DC Biology 3rd 6 Weeks Extra Credit

Front

What is the main difference between meiosis and mitosis in terms of chromatid separation?

Back

In meiosis, separation of chromatids occurs once, and there are two rounds of cell division, resulting in haploid cells. In mitosis, separation of chromatids occurs once, and there is only one round of cell division, resulting in diploid cells.

Front

What is recombination frequency and how is it measured?

Back

Recombination frequency is the proportion of offspring that exhibit a combination of traits different from either parent, measured in map units, where 1 map unit corresponds to a 1% recombination frequency.

Front

What does it mean for a trait to be recessive?

Back

A recessive trait is one that is expressed only when two copies of the recessive allele are present. In the case of flower color, pink flower color is recessive to blue flower color.

Front

What is a dihybrid cross?

Back

A dihybrid cross is a genetic cross that examines the inheritance of two different traits, typically involving two genes, each with two alleles.

Front

What is the expected phenotypic ratio in a dihybrid cross of heterozygous parents?

Back

The expected phenotypic ratio in a dihybrid cross (AaBb x AaBb) is 9:3:3:1.

Front

What occurs during anaphase I of meiosis?

Back

During anaphase I, homologous chromosomes are separated and move to opposite poles of the cell, while sister chromatids remain attached at their centromeres.

Front

What is the role of cohesion in meiosis?

Back

Cohesion is a protein that holds sister chromatids together at the centromere, ensuring they do not separate until anaphase II.

Front

What is the significance of map units in genetics?

Back

Map units are a measure of genetic distance between genes on a chromosome, indicating how often recombination occurs between them.

Front

How can a compound that prevents homologous chromosome separation affect meiosis?

Back

A compound that prevents homologous chromosome separation can lead to errors in meiosis, resulting in gametes with abnormal chromosome numbers.

Front

What is the expected outcome of self-pollination in a plant with a dominant blue flower trait?

Back

If blue flower color is dominant, self-pollination may produce offspring with a mix of blue and pink flowers, depending on the genotype of the parent.