Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Population Growth

Population Growth

Population size is dynamic, increasing with birth rates and immigration, and decreasing with death rates and emigration. In ideal conditions with unlimited resources, populations can increase exponentially, which plots as a J-shaped growth rate curve of population size against time. This type of curve is characteristic of newly-introduced invasive species, or populations that have suffered catastrophic declines and are rebounding.

Cloning of Dolly the Sheep

Cloning of Dolly the Sheep

The first successfully cloned mammal was Dolly, a sheep, born on 5th July 1996 at Roslin Institute, Scotland. The cloned sheep was named after the American singer Dolly Parton. Dolly lived for seven years and died of respiratory complications, which is speculated to be due to the actual age of her DNA. Because the DNA in cloned cells belongs to an older individual, the cloned individual’s life expectancy may be affected. Indeed, analysis of Dolly’s DNA revealed shorter...

Nondisjunction

Nondisjunction

Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers. Nondisjunction is common during anaphase I or anaphase II of meiosis. Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold...

Nondisjunction

Nondisjunction

During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.

Oogenesis

Oogenesis

In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...

Testing a Claim about Mean: Known Population SD

Testing a Claim about Mean: Known Population SD

A complete procedure of testing the hypothesis about a population mean is explained here.
Estimating a population mean requires the samples to be distributed normally. The data should be collected from the randomly selected samples having no sampling bias. The sample size needed to be higher than 30, and most importantly, the population standard deviation should be already known.
In most realistic situations, the population standard deviation is often unknown, but in rare circumstances, when it...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Reconstituted phosphatidylserine synthase from Escherichia coli is activated by anionic phospholipids and micelle-forming amphiphiles.

Biochimica et biophysica acta·1999

Same author

Polyunsaturated fatty acid accretion in first- and second-trimester human fetal brain: lack of correlation with levels in paired placental samples.

Biochemical and molecular medicine·1996

Same author

Essential fatty acid status is altered in pregnancies complicated by intrauterine growth retardation.

World review of nutrition and dietetics·1994

Same author

Longitudinal follow-up of growth in children born small for gestational age.

Acta paediatrica (Oslo, Norway : 1992)·1993

Same author

Fetal ponderal index as an instrument for further classification of intra-uterine growth retardation.

Acta obstetricia et gynecologica Scandinavica·1992

Same author

Essential fatty acids in pregnancies complicated by intrauterine growth retardation.

International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics·1991

Search research articles

Related Experiment Video

Updated: Dec 25, 2025

Author Spotlight: Exploring the Long-Term Health Impacts of Intracytoplasmic Sperm Injection on Offspring

Author Spotlight: Exploring the Long-Term Health Impacts of Intracytoplasmic Sperm Injection on Offspring

Published on: May 17, 2024

[Higher order multiple births in Iceland 1982-1998.].

G Vilbergsson, S Haraldsson

|May 15, 2009

Summary

This summary is machine-generated.

Multiple births, including higher-order multiples, have significantly increased in Iceland over 17 years, particularly after the advent of successful in vitro fertilization (IVF) treatments. This trend highlights the impact of assisted reproductive technologies on pregnancy outcomes.

More Related Videos

Generating a Reproducible Model of Mid-Gestational Maternal Immune Activation using PolyI:C to Study Susceptibility and Resilience in Offspring

Generating a Reproducible Model of Mid-Gestational Maternal Immune Activation using PolyI:C to Study Susceptibility and Resilience in Offspring

Published on: August 17, 2022

Trans-inner Cell Mass Injection of Embryonic Stem Cells Leads to Higher Chimerism Rates

Trans-inner Cell Mass Injection of Embryonic Stem Cells Leads to Higher Chimerism Rates

Published on: May 29, 2018

Related Experiment Videos

Last Updated: Dec 25, 2025

Author Spotlight: Exploring the Long-Term Health Impacts of Intracytoplasmic Sperm Injection on Offspring

Author Spotlight: Exploring the Long-Term Health Impacts of Intracytoplasmic Sperm Injection on Offspring

Published on: May 17, 2024

Generating a Reproducible Model of Mid-Gestational Maternal Immune Activation using PolyI:C to Study Susceptibility and Resilience in Offspring

Generating a Reproducible Model of Mid-Gestational Maternal Immune Activation using PolyI:C to Study Susceptibility and Resilience in Offspring

Published on: August 17, 2022

Trans-inner Cell Mass Injection of Embryonic Stem Cells Leads to Higher Chimerism Rates

Trans-inner Cell Mass Injection of Embryonic Stem Cells Leads to Higher Chimerism Rates

Published on: May 29, 2018

Area of Science:

Reproductive Medicine
Perinatology
Public Health

Context:

Rising incidence of multiple births globally due to infertility treatments.
Need to understand trends in specific populations like Iceland.
Icelandic Birth Registry data provides a valuable resource for epidemiological studies.

Purpose:

To investigate the incidence of higher order multiple pregnancies in Iceland from 1982-1998.
To analyze trends in twin and higher order multiple births.
To assess the impact of in vitro fertilization (IVF) on these trends.

Summary:

A total of 73,164 births were analyzed, revealing an increase in both twin and higher order multiple births.
Incidence of twins rose from 1:103 to 1:55, while higher order multiples increased from 1:6127 to 1:1116.
The rise in higher order multiples was more pronounced than for twins, coinciding with advancements in IVF technology.

Impact:

Demonstrates a significant increase in multiple births in Iceland over 17 years.
Highlights the substantial impact of IVF on the incidence of higher order multiples.
Provides data on perinatal mortality, gestational age, and birth weight for higher order multiples, indicating potential risks.