THE BEGINNING OF HUMAN LIFE
Human life is
the sum of many individual cells organized in specific ways. It begins with
fertilization, when the nucleus of a sperm cell combines with nucleus of an
ovum. The result is a zygote, a single cell that contains hereditary (genetic)
material from both parents: 23 pairs of chromosomes, each of which consists of
a single, long, thin, twisting bit of DNA.
DNA is an amazingly complex chain of chemicals
that is uniquely different in each and every living thing. This is because the
genes that we inherit from our parents are incorporated into the DNA molecule
that makes up each chromosome. How the zygote develops is determined by the
unique combination of genes that are in its DNA. It’s as if the genes carry
with them a detailed genetic “blueprint” that controls what happens at every
stage of the new organism’s development.
WORDLIST
- sum= άθροισμα
- cells= κύτταρα
- fertilization= γονιμοποίηση
- nucleus= νουκλεοτίδιο
- combine with = συνδέομαι με
- ovum= ωάριο
- zygote= ζυγωτό (αρχικό κύτταρο ενός μωρού)
- hereditary = κληρονομικά
- chromosomes = χρωμοσώματα
- determined = καθορισμένος
- DNA = δεσοξυριβονουκλεϊκό οξυ
- complex = περίπλοκο
- genes = γονίδια
- inherit = κληρονομώ
- incorporated into = ενσωματώνομαι σε
- molecule = μόριο
- combination = συνδυασμός
- stage = στάδιο
- consists of = αποτελείται από
EXERCISE
Match the bold words of the text with their meanings. The pictures will help you!
female reproductive cell= ________________
baby "starter" cell = ________________
conception/ start of new life = ________________
central part of cell = ________________
inherited/ passed on = ________________
subunits of DNA that contain inherited characteristics = ________________
LISTENING PRACTISE
Watch the video carefully and complete the text (1-3 words):
Fertilization
is the epic story of a single sperm facing (1) ___________ __________
to unite with an egg and form a new human life.
During the
sexual process (2) _____________ sperms enter into the vagina. Thousand sperms die,
but many survive due to the (3) _____________ surrounding them.
Inside the
uterus, (4) ______________ _______________ assist the sperms on their journey to
reach the egg.
Chemicals
in the reproductive track cause changes to the sperms´ brains and they become (5) ____________ and (6) ___________ to their
destination.
When the
sperm enters the outer cover of the egg, (7) ____________ _________ are released.
Inside the
egg, the tightly packed (8) _________________ _____________ spreads out, creating
the main pronuclear.
The genetic
material reforms into (9) _____________ __________________ . The combination of
these chromosomes determines the (10) ______________ , the hair and the (11) ___________ color
and many other characteristics.
The (12) ______________ is the beginning of a new human being.
* Find the answers in my official website http://stelladelina.byethost5.com or in my facebook page
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