Biology
How does a single-celled fertilized egg grow into an adult in human body?
Answer
The fertilized egg starts developing and by the time it reaches to the uterus from the Oviduct, a small ball of numerous cells is already formed. This is called the embryo. The embryo forms a pit in the wall of the uterus and gets fixed in it. This process is called implantation and it produces the state of pregnancy. The embryo keeps growing in the uterus and specialisation of cells starts, leading to the formation of different parts of the body. This whole process is called differentiation.
By the end of five weeks of pregnancy, the embryo has developed the heart and circulatory system. It is known as foetus now. After two months limbs are also formed. Foetus develops in the uterus for about 280 days. This time period is called gestation. After gestation, birth of the baby happens. The baby is pushed out by the powerful contractions of the muscles of the uterus through the vagina.
Related Questions
Given alongside is a diagram of male reproductive system in humans. Label the parts indicated by numbers 1 to 5, and state their functions.
Draw a neat and labelled diagram showing the reproduction in amoeba. Answer the following questions :
(a) Is reproduction in amoeba of the sexual or asexual kind ?
(b) Name the specific kind of reproduction which occurs in amoeba.
(c) How many offsprings are produced from one division?
(d) What kind of cell division occurs during the reproduction in amoeba?
(e) Give one more example of an organism which reproduces by the same mode of reproduction as that of amoeba.
Draw a neat and labelled diagram of the human female reproductive system. From the diagram, name the following :
(a) The organ where ovum is produced.
(b) The muscular tube situated between the rectum and the urethra.
(c) A hollow, inverted pear-shaped muscular organ found in the pelvic cavity.
(d) A pair of narrow, muscular long ducts extending from each ovary to the upper part of the uterus.
(e) A small lower constricted part of the uterus.
Answer the following questions:
(a) What is budding? Define it.
(b) Is it asexual or sexual mode of reproduction?
(c) Mention one example of a plant and one of an animal that reproduce by budding.
(d) Draw and label the diagram of an animal showing the process of budding.
(e) Write the specific locomotory structures of the animal drawn by you in part (d) above.