Lecture 5 BIOA11

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is NOT a disorder screened for in newborns in the U.S.?

Krabbe disease

PKU

Sickle cell

Cystic Fibrosis (correct)

What is the purpose of the Newborn Screening test?

To determine the gender of the baby

To measure the baby's height and weight

To check for vitamin deficiencies

To identify genetic disorders in newborns (correct)

Who is considered the founder of genetics?

Mendel (correct)

Krabbe

Karen Williams

PKU

What is the OMIM database used for?

Identifying genetic disorders in humans Signup and view all the answers

What is the aim for the week mentioned in the text?

To understand the figures, plots, and charts used in scientific literature for human biology Signup and view all the answers

Which of the following accurately describes the process of fertilization in humans?

The sperm and egg fuse to form a zygote Signup and view all the answers

Which statement about genes and chromosomes is correct?

Chromosomes are analogous to words in an instruction manual Signup and view all the answers

What is the purpose of DNA replication?

To produce duplicate DNA molecules Signup and view all the answers

Which of the following best describes a mutant allele?

It functions differently than the original allele Signup and view all the answers

What is the purpose of independent assortment during meiosis?

To ensure the segregation of alleles into different gametes Signup and view all the answers

Which of the following blood types can receive blood from any other blood type?

Type AB Signup and view all the answers

Which of the following blood types can donate blood to any other blood type?

Type O Signup and view all the answers

Which of the following statements about sex-linked traits is true?

Males are more likely to express X-linked traits Signup and view all the answers

Which of the following diseases is more common in males than females?

Red-green colorblindness Signup and view all the answers

In which type of organisms is sex determination based on the incubation temperature of the egg?

Egg-laying reptiles Signup and view all the answers

Which of the following accurately describes the genetic composition of sperm and egg cells?

Sperm and egg cells each have one full set of chromosomes. Signup and view all the answers

What is the total number of possible chromosome combinations in gametes due to independent assortment?

64 trillion Signup and view all the answers

Who is considered the first genetic scientist?

Gregor Mendel Signup and view all the answers

What is the term for the physical traits of an individual?

Phenotype Signup and view all the answers

Which of the following accurately describes carriers of a recessive disease?

Carriers can pass the trait to the next generation. Signup and view all the answers

According to the text, what is the mode of inheritance for a dominant trait?

Autosomal dominant Signup and view all the answers

In a pedigree, what do plain or shaded circles and squares represent?

Affected individuals Signup and view all the answers

What is the probability of Charles and Sarah having a child with Tay Sachs if Sarah's sister has Tay Sachs?

50% Signup and view all the answers

What is the mode of inheritance for a recessive trait in a pedigree?

Autosomal recessive Signup and view all the answers

What process do David and Ruth undergo to produce gametes?

Meiosis Signup and view all the answers

Which of the following is an example of incomplete dominance?

Flower color in snapdragons Signup and view all the answers

How is sickle cell inherited?

Through recessive inheritance Signup and view all the answers

What is the phenotypic ratio resulting from a dihybrid cross between two individuals with genotypes RrYy?

9:3:3:1 Signup and view all the answers

What is the most common recessive disease in Europeans?

Cystic fibrosis Signup and view all the answers

What is the average lifespan of individuals with cystic fibrosis?

40 years Signup and view all the answers

Study Notes

Newborn Screening and Genetics

Newborn screening tests check for various genetic, metabolic, and endocrine disorders to ensure early treatment and intervention.
Disorders typically screened include cystic fibrosis and phenylketonuria, while one specific disorder among the listed options is NOT included.
Founder of genetics: Gregor Mendel, known for his work on pea plant inheritance patterns.

OMIM Database and Genetic Concepts

OMIM stands for Online Mendelian Inheritance in Man and is used to catalog human genes and genetic disorders.
Independent assortment during meiosis ensures genetic diversity by producing unique combinations of chromosomes in gametes.
The total number of possible chromosome combinations in gametes due to independent assortment can reach up to 2^n, where n is the number of chromosome pairs.

Fertilization and Blood Types

Fertilization in humans involves the fusion of sperm and egg, resulting in a zygote.
Blood type AB can receive blood from any other blood type, making it universal recipients, while type O can donate to any blood type, making it universal donors.

Genetics and Inheritance

Genes determine the physical traits (phenotype) of an individual.
A mutant allele represents a variation in the gene sequence, often leading to altered or deficient function.
Carriers of a recessive disease possess one normal allele and one mutant allele and typically do not exhibit symptoms.

Pedigree and Inheritance Predictions

In pedigrees, plain shapes denote unaffected individuals, while shaded shapes represent those with the trait or disorder.
Mode of inheritance for a dominant trait is typically that only one copy of the mutant allele is needed for the trait to manifest and can be traced through generations.
If Sarah's sister has Tay Sachs, the probability of Charles and Sarah having a child with the condition is determined by carrier statuses, usually resulting in a 25% chance if both are carriers.

Sex-linked Traits and Disease Prevalence

Sex-linked traits are often more common in males, resulting from X-linked inheritance patterns.
Sickle cell disease is inherited in an autosomal recessive manner, meaning two copies of the mutant allele are needed for the disease to manifest.

Gamete Formation and Ratios

Gamete production occurs through meiosis, where David and Ruth would undergo this cellular division to create sperm and egg cells.
Incomplete dominance is exemplified by a genetic cross where the phenotype of heterozygotes is intermediate between both homozygotes.
The phenotypic ratio from a dihybrid cross of RrYy typically results in a 9:3:3:1 ratio.

Common Genetic Disorders

Cystic fibrosis is one of the most common recessive disorders in Europeans, affecting respiratory and digestive functions.
Average lifespan of individuals with cystic fibrosis has improved but varies greatly, typically ranging from the late 20s to mid-30s due to advancements in medical care.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the concept of carriers of X-linked recessive traits and how unaffected females can pass on the X-linked allele to their sons. Topics covered include possible types of eggs and the inheritance patterns of unaffected females and carrier females.