What happens if the dividing zygote accidental separates into two? After fertilizations, how long does it take for the blastocyst to arrive in the uterus? What risk does the blastocyst face after it attaches to the uterus? What is gastrulation? What will the lower layer of cells (endoderm) develop into? What will the middle layer of cells (mesoderm) develop into? What will the outer layer of cells (ectoderm) develop into? What does a gene do when it has been turned on? What do the following proteins do? a. Collagen: b. Crystallin: c. Actin and Myosin: d. Hemoglobin: How do cells communicate with each other? How is the Y chromosome different from the X chromosome? Where specifically does the baby get its nutrients from? Do the baby\'s and mother\'s blood ever mix? How old is the fetus when it gains the ability to hear sounds? Why is birth more dangerous for humans than other animals? Solution Q.No 17 A single-celled zygote will undergo multiple rounds of cleavage, or cell division, to be able to produced a ball of cells, called a blastula, accompanied by a fluid-filled cavity to use center, termed as blastocoel. Q.No 18 Blastocyst formation begins about 5 days after fertilization, if your fluid-filled cavity uncovers in the morula, a ball consisting of some dozen cells. The blastocyst possesses a diameter of 0.1-0.2 mm and comprises 200-300 cells following rapid cleavage (cell division). After about 1 day (5–6 days post-fertilization), which it\'s time usually required to contact the uterus, the blastocyst sets out to embed itself into the endometrium of the uterine wall where it may undergo later developmental processes, including gastrulation. Q.No 19 Approximately 5–6 days after fertilization the blastomeres of one\'s blastula set out to undergo cell differentiation and it is structure changes in becoming the blastocyst. With the uterus the zona pellucida of one\'s blastocyst breaks down allowing it to implant straight into the uterine wall approximately 6 days after fertilization. Implantation marks the conclusion of the germinal stage of embryogenesis. Q.No 20 During gastrulation, the blastula folds in on itself to three germ layers, the ectoderm, the mesoderm, and the endoderm, that give rise to the internal structures of one\'s organism. Is it doesn\'t stage of embryo development at which a gastrula is made from your blastula via the inward migration of cells. Q.No 21 The endoderm is among the most germ layers formed during animal embryogenesis. Cells migrating inward across the archenteron form the inner layer of one\'s gastrula, which develops into the endoderm.The endoderm consists at firstly flattened cells, which subsequently become columnar. It forms the epithelial lining of one\'s whole of one\'s digestive tube except an area of the mouth and pharynx along with the terminal an area of the rectum Q.No 22 The mesoderm germ layer forms in the embryos of triploblastic animals.During gastrulation, a few of the cells migrating inward b.

1. What happens if the dividing zygote accidental separates into two? After fertilizations, how
long does it take for the blastocyst to arrive in the uterus? What risk does the blastocyst face
after it attaches to the uterus? What is gastrulation? What will the lower layer of cells
(endoderm) develop into? What will the middle layer of cells (mesoderm) develop into? What
will the outer layer of cells (ectoderm) develop into? What does a gene do when it has been
turned on? What do the following proteins do? a. Collagen: b. Crystallin: c. Actin and Myosin:
d. Hemoglobin: How do cells communicate with each other? How is the Y chromosome
different from the X chromosome? Where specifically does the baby get its nutrients from? Do
the baby's and mother's blood ever mix? How old is the fetus when it gains the ability to hear
sounds? Why is birth more dangerous for humans than other animals?
Solution
Q.No 17
A single-celled zygote will undergo multiple rounds of cleavage, or cell division, to be able to
produced a ball of cells, called a blastula, accompanied by a fluid-filled cavity to use center,
termed as blastocoel.
Q.No 18
Blastocyst formation begins about 5 days after fertilization, if your fluid-filled cavity uncovers in
the morula, a ball consisting of some dozen cells. The blastocyst possesses a diameter of 0.1-0.2
mm and comprises 200-300 cells following rapid cleavage (cell division). After about 1 day (5–6
days post-fertilization), which it's time usually required to contact the uterus, the blastocyst sets
out to embed itself into the endometrium of the uterine wall where it may undergo later
developmental processes, including gastrulation.
Q.No 19
Approximately 5–6 days after fertilization the blastomeres of one's blastula set out to undergo
cell differentiation and it is structure changes in becoming the blastocyst. With the uterus the
zona pellucida of one's blastocyst breaks down allowing it to implant straight into the uterine
wall approximately 6 days after fertilization. Implantation marks the conclusion of the germinal
stage of embryogenesis.
Q.No 20
During gastrulation, the blastula folds in on itself to three germ layers, the ectoderm, the
mesoderm, and the endoderm, that give rise to the internal structures of one's organism. Is it
doesn't stage of embryo development at which a gastrula is made from your blastula via the
inward migration of cells.
Q.No 21

