• Skip to main content
  • Skip to primary sidebar
  • Skip to footer
  • NCERT Solutions
    • NCERT Solutions for Class 12 English Flamingo and Vistas
    • NCERT Solutions for Class 11 English
    • NCERT Solutions for Class 11 Hindi
    • NCERT Solutions for Class 12 Hindi
    • NCERT Books Free Download
  • TS Grewal
    • TS Grewal Class 12 Accountancy Solutions
    • TS Grewal Class 11 Accountancy Solutions
  • CBSE Sample Papers
  • NCERT Exemplar Problems
  • English Grammar
    • Wordfeud Cheat
  • MCQ Questions

CBSE Tuts

CBSE Maths notes, CBSE physics notes, CBSE chemistry notes

What is Fertilization and How Does it Occur in Human Beings ?

Contents

  • 1 Describe the Process of Fertilization in Human Beings
    • 1.1 Development of Embryo
    • 1.2 Differences Between Zygote, Embryo and Foetus

Biochemistry is a field within Biology Topics that explores the chemical processes in living organisms.

Describe the Process of Fertilization in Human Beings

The sperms made in the testes of man are introduced by penis into the woman’s body through vagina. The sperms enter into vagina, pass through the uterus and then go into the oviducts (see Figure). The tail of sperms helps them in moving and reach the oviducts. If at the same time, the ovary of woman releases
Fertilisation in Humans - An Overview 1
an egg (or ovum), then this egg also goes into the oviduct. One of the sperms enters the egg (see Figure). The fusion of sperm with egg is called fertilisation. During fertilisation, the nucleus of sperm fuses with the nucleus of egg cell to form a single nucleus. This results in the formation ola fertilised egg called zygote. Thus, a sperm combines with the egg in the oviduct and fertilises it to form a zygote. The zygote (or fertilised egg) is the beginning of the formation of a new baby (or a new individual).

Development of Embryo

The zygote (or fertilised egg) divides repeatedly to make a ball of hundreds of cells. This is called an embryo. The embryo moves down the oviduct into the uterus. The embryo gets embedded in the soft and thick lining/of the uterus (see Figure). This is called implantation. When the embryo settles down in the uterus, the woman is said to have become pregnant (or said to have conceived). The embryo starts growing
Fertilisation in Humans - An Overview 2
into a baby. The embryo gets food and oxygen from the blood vessels in the lining of the uterus. The cells of embryo begin to form specialised groups that develop into different tissues and organs of the baby. Embryo is an early stage in a developing baby. Thus, an unborn baby at an early stage of development in the uterus is called an embryo. The body features of the unborn baby are not much developed at the embryo stage. The unborn baby remains an embryo in the first eight weeks of pregnancy. A human embryo at 4 to 5 week’s development is shown in Figure. We cannot identify any body features (hands, legs, head, eyes and ears, etc.) of the developing baby in this embryo.

The embryo continues to grow and develop in the uterus to form a baby. The embryo gradually develops body parts such as hands, legs, head, eyes and ears, etc. An unborn baby in the uterus at the stage when all the body parts can be identified, is called a foetus (The word ‘foetus’ is pronounced as ‘fetus’). A human embryo becomes a foetus after about eight weeks of pregnancy. From about eight weeks until birth, the unborn baby is called foetus (see Figure).
Fertilisation in Humans - An Overview 3
It takes about 38 weeks (about nine months) from the fertilisation of egg to the formation of fully developed baby. When the development of the foetus into a baby is complete, the mother gives birth to the baby. The fully formed baby comes out of the mother’s body through vagina. And we say that a baby is born. This is how humans reproduce by giving birth to babies. All of us were born in this way.

Differences Between Zygote, Embryo and Foetus

A zygote forms after fertilisation. A zygote becomes an embryo. And finally, an embryo becomes a foetus. The main differences between zygote, embryo and foetus are given below.

Zygote Embryo Foetus
1. A zygote is formed by the fusion of male and female gametes (sperm and egg) 1. An embryo is formed by the repeated cell division of a zygote. 1. A foetus is formed by the growth and development of an embryo.
2. A zygote is the beginning of the formation of a baby. 2. An embryo is an unborn baby in the uterus in the early stages of development (up to 8 weeks) 2. A foetus is an unborn baby in the uterus in the later stages of development (after 8 weeks till birth).
3. A zygote is a single cell. It is smaller than a full stop (.) 3. An embryo is multicellular. The body features of growing baby in the embryo are not much developed. 3. A foetus is also multicellular. The body features of developing baby (like hands, legs, head, eyes and ears, etc.) can be identified.

Primary Sidebar

NCERT Exemplar problems With Solutions CBSE Previous Year Questions with Solutoins CBSE Sample Papers
  • The Summer Of The Beautiful White Horse Answers
  • Job Application Letter class 12 Samples
  • Science Lab Manual Class 9
  • Letter to The Editor Class 12 Samples
  • Unseen Passage For Class 6 Answers
  • NCERT Solutions for Class 12 Hindi Core
  • Invitation and Replies Class 12 Examples
  • Advertisement Writing Class 11 Examples
  • Lab Manual Class 10 Science

Recent Posts

  • Pressure of a Liquid : Definition, Units and Solved Examples
  • Specific Gravity : Definition, Equation and Solved Examples
  • Omission Exercises for Class 9 CBSE with Answers
  • Stress-Strain Graph : Load-Extension Graph of a String
  • Force Constant of Spring : Series and Parallel Combination
  • Work Done in Stretching a Wire : Energy Density
  • Poisson’s Ratio : Longitudinal and Lateral Strain
  • Mother’s Day Class 11 Questions And Answers NCERT
  • Albert Einstein At School Class 11 Questions And Answers NCERT
  • Elastic Moduli: Young’s Modulus, Shear Modulus, Formula and Units
  • Ranga’s Marriage Class 11 Questions And Answers NCERT
  • The Address Class 11 Questions And Answers NCERT
  • The Summer Of The Beautiful White Horse Class 11 Questions And Answers NCERT
  • Elastic Property of Matter : Some Useful Definitions
  • What is Weightlessness in Artificial Satellite With Example?

Footer

Maths NCERT Solutions

NCERT Solutions for Class 12 Maths
NCERT Solutions for Class 11 Maths
NCERT Solutions for Class 10 Maths
NCERT Solutions for Class 9 Maths
NCERT Solutions for Class 8 Maths
NCERT Solutions for Class 7 Maths
NCERT Solutions for Class 6 Maths

SCIENCE NCERT SOLUTIONS

NCERT Solutions for Class 12 Physics
NCERT Solutions for Class 12 Chemistry
NCERT Solutions for Class 11 Physics
NCERT Solutions for Class 11 Chemistry
NCERT Solutions for Class 10 Science
NCERT Solutions for Class 9 Science
NCERT Solutions for Class 7 Science
MCQ Questions NCERT Solutions
CBSE Sample Papers
NCERT Exemplar Solutions LCM and GCF Calculator
TS Grewal Accountancy Class 12 Solutions
TS Grewal Accountancy Class 11 Solutions