Biological Foundations, Genetics, Prenatal Development, and Birth

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Questions and Answers

What is the primary role of DNA in genetics?

To regulate body temperature

To provide energy for cells

To store genetic information and direct cell activities (correct)

To produce nutrients for the body

During which stage of prenatal development does the blastocyst form?

Foetal stage

Birth stage

Embryonic stage

Germinal stage (correct)

Which process is responsible for creating gametes with half the number of chromosomes?

Fertilisation

Cross-over

Mitosis

Meiosis (correct)

What is the significance of the SRY gene in prenatal development?

It triggers the development of male sex organs Signup and view all the answers

Which of the following is a recessive genetic disorder?

Cystic fibrosis Signup and view all the answers

How do polygenic traits differ from single-gene traits?

Polygenic traits are influenced by multiple genes and environmental factors Signup and view all the answers

What is the primary focus of genetic counselling?

To assess the risk of genetic disorders and guide parental decision-making Signup and view all the answers

Which chromosomal disorder is associated with an extra twenty-first chromosome?

Down syndrome Signup and view all the answers

What is the purpose of amniocentesis in prenatal diagnosis?

To detect chromosomal abnormalities in the foetus Signup and view all the answers

In the context of genetics, what does the term 'range of reaction' refer to?

The range of possible phenotypes based on genetic and environmental interactions Signup and view all the answers

How do dominant gene disorders differ from recessive gene disorders?

Dominant disorders manifest even if only one parent passes on the gene Signup and view all the answers

What is the role of the placenta during prenatal development?

To facilitate the exchange of nutrients and waste between mother and foetus Signup and view all the answers

Which prenatal diagnostic technique carries the lowest risk of miscarriage?

Ultrasound Signup and view all the answers

What is an example of a sex-linked recessive trait?

Haemophilia Signup and view all the answers

What does the term 'genomic imprinting' refer to in genetics?

The differential expression of a gene depending on whether it is inherited from the mother or father Signup and view all the answers

Study Notes

Genetic Information and Development

DNA stores genetic information, directing cellular activities and functioning as the blueprint for life.
The blastocyst forms during the germinal stage of prenatal development, marking successful implantation into the uterine wall.

Gamete Formation

Meiosis is the process that creates gametes (sperm and eggs) with half the normal number of chromosomes, essential for sexual reproduction.

SRY Gene Importance

The SRY gene is crucial in prenatal development as it triggers the formation of male sex organs.

Genetic Disorders

Cystic fibrosis is a recessive genetic disorder, requiring both copies of the gene to be mutated for the disease to manifest.
Polygenic traits are influenced by multiple genes and environmental factors, contrasting with single-gene traits that arise from one gene.

Genetic Counseling

The primary focus of genetic counseling is assessing the risk of genetic disorders, aiding parental decision-making without offering cures.

Chromosomal Disorders

Down syndrome is associated with the presence of an extra twenty-first chromosome, leading to various physical and cognitive challenges.

Prenatal Diagnostic Techniques

Amniocentesis is used to detect chromosomal abnormalities in the fetus and carries a higher miscarriage risk compared to ultrasound, which has the lowest risk.

Understanding Genetic Traits

The term "range of reaction" describes potential phenotypes influenced by genetic and environmental interactions.
Dominant gene disorders manifest with just one copy of the mutated gene from either parent, differing from recessive disorders which require both copies to be affected.

Role of the Placenta

The placenta serves as a vital organ that facilitates nutrient and waste exchange between the mother and fetus, also producing hormones needed for fetal growth.

Prenatal Techniques and Traits

Ultrasound is the diagnostic technique with the lowest risk of miscarriage, used primarily for monitoring fetal development.
Haemophilia is an example of a sex-linked recessive trait, often associated with males due to its inheritance pattern.

Genomic Imprinting

Genomic imprinting refers to the differential expression of a gene based on whether it is inherited from the mother or father, impacting development and phenotype.

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Description

Test your knowledge on the fundamental concepts of genetics, including DNA's role, prenatal development stages, and gamete formation. This quiz covers essential topics that are pivotal for understanding heredity and biological processes.