2. The endoderm is among the most germ layers formed during animal embryogenesis. Cells
migrating inward across the archenteron form the inner layer of one's gastrula, which develops
into the endoderm.The endoderm consists at firstly flattened cells, which subsequently become
columnar. It forms the epithelial lining of one's whole of one's digestive tube except an area of
the mouth and pharynx along with the terminal an area of the rectum
Q.No 22
The mesoderm germ layer forms in the embryos of triploblastic animals.During gastrulation, a
few of the cells migrating inward bring about the mesoderm, a different layer between the
endoderm and the ectoderm.Occurance of any mesoderm creates the introduction of a
coelom.Organs formed in a very coelom can freely move, grow, and develop independently of
your physique wall while fluid cushions
Q.No 23
The ectoderm generates the outer layer of one's embryo, but it forms from your embryo's
epiblast. The ectoderm develops straight into the surface ectoderm, neural crest, along with the
neural tube
Q.No 24
A gene is a region of DNA that encodes function.A chromosome has a long strand of DNA
containing many genes.An individual chromosome can get up to 500 million base pairs of DNA
with thousands of genes.A gene can be a locus (or region) of DNA which consists of nucleotides
and may be the molecular unit of heredity.
Q.No 25
a. Collagen – The phrase “collagen” indicates no single protein but a category of structurally
related proteins (at least 29 different types), which constitute the biggest protein element of
connective tissue, and even more generally, the extracellular scaffolding of multicellular
organisms. In vertebrates, they represent about 25-30% of all proteins.
b. Crystallin – Crystallins would be the predominant structural proteins in your lens which have
been evolutionarily related to fret proteins. We were holding first discovered not in the vertebrate
eye lens by Bhat and colleagues in 1989 who found alphaB-crystallin expression in your retina,
heart, skeletal muscles, skin, brain along with other tissues.
c. Actin and myosin – Actin filaments, usually in association with myosin, are responsible for
various types of cell movements. Myosin is a prototype to a molecular motor—a protein that
converts chemical energy available as ATP to mechanical energy, thus generating force and
movement.
d. Haemoglobin - Is it doesn't iron-containing oxygen-transport metalloprotein in the red blood
cells ly vertebrates (with the exception of your fish family Channichthyidae) and also the tissues
of some invertebrates.

3. Q.No 26
Cells communicate through their own individual language of chemical signals. Different
compounds, along the lines of hormones and neurotransmitters, perform like words and phrases,
telling a cell to the environment around it or communicatingmessages
Q.No 27
Males have one Y chromosome and one X chromosome, while females have two X
chromosomes.The Y chromosome features a male-determining gene, SRY, that can cause testes
to develop. The testes produce male hormones which influence body development to produce a
male. The X chromosome contains over 1000 genes, in comparison to 78 genes about the Y
chromosome.
Q.No 28
The yolk sac is definitely a structure that provides nutrients from mom on the embryo prior to
placenta is getting ready to function. ... The umbilical cord isn't formed until about about six
weeks and baby doesn't get nutrients from mother until that point.
Q.No 29
The mother's blood would not normally mix with the baby's blood during her pregnancy, unless
we have seen a procedure (such as amniocentesis or chorionic villus sampling) or vaginal
bleeding. During delivery, however, there may be a strong possibility that several of the baby's
blood cells will enter the mother's bloodstream.
Q.No 30
Around 18 weeks of child bearing, baby starts to check on sound. By 24 week, Baby one is the
most understanding of sound.
Q.No 31
Human births are far more dangerous than your other mammals or simply other primates. The
human brain is 3 to 4 times bigger than an ape's brain. Along with the pelvis is narrower to
allow us to walk upright. A human baby has to have considerable contortions to make it through
the narrow opening.