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These flashcards cover key concepts in genetics including definitions and principles critical for understanding heredity, inheritance patterns, and the processes involved in meiosis and cell division.

What is a gene?

A sequence of DNA that encodes a protein.

What is a trait?

The physical manifestation of a gene or set of genes.

What distinguishes genotype from phenotype?

Genotype refers to the genetic makeup, while phenotype refers to the observable traits.

What are alleles?

Different versions of the same gene.

Define homozygous.

An organism that has two of the same alleles for a particular gene.

Define heterozygous.

An organism that has two different alleles for a particular gene.

What is the principle of segregation?

The separation of alleles during gamete formation.

What does Mendel's law of independent assortment state?

The alleles of different genes assort independently of one another during gamete formation.

What is a Punnett square used for?

To predict the probability of genotypes and phenotypes in offspring.

How do dominant and recessive alleles interact?

Dominant alleles mask the effect of recessive alleles in a heterozygote.

What happens during meiosis I?

Homologous chromosomes separate into different daughter cells.

What is G1 phase in the cell cycle?

The first gap phase where the cell grows and prepares for DNA synthesis.

What occurs in S phase?

DNA synthesis or replication takes place.

Define transcription in the context of genetics.

The process of making RNA from a DNA template.

What is the F1 generation?

The first generation of offspring from a cross of two parental (P1) plants.

What is the F2 generation?

The second generation of offspring from interbreeding the F1 generation.

What is gamete diversity and how is it affected by crossing over?

The variety of gametes produced due to the exchange of genetic material between homologous chromosomes during meiosis.

What is the expected ratio of phenotypes in the F2 generation?

Typically a 3:1 ratio for dominant to recessive traits.

What do homologous chromosomes contain?

They contain the same genes but may have different alleles.

What is the significance of allele segregation during meiosis?

It ensures that each gamete receives only one allele for each gene.

What does it mean for traits to be true breeding?

Offspring traits are identical to those of their parents.

What does it suggest if a trait reappears in the F2 generation after being masked in the F1?

That the trait is recessive.

What is the genotype for a homozygous dominant individual?

Two dominant alleles, e.g., AA.

What is the genotype for a homozygous recessive individual?

Two recessive alleles, e.g., aa.

What is an example of a dominant trait in Mendel's pea plants?

Yellow seed color.

What is an example of a recessive trait in Mendel's pea plants?

Green seed color.

What is the role of random orientation of homologs during metaphase I?

It leads to independent assortment of alleles.

What is meant by independent assortment in genetics?

The distribution of alleles for different genes occurs independently during gamete formation.

Why is Mendel considered the father of genetics?

He established foundational principles of inheritance through systematic experiments with pea plants.

What discrepancy did Mendel find between the F1 and F2 generations?

The appearance of recessive traits in F2 after being masked in F1.

What is the expected genotype ratio in a monohybrid cross of heterozygotes?

1:2:1 ratio of homozygous dominant, heterozygous, and homozygous recessive.

How can environmental factors influence phenotypes?

They can affect the expression of genes, leading to varied phenotypes.

What role do biochemical processes like cellular respiration play in inheritance?

They provide the energy necessary for cellular processes that regulate gene expression.