Eukaryote Chromosomes and Karyotypes

Eukaryotic chromosomes come in pairs, also known as homologues.

How many chromosomes do normal humans have?

Each chromosome in a pair comes from the same parent.

Autosomes are found in both males and females.

How many pairs of autosomes are present in humans?

Autosomes in a pair are not homologous.

Sex chromosomes determine an individual's gender.

The X and Y chromosomes are homologous.

The X chromosome is smaller than the Y chromosome.

The Y chromosome carries a large number of genes.

In humans and mammals, females have XX chromosomes and males have XY chromosomes.

What is a karyotype?

A karyotype is a complete set of chromosomes from a cell, including their size, number, and shape.

The goal of cell division is to equally partition two or more identical copies of genetic material between two daughter cells.

Prokaryotes are comparatively simple, having only one chromosome, which makes dividing chromosomes relatively easy.

Eukaryotes, with their longer DNA and multiple chromosomes, find it easier to sort chromosomes during division than prokaryotes do.

Mitosis is a complex process that ensures each daughter cell ends up with the same number and type of chromosomes as the parent cell.

Prokaryotic cell division is required for both development and reproduction.

In eukaryotic cells, chromosomes are found in the cytoplasm, not the nucleus.

Chromosomes are tightly packaged DNA and are only found during cell division.

Chromatin is unwound DNA and is found throughout interphase.

DNA is not used for macromolecule synthesis during chromosome formation.

DNA is being used for macromolecule synthesis during interphase, when DNA exists as chromatin.

Chromosomes are formed through replication and not by the joining of existing chromatids.

Sister chromatids are identical copies of DNA.

Chromosomes are mainly composed of protein.

A gene is a discrete heritable unit that carries traits.

Alleles are different versions of a gene.

Alleles can only differ by one or a few nucleotides.

Different alleles always code for different phenotypes.

A chromatid is considered a chromatid as long as it is associated with a sister chromatid at the centromere.

When sister chromatids separate after metaphase, they become two different chromosomes.

The eukaryotic cell cycle includes interphase and mitosis.

Interphase consists of three stages: G1, S, and G2.

The mitotic phase includes mitosis and cytokineses.

Interphase is longer and more complex than mitosis.

Interphase is responsible for DNA replication, while mitosis is responsible for cell growth.

During prophase, the nucleoli disappear, the mitotic spindle forms, and the centrosomes separate.

Metaphase involves the alignment of chromosomes at the metaphase plate, with kinetochores attached to microtubules.

Anaphase is the shortest stage of mitosis, where sister chromatids are pulled apart, becoming individual chromosomes.

Telophase is when the nuclear envelope reforms, chromosomes decondense, and cytokinesis begins.

Cytokinesis is the division of the cytoplasm, resulting in two daughter cells.

Meiosis I is the first division of meiosis, in which homologous chromosomes are separated from each other.

Meiosis II separates sister chromatids, resulting in four haploid daughter cells.

Crossing over is a process that happens during prophase I of meiosis, making sister chromatids no longer identical.

During independent assortment, each human can potentially produce over 8.3 million different gametes in meiosis I.

A couple can potentially produce over 64 trillion different zygotes during fertilization.

Crossing over is a key factor in creating genetic diversity.

Synapsis is the pairing of homologous chromosomes during prophase I of meiosis.

A chiasma is the site where crossing over occurs.

Recombinant chromosomes are chromosomes that have undergone crossing over, resulting in the exchange of genetic material.