Sentences with phrase «when egg and sperm»

When an egg and sperm unite to form an embryo, DNA from the two combine to form the DNA of the embryo.

However, during normal fertilization, when an egg and a sperm fuse, the sperm's mitochondria are destroyed, as the embryo inherits only its mother's mitochondria.

Something seemed to have gone terribly wrong during meiosis, the process that separates chromosomes so that when egg and sperm come together they each contribute half the genetic material to an embryo.

Not exact matches

«Some women with shorter intervals between periods (for example 21 days between each period) experience ovulation (the 24 - hour window when the egg is available for the sperm to fertilize) on day seven or eight, so they are prone to getting pregnant at the end of a long period,» explains Sherry Ross, MD, OB / GYN and women's health expert and author of She - ology.

Is it when the sperm cell is 1 micro nanometer inside the egg cell, and before the original cell begins to replicate?

Is it when the DNA of the sperm cell and the egg cell are about to exchange genetic information?

Now all you need to do is continue that line of reasoning into the arena where / when the sperm and egg have united.

I believe life begins when the sperm and egg unite, and I support quality of life not only in the womb but after birth.

So would you say this is natural when it takes one male sperm and one female egg to produce a fetus.

What science inescapably tells us then, is that each of us as a unique individual human being began when the sperm of our father and the egg of our mother united in what we call the «conception» of a new person.

Implantation Bleeding: This is when you have released an egg and it has been fertilized by a sperm, making a bundle of cells known as a zygote.

When Mommy and Daddy fit together, the sperm had a chance to reach the egg inside Mommy, and that made the baby.»

So much happens during pregnancy that it's basic definition — the period of time when a human being grows from the combination of genetic material from a single egg and sperm — seems almost too simplistic when you say it aloud.

Remember how a woman's egg and a father's sperm meet each other when they have intercourse?

But for us, when an egg is getting ready to divide in an effort to get ready for that sperm to come in and meet it, what happens when the egg has been around for a while, for lack of a better term, the chromosomes get sticky.

I began by describing how mommies have a teeny, tiny egg in their bellies and daddies have a tadpole called sperm, and when they get together, a baby is created instantly.

This is the week when conception takes place (sperm fuse the egg) and zygote divides successively to give rise to your baby some 37 weeks later.

Just as creation requires both egg and sperm, children are happiest when both parents share the power, responsibility, joys and benefits of parenting.

When the same sex intended parents are both female, the eggs from either one or both of the partners will be combined with the sperm from a sperm donor and develop into embryos.

Ovulation is when a mature egg is released from the ovary and pushed down the fallopian tube and is ready to be fertilized by a sperm.

When these fish spawn, eggs and sperm are shed simultaneously into the surrounding water with ovarian fluid being secreted with the eggs.

While getting mammals to undergo true asexual reproduction has thus far been beyond the power of science, researchers are trying to figure out why the union of sperm and egg is so important in mammalian reproduction, when all other domains of life have the ability to reproduce without sex.

The Dawn of the Deed By John A. Long When paleontologist Long spotted a set of tiny bones inside a 380 - million - year - old fossilized fish, he not only discovered the oldest known embryos, he also found the earliest known evidence of animals copulating directly, rather than releasing sperm and eggs to meet in the open sea.

Recombination, or crossing - over, occurs when sperm and egg cells are formed and segments of each chromosome pair are interchanged.

And story number 4: Researchers have found a pair of semi-identical twins that came about when two sperm fertilized a single egg, which then split in two to give rise to two individuals.

Some of the genes in sperm and egg cells have chemicals called methyl molecules that attach to them, a process called methylation; these molecules can either activate or silence a gene when the sperm and egg DNA unite in an embryo.

When an egg or sperm carrying hte gene drive fuses with another egg or sperm, the enzyme and guide RNA are made to cut the gene and start the process over.

When the dancers don't pair or part appropriately it can result in eggs and sperm with the wrong number of chromosomes, a major cause of miscarriage and birth defects.

The two companies that brought the case believe that life begins when a sperm and egg meet.

When the worms smelled a bad environment, the sperm became confused, the sperm moved slower and in a less direct mode to the eggs, which reduced fertility.

«When the sperm enters the egg cell, the densely compacted male chromatin has to be entirely «unpacked» and restructured around protein scaffolds called histones,» explained Sabrina Ladstätter, first author of the study.

In a similar way to how they work in other cells, epigenetic markers push PGCs to their fate during embryonic development, but PGCs are unique because when they develop into sperm and eggs, the epigenetic markers are erased.

Molecules of dsRNA are known to travel between body cells (any cell in the body except germ cells, which make egg or sperm cells) and can silence genes when their sequence matches up with the corresponding section of a cell's DNA.

This contest occurs when a female mates with several males and their numerous sperm compete to fertilize her eggs.

DNA comes in chromosomes, and chromosomes come in matched pairs, and when a body makes a sperm cell or an egg, the two chromosomes in a pair recombine, exchanging large chunks of DNA.

His experiments on sperm and eggs from pigs and cows seem more promising: «When you block proteasomes, you prevent fertilization 100 percent of the time.»

When the female sees those spots, she goes after the male's anal fin as if trying to collect some eggs she dropped, collecting sperm in the process and fertilizing the eggs in her mouth.

A quarter century ago, British physicians Robert Edwards and Patrick Steptoe faced condemnation when they added an egg to sperm in a petri dish and created an embryo that became Louise Brown.

When fresh sperm is used, the biopsy for the sperm retrieval needs to be done the day before or on the same day as egg retrieval from the woman, and this may not be convenient for the couple.

The process begins when a gene for a molecule with a potentially toxic function, like a protein - chopping enzyme, is accidentally duplicated, typically during the formation of egg cells and sperm.

When added to the lower layer, the sperm cell swims through the opening and adheres to, fuses with, and fertilizes the egg.

At 10 p.m., when water is around 24 °C (75 °F), Acropora digitifera corals in the southernmost part of Japan start to release their eggs and sperm, known as gametes, exactly at the same time in a process called synchronized spawning.

When gametes are expelled, sperm are attracted by a chemical cue and swim rapidly to one pole of the egg (bottom left) in order to fertilize it.

When a sperm cell meets an egg cell (the oocyte), it burrows through the thick outer rind surrounding the egg (the zona pellucida), enters the internal cytoplasm of the egg (the ooplasm), and locomotes its male DNA — half of the typical number of chromosomes — to the female half within about three to four hours.

In the current study, three species of hermaphrodite worms — which produce their own sperm and fertilize their own eggs to reproduce — were especially susceptible to sterility and death when mated with males of other species.

This northern coastal seaweed shuns sex when the sea is rough and can carry its gametes — the sperm and eggs — away.

When this mechanism was abolished in female and male germ cells, precursors of eggs and sperm, it had an impact on the flies» fertility.

When these cells were coaxed into forming sperm and used to fertilise eggs, 50 to 60 per cent of the resulting pregnancies led to live births (Science, doi.org/cbxt).

More proof came when the researchers inhibited Udx1 with antibodies or drugs: the egg's membrane did not harden after fertilization, and multiple sperm entered, the team reports in this month's issue of Developmental Cell.

Retrotransposons are normally silenced to prevent harmful mutations from occurring in egg and sperm cells, but are mobilized during certain stages of brain development, when neurons are being produced from dividing stem cells.