Test: Embryonic Development


25 Questions MCQ Test Biology Class 12 | Test: Embryonic Development


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Attempt Test: Embryonic Development | 25 questions in 25 minutes | Mock test for NEET preparation | Free important questions MCQ to study Biology Class 12 for NEET Exam | Download free PDF with solutions
QUESTION: 1

Three germ layers are formed during which stage of Embryonic development.

Solution:

Gastrulation: Formation of the three primary germ layers occurs during the first two weeks of development. The embryo at this stage is only a few millimeters in length. Gastrulation takes place after cleavage and the formation of the blastula and the primitive streak.

QUESTION: 2

Movement of blastomeres usually seen in which Embryonic stage :-

Solution:

Gastrulation is the process through which the germ layers arise during embryonic development. Morphogenetic motions such as invagination, ingression, and involution characterize this stage.
An epithelial lining of zygote cells pushes inward during the invagination process.
During ingression, epithelial lining cells move to produce mesenchymal cells.
During involution, embryonic tissue moves and folds inward, giving rise to an underlying layer.

QUESTION: 3

The first movements of the foetus and appearance of hair on the head are usually observed during the :-

Solution:

The first movements of the foetus and appearance of hair on the head are usually observed during the fifth month

QUESTION: 4

In which stage rate of cell-division decreases?    

Solution:

Gastrulation is a stage in most animals' embryonic development during which the single-layered blastula is rearranged into a trilaminar ("three-layered") structure known as the gastrula. The ectoderm, mesoderm, and endoderm are the three germ layers. As a result of the full rearrangement of cells that occurs during this phase, cell division decreases at this stage.

QUESTION: 5

Fate map of embryo is prepared in which stage?

Solution:

Fate mapping is a technique for understanding the embryonic origins of diverse tissues in the adult organism by establishing the correspondence between individual cells (or groups of cells) at one stage of development and their progeny at later stages of development. The map depicts an early-stage embryo, known as a blastula, with specific locations highlighted that are known to give rise to specific tissues in the adult organism.

QUESTION: 6

Solid ball of cell produced by repeated cleavage is called

Solution:

After fertilisation, the fertilised ovum is transformed to a zygote. The zygote goes through repeated mitotic divisions, known as cleavage. Cleavage occurs along distinct planes to form a solid mass of cells. Morula is the name given to this solid ball-like structure. Morula is changed into blastula, which has cells arranged in a corner and a cavity produced, which is known as a blastocoel.

QUESTION: 7

Gastrulation is a process

Solution:

In gastrulation differentiation of germ layer occur 

QUESTION: 8

The first indication of division of labour in the blastomeres appear at

Solution:

The gastrula stage is the initial step where cell differentiation occurs. Differentiated cells perform specific functions.
This is why not all cells are programmed to do the same thing. This condition exemplifies the nature of division of labour.
Morphological changes begin to emerge in the embryo, and each cell type begins to recognise one another.

QUESTION: 9

Sexually reproducing multicellular animals start their development from -

Solution:

Sexual reproduction involves the formation and fusing of gametes.
When gametes fuse, a unicellular zygote is formed.
This unicellular zygote is seen in all sexually reproducing species.
A zygote is a critical connection that ensures species continuity from one generation to the next.
Every sexually reproducing organism, including humans, begins life as a single cell–the zygote.

QUESTION: 10

Correct sequence in development is -

Solution:

Fertilization lead to zygote formation followed by Morula, blastocyst and Gastrula 

QUESTION: 11

Preparation of cell differentiation are completed in-

Solution:

Cleavage divides the zygote into many tiny cells that serve as the foundation for later development. At the completion of cleavage, the blastula's little cells begin to move around with relative ease, organising themselves into the patterns required for subsequent development. Surface proteins play a vital role in assisting cells to recognise one another and, as a result, in determining which cells adhere to create tissues. In the blastula stage, the preparation for cell differentiation is accomplished. Gastrulation is the process through which a blastula develops into a three-layered embryo, or gastrula.

QUESTION: 12

What is true for cleavage :-

Solution:

During cleavage, the zygote divides repeatedly, converting the large cytoplasmic mass into a large number of small blastomeres. Because cells are maintained within the zona pellucida, they divide but do not expand in size. Cell size, on the other hand, shrinks during cleavage.

QUESTION: 13

Cleavage start in human in

Solution:

Fertilization occur in fallopian tube in ampulla region at same location Cleavage start 

QUESTION: 14

Type of cleavage in an egg is determined by :    

Solution:

The pattern of embryonic cleavage is influenced by the position of the mitotic spindles as well as the amount and distribution of yolk.

QUESTION: 15

Identical twins will be produced when :

Solution:

One fertilised egg (ovum) divides and produces two offspring with identical genetic material. They are referred to as identical twins. In this situation, a fertilised egg divides into blastomeres, which then separate. The self-contained halves then grow into two newborns with identical genetic information.

QUESTION: 16

Division of human egg is :

Solution:

Because the blastomeres are evenly divided into two cells, the cleavage in the human egg is equal holoblastic.
Cleavage is not asymmetrical because the amount of yolk in the human egg is less since it is microlecithal, hence there is no resistance to cleavage.

QUESTION: 17

The embryo with 8 to 16 blastomeres is called :

Solution:

The zygote undergoes mitotic divisions known as cleavage. Blastomeres are the daughter cells generated during mitotic cleavage of the zygote. Morula is an embryo with 8-16 blastomeres that looks like a mulberry fruit.
Morula divides further to form a blastocyst, which moves towards the uterus.

QUESTION: 18

Function of placenta is :-    

Solution:

The placenta is a cushion-like structure that helps an embryo receive oxygen and nutrition while also removing carbon dioxide and excretory waste products produced by the embryo. It also functions as an endocrine tissue, producing hormones such human chorionic gonadotropin, human placental lactogen, estrogens, progesterone, and relaxin.

QUESTION: 19

Stem cells are found in :-    

Solution:

The blastocyst having inner cell mass has stem cells which are totipotent in nature and undergo division and differentiation.

QUESTION: 20

The first sign of growing foetus may be noticed by :-

Solution:

Growing humans develop their hearts at a very early stage, around the fifth week of gestation, and they begin working, therefore heartbeat detecting is very common and is seen as a growth sign.

QUESTION: 21

During pregnancy only which hormones are secreted in women :-

Solution:

Human placental lactogen, human chorionic gonadotropin and relaxin are produced only in pregnancy.

QUESTION: 22

Placenta contains :-

Solution:

The two main components of placenta are chorionic villi and uterine tissue.

QUESTION: 23

During Implantation, the blastocyst becomes embedded in the which layer of the uterus.

Solution:

Endometrium is part of the uterus which is a layer with blood vessels in which implantation occur

QUESTION: 24

Name the embryonic stage that gets implanted in the uterine wall of a human female. 

Solution:

Implantation is a process in which a developing embryo, moving as a blastocyst through a uterus, makes contact with the uterine wall and remains attached to it until birth. The lining of the uterus (endometrium) prepares for the developing blastocyst to attach to it via many internal changes.

QUESTION: 25

Mammalian placenta originates from :

Solution:

The placenta is developed from the embryo's chorion and allantois as well as the mother's endometrium. Its primary role is to allow chemicals to exchange between the foetus and the mother's body.

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