
a) Parenchyma
b) Hilum
c) Pleurae
d) Pericarp