Cell Types, Cycle, and Mitosis: Key Concepts for Biology

What are the two main types of cells based on chromosome number?

Diploid (2n) and haploid (n or 1n) cells.

What is the difference between diploid and haploid cells?

Diploid cells have two copies of each chromosome, while haploid cells have one copy.

What are somatic cells?

Somatic cells are diploid cells that make up all body tissues except gametes.

What are gametes?

Gametes are haploid cells used in sexual reproduction, such as eggs and sperm.

What is a karyotype?

A karyotype is a picture of a cell's genome, showing the number and appearance of chromosomes.

What are homologous chromosomes?

Homologous chromosomes are pairs of chromosomes that contain the same genes at the same positions but may have different alleles.

What are alleles?

Alleles are different versions of the same gene that can lead to variations in traits.

What is the significance of checkpoints in the cell cycle?

Checkpoints regulate the cell cycle to ensure proper division and prevent errors.

What occurs during interphase?

During interphase, the cell grows, builds proteins, duplicates its organelles, and copies its DNA.

What happens during the mitotic phase?

The mitotic phase involves the division of genetic material (mitosis) followed by the division of the cytoplasm and organelles (cytokinesis).

What is the role of β cells in relation to Type 2 diabetes?

β cells must undergo sufficient division to secrete insulin; insufficient division leads to decreased insulin and glucose uptake.

What is the difference between sister chromatids and non-sister chromatids?

Sister chromatids are identical copies of a chromosome, while non-sister chromatids are from homologous chromosomes.

What is the role of ribosomes in cells?

Ribosomes use mRNA copies of DNA to build proteins necessary for life.

How do single-celled organisms use cell division?

Single-celled organisms use cell division for reproduction.

What is the importance of regulating the cell cycle?

Regulating the cell cycle is crucial to prevent uncontrolled cell division, which can lead to cancer.

What is the M checkpoint?

The M checkpoint is a control point in the cell cycle that ensures all chromosomes are properly aligned before division.

What is chromatin?

Chromatin is the complex of DNA and proteins that forms chromosomes within the nucleus.

What is the lifecycle of a cell?

The lifecycle of a cell includes interphase and the mitotic phase.

What occurs during cytokinesis?

Cytokinesis is the process where the cytoplasm and organelles of a parent cell are divided into two daughter cells.

How do cancer cells differ from normal cells in terms of growth?

Cancer cells grow uncontrollably and do not respond to the regulatory mechanisms that control normal cell division.

What is the function of DNA during the cell cycle?

DNA is duplicated during interphase to ensure each daughter cell receives a complete set of genetic information.

What is the role of external factors in cell division?

External factors, such as cell density and anchorage dependence, can influence when and how cells divide.

What is the relationship between homologous chromosomes and genetic variation?

Homologous chromosomes can have different alleles, contributing to genetic variation in offspring.

What is the significance of the 90% time spent in interphase?

Cells spend about 90% of their life in interphase to prepare for division and perform normal functions.

What is the first phase of mitosis?

Prophase

What happens to chromatin during prophase?

It condenses into compact sister chromatids.

What structure begins to form during prophase?

The mitotic spindle.

What occurs during prometaphase?

The nuclear envelope completely breaks down and duplicated chromosomes become visible.

What is the metaphase plate?

The central line where chromosomes line up during metaphase.

What happens to sister chromatids during anaphase?

They are separated and pulled to opposite poles of the cell.

What marks the end of mitosis?

Telophase, where new nuclear envelopes form around separated chromosomes.

What is cytokinesis?

The process of dividing the cytoplasm of the cell, resulting in two identical cells.

How do cytokinesis differ in animal and plant cells?

In animal cells, a cleavage furrow forms; in plant cells, a cell plate forms.

What are the two main parts of the cell cycle?

Mitosis and Cytokinesis.

What is the function of checkpoints in the cell cycle?

To ensure that the cell cycle proceeds correctly and that conditions are suitable for division.

What is nondisjunction?

The failure of sister chromatids to separate, leading to daughter cells with incorrect chromosome numbers.

What is cancer in relation to cell division?

A group of cells exhibiting uncontrolled growth, dividing without external signals or regulatory functions.

What is anchorage dependence?

The requirement that cells must be attached to a growth surface to divide.

What is density dependence?

The phenomenon where cells will not divide if they are crowded together.

What can lead to Type 2 Diabetes in relation to cell division?

Overstimulation of β cells due to a high fat and high sugar diet, leading to insufficient insulin secretion.

What happens to chromosomes during telophase?

They begin to de-condense back into chromatin.

What is the role of cohesin proteins during mitosis?

They glue sister chromatids together at the centromere.

What is the role of kinetochore proteins?

They attach to the ends of the mitotic spindle and help in the movement of chromosomes.

What is the significance of the mitotic spindle?

It is responsible for separating sister chromatids during mitosis.

What occurs during the G1 phase of the cell cycle?

The cell grows, builds proteins, duplicates organelles, and copies DNA.

What occurs during the G2 phase of the cell cycle?

The cell prepares for mitosis by checking for DNA damage and ensuring all DNA is replicated.

What happens to the mitotic spindle after telophase?

It dissolves, and its components are reused to form the cytoskeleton in daughter cells.

What is the role of the nucleolus during prophase?

It disappears as the cell prepares for division.

What is the result of a mutation in a cell-cycle regulating protein?

It can lead to uncontrolled cell division and cancer.

What is the importance of reviewing class notes and resources before the next class?

It helps reinforce understanding and prepares for upcoming assessments.