Genetics Test Review: Dominant vs. Recessive, Alleles, Mendel's Laws

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Questions and Answers

How many alleles does a person have for each trait?

One, to maintain genetic stability

Two, one from each parent (correct)

Varies depending on the trait

Three, to ensure genetic diversity

What is the best genotype for a partner if you have Type B blood and want your children to also have Type B blood?

Genotype BO

Genotype BB

Genotype AB (correct)

Genotype OO

Why did Mendel choose pea plants for his experiments?

They are large and easy to observe

They have a short growth period

They can self-fertilize

All of the above (correct)

How does genetic recombination contribute to the uniqueness of an individual?

By shuffling genes to create new combinations Signup and view all the answers

What is the term for the phenomenon where neither allele is dominant over the other?

Codominance Signup and view all the answers

What happens during crossing over in meiosis?

Genetic material is exchanged between homologous chromosomes Signup and view all the answers

What are homologous chromosomes?

Chromosomes that pair up during meiosis Signup and view all the answers

Why do genes need to be arranged in the same order along each homologous chromosome?

To ensure proper gene expression Signup and view all the answers

What is a key advantage of using Punnett Squares in genetics?

Predicting exact outcomes with certainty Signup and view all the answers

Match the genetic concept with its description:

Dominant = Trait that is expressed over recessive trait Recessive = Trait that is masked by dominant trait Homozygous = Having two identical alleles for a gene Heterozygous = Having two different alleles for a gene Signup and view all the answers

Match the genetic term with its explanation involving 'allele':

Law of Segregation = Alleles segregate during gamete formation Law of Independent Assortment = Different genes separate independently during gamete formation Law of Dominance = One allele is dominant and masks the expression of another allele Law of Unit Characters = Genes exist in pairs, with each parent contributing one allele Signup and view all the answers

Match the genetic phenomenon with its definition:

Incomplete Dominance = Neither allele is completely dominant over the other, resulting in a blended phenotype Codominance = Both alleles are fully expressed in the phenotype, showing a combination of traits Crossing Over = Exchange of genetic material between homologous chromosomes during meiosis Genetic Recombination = Creation of new combinations of alleles in offspring through meiosis Signup and view all the answers

Match the feature of pea plants with its importance to Mendel's experiments:

Self-fertilization = Allowed for controlled breeding experiments Pure-breeding lines = Ensured predictable inheritance patterns Visible traits = Facilitated easy observation and recording of results Short generation time = Enabled quick observation of multiple traits across generations Signup and view all the answers

Match the genetic process with its characteristics:

Mitosis = A type of cell division for growth and repair, resulting in two identical daughter cells Meiosis = A type of cell division for reproduction, resulting in four genetically diverse daughter cells Homologous Chromosomes = Pairs of chromosomes that carry genes for the same traits, one from each parent Gene Arrangement = Ensures proper alignment for genetic recombination and variation Signup and view all the answers

Match the blood type scenario with the best genotype for the partner:

Type B blood individual wants Type B children = Partner with Type A blood Signup and view all the answers

Match the parent blood types with their possible offspring genotypes and phenotypes:

Heterozygous A x Homozygous A = <code>AA</code> (Phenotype: Blood type A) Heterozygous A x The stinky one (Heterozygous B) = <code>AB</code> (Phenotype: Blood type AB) Codominant x The recessive one = <code>Ro + Ro</code> (Phenotype: Recessive) Signup and view all the answers

Match the genetic terms with their implications on uniqueness:

Crossing Over = Increases genetic variability by exchanging genetic material between chromosomes Genetic Recombination = Generates unique combinations of alleles in offspring through meiosis Independent Assortment = Leads to new combinations of genes that contribute to individual diversity Homologous Chromosomes = Ensure preservation and shuffling of genetic information during reproduction Signup and view all the answers

Match the genetic laws/rules with their fundamental concepts involving 'allele':

Law of Segregation = Alleles segregate during gamete formation. Law of Independent Assortment = Different genes separate independently during gamete formation. Law of Dominance = One allele is dominant and masks the expression of another allele. Law of Unit Characters = Genes exist in pairs, with each parent contributing one allele. Signup and view all the answers

Study Notes

Dominant and Recessive Traits

A dominant trait will be expressed if an individual has one or two copies of the dominant allele
A recessive trait will only be expressed if an individual has two copies of the recessive allele
Similarities: both dominant and recessive traits are types of alleles, and both have an effect on the phenotype of an individual
Differences: dominant traits mask the effect of recessive traits, recessive traits are only expressed if an individual is homozygous recessive

Homozygous and Heterozygous

Homozygous: an individual has two copies of the same allele (e.g., AA or aa)
Heterozygous: an individual has one copy of each of two different alleles (e.g., Aa)
Similarities: both homozygous and heterozygous individuals have a complete set of genes, both can pass on their genes to offspring
Differences: homozygous individuals have two copies of the same allele, heterozygous individuals have one copy of each of two different alleles

Mendel's Rules and Laws

The Law of Segregation: each pair of alleles separates from each other during gamete formation
The Law of Independent Assortment: alleles for different genes are sorted independently of each other during gamete formation
The Law of Dominance: a dominant allele will be expressed if an individual is heterozygous
The Law of Unity of Heredity: certain traits are determined by discrete units (genes) that are passed on from parents to offspring

Alleles and Traits

Each person has two alleles for each trait, one inherited from each parent
The combination of alleles an individual inherits determines their phenotype for that trait

Pea Plants and Mendel's Experiments

Pea plants are easy to cultivate and produce large numbers of offspring
They have a relatively short generation time, allowing for multiple generations to be studied in a short period
They have a simple genetic makeup, making it easier to study the inheritance of traits

Incomplete Dominance

Occurs when one allele does not completely dominate the other
The phenotype of an individual with incomplete dominance is a mixture of the two parental phenotypes
Example: a cross between a red flower and a white flower produces pink flowers

Codominance

Occurs when both alleles have an equal effect on the phenotype
Example: a cross between a red flower and a white flower produces flowers with red and white stripes

Punnett Squares and Blood Types

A Punnett Square is a tool used to predict the genotypes and phenotypes of offspring
Example: a cross between a heterozygous A and a homozygous A parent produces offspring that are all heterozygous A
Another example: a cross between a heterozygous A and a heterozygous B parent produces offspring with a variety of genotypes and phenotypes

Mitosis and Meiosis

Both are types of cell division, but they have different purposes and occur in different stages of an organism's life cycle
Similarities: both result in daughter cells that are genetically identical to the parent cell, both involve the replication of DNA
Differences: mitosis occurs in somatic cells, meiosis occurs in reproductive cells, meiosis involves crossing over and results in genetically unique daughter cells

Homologous Chromosomes

Homologous chromosomes are pairs of chromosomes that carry the same genes in the same order
Genes need to be arranged in the same order along each homologous chromosome to ensure proper alignment during meiosis

Crossing Over and Genetic Recombination

Crossing over: the exchange of genetic material between homologous chromosomes during meiosis
Genetic recombination: the process of creating new combinations of alleles through crossing over and independent assortment
Genetic recombination contributes to the uniqueness of an individual by increasing genetic variation

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Description

Prepare for your genetics test by reviewing key concepts such as dominant vs. recessive traits, the differences between homozygous and heterozygous genotypes, Mendel's laws explained in terms of alleles, the number of alleles a person has for each trait, and why pea plants were ideal for Mendel's experiments.