MCQ
Which of the following organ is differentiated first during development ?
  • Heart
  • B
    Skin
  • C
    Brain
  • D
    Neural tube

Answer

Correct option: A.
Heart
a
In human beings, after one month of pregnancy, the embryo's heart is formed. By the end of second month of pregnancy limbs and digits are developed. By the end of $12$ weeks (first trimester) most of the major organ systems are formed.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Match the correct pair.

$\begin{array}{|l|l|} \hline Column\;-\;I & Column\;-\;II \\ \hline A.\;Skin & 1.\;Accessory\;digestive\;gland \\ \hline B.\;Pancreas & 2.\;Respiratory\;organ \\ \hline C.\;Genitalia & 3.\;Sensory\;organ \\ \hline D.\;Eye & 4.\;Reproductive\;organ  \\ \hline & 5.\;Excretory\;organ  \\ \hline \end{array}$

 

Azolla is used as a biofertilizer because it
$A$- Adipose tissue is connective tissue

$R$- It serve as a support frame work for epithelium

In man sometime during gametogenesis sex chromosomes are not separated themselves on account of which chromosome number becomes $45, 47$ or $48$. In this condition which of the following genotype and phenotype is correct
Which of the following lubricates ligament or tendons and is an important constituent of synovial fluid of bones?
The segregation of paired hereditary factors that Mendel postulated occurs during
Which of the following is also known as antidiuretic hormone?
Read the following and choose the option with all incorrect statements.
(i) The part of hind brain that contains center which control respiration, cardiovascular reflexes and gastric secretions is medulla.
(ii) Our paired eyes are located in sockets of the skull called orbits.
(iii) The external layer of eye ball is composed of a loose connective tissue and is called the sclera.
(iv) The middle layer of eye ball, choroid, contains many blood vessels and is bluish in colour.
(v) The choroid layer is thin over the posterior 1/3- of the eyeball, but it becomes thick in the anterior part to form the ciliary body.
(vi) The eyeball contains a transparent crystalline lens which is held in place by ligaments attached to ciliary body.
(vii) Retina contains three layers of neural cells- from outside to inside ganglion, bipolar and photoreceptor cells.
(viii) The two types of photoreceptor cells are cones and rods.
(ix) The day light vision also called as photopic vision is function of cones cells.
(x) The twilight vision also called as scotopic vision is function of rods cells
(xi) The cones contain a purplish-red protein called rhodopsin which contain a derivative of vitamin A.
(xii) Photoreceptor cells are not present in eye in the region called blind spot.
During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric change?
A person having blood group $O$ can receive blood of