The first movements of the fetus, known as quickening, and the appearance of hair on its head are typically observed during the 5th month of gestation.
Around the 5th month of pregnancy, the fetus's musculoskeletal system develops sufficiently for it to start making noticeable movements. This is often described as fluttering or gentle flutters felt by the mother. Additionally, hair begins to grow on the fetus's head during this time.
Therefore, the correct answer is (D) 5th month.
The correct answer is:
Option 4: 5th month
During the 5th month of gestation, the following key developmental milestones occur:
The first movements of the fetus (also called quickening) can be felt by the mother.
Hair begins to appear on the fetus's head.
The fetus develops more distinct facial features and continues to grow in size.
The other options are incorrect because:
1st month (Option 2): The embryo is still in early stages of development, and organ formation begins.
4th month (Option 3): Some movements may start internally, but they are usually not strong enough for the mother to feel.
8th month (Option 1): By this time, the fetus is fully developed, with well-defined features and significant movement, but the first movements have already occurred earlier.
Thus, the first fetal movements and the appearance of hair on the head are observed in the 5th month of gestation.
In angiosperm, the haploid, diploid and triploid structures of a fertilized embryo sac sequentially are:
Column-I | Column-II | ||
---|---|---|---|
(i) | First month | (a) | Separation of eye lids |
(ii) | Second month | (b) | Hairs on head |
(iii) | Fifth month | (c) | Heart |
(iv) | Six month | (d) | Limbs & digits |
A block of certain mass is placed on a rough floor. The coefficients of static and kinetic friction between the block and the floor are 0.4 and 0.25 respectively. A constant horizontal force \( F = 20 \, \text{N} \) acts on it so that the velocity of the block varies with time according to the following graph. The mass of the block is nearly (Take \( g = 10 \, \text{m/s}^2 \)):
A wooden block of mass M lies on a rough floor. Another wooden block of the same mass is hanging from the point O through strings as shown in the figure. To achieve equilibrium, the coefficient of static friction between the block on the floor and the floor itself is
The circuit shown in the figure contains two ideal diodes \( D_1 \) and \( D_2 \). If a cell of emf 3V and negligible internal resistance is connected as shown, then the current through \( 70 \, \Omega \) resistance (in amperes) is: