Cell Cycle and Mitosis

<p>Lack of genetic diversity (D)</p> Signup and view all the answers

<p>By ensuring daughter cells have the same chromosome number and type as the parent cell (D)</p> Signup and view all the answers

<p>Meiosis (C)</p> Signup and view all the answers

<p>Mitosis (A)</p> Signup and view all the answers

<p>To organize and condense DNA into nucleosomes. (B)</p> Signup and view all the answers

<p>They coil tightly and condense, making them more dense. (A)</p> Signup and view all the answers

<p>Sister chromatids (A)</p> Signup and view all the answers

<p>1 (D)</p> Signup and view all the answers

<p>Karyotype (B)</p> Signup and view all the answers

<p>20 nucleotides (C)</p> Signup and view all the answers

<p>Interphase (D)</p> Signup and view all the answers

<p>The length of a football field (A)</p> Signup and view all the answers

<p>To protect the DNA from unraveling (C)</p> Signup and view all the answers

<p>Anaphase (B)</p> Signup and view all the answers

<p>To pull the chromosomes towards opposite poles (B)</p> Signup and view all the answers

<p>Reformation of the nuclear envelope around each set of chromosomes (B)</p> Signup and view all the answers

<p>Animal cells form a contractile ring; plant cells form a cell plate. (C)</p> Signup and view all the answers

<p>Two genetically identical daughter cells (A)</p> Signup and view all the answers

<p>20 chromosomes (A)</p> Signup and view all the answers

<p>Active transport coupled with energy from ATP hydrolysis (D)</p> Signup and view all the answers

<p>Uncontrolled cell division (B)</p> Signup and view all the answers

<p>Telophase (A)</p> Signup and view all the answers

<p>Cytokinesis (A)</p> Signup and view all the answers

<p>To control the timing of the cell cycle (D)</p> Signup and view all the answers

<p>Cyclins (D)</p> Signup and view all the answers

<p>To pause the cycle if critical processes are incomplete (A)</p> Signup and view all the answers

<p>Do not divide once formed (A)</p> Signup and view all the answers

<p>The duplication of chromosomes prior to division (B)</p> Signup and view all the answers

<p>To organize and separate chromosomes ensuring each daughter cell receives a complete set. (A)</p> Signup and view all the answers

<p>S phase (D)</p> Signup and view all the answers

<p>The alignment of chromosomes at the cell's equator. (B)</p> Signup and view all the answers

<p>They condense into visible structures, forming chromatids joined at the centromere. (C)</p> Signup and view all the answers

<p>The cell prepares for division by creating additional organelles and materials. (C)</p> Signup and view all the answers

<p>To initiate the formation of the spindle apparatus, which separates the chromosomes. (B)</p> Signup and view all the answers

<p>It breaks down and disappears. (D)</p> Signup and view all the answers

<p>The cell replicates its DNA, creating sister chromatids. (D)</p> Signup and view all the answers

<p>The cell grows in size and collects materials needed for the next steps. (D)</p> Signup and view all the answers

<p>Two copies of a chromosome joined at the centromere, known as sister chromatids. (D)</p> Signup and view all the answers

The process where a single cell divides into two identical daughter cells.

The growth of multicellular organisms happens by increasing the number of cells through mitosis.

Mitosis replaces damaged or worn-out cells, maintaining tissue health.

Some organisms reproduce asexually through mitosis, producing offspring identical to the parent.

Sexual reproduction involves meiosis, which produces gametes (sex cells like egg and sperm).

The process of creating gametes (sex cells) through cell division.

The fusion of two gametes (egg and sperm) to form a zygote (the first cell of a new organism).

Chromosomes are thread-like structures found in the nucleus of every cell. They carry genetic information, like a set of instructions for building and maintaining an organism.

DNA, or deoxyribonucleic acid, is a molecule that carries genetic instructions. It's essentially a code that dictates an organism's characteristics.

Histones are proteins that help organize and condense DNA into compact bundles called nucleosomes.

A nucleosome is a basic unit of DNA packaging. It consists of a length of DNA wrapped around a core of eight histone proteins.

A karyotype is a photographic representation of all the chromosomes in a cell, arranged in pairs according to size and shape.

Chromosomes are not always visible under a microscope. When a cell is not dividing, they are thin and uncoiled. However, when a cell is preparing to divide, chromosomes condense and become more visible.

Humans have 46 chromosomes arranged in 23 pairs. One chromosome in each pair comes from the mother and the other from the father.

Sister chromatids are identical copies of a chromosome that are joined together during cell division.

During mitosis, the sister chromatids separate and move to opposite ends of the cell, ensuring each daughter cell receives a complete set of chromosomes.

Proteins that control the timing of the cell cycle.

Enzymes that work with cyclins to activate the next phase of the cell cycle.

The cell pauses the cycle if something goes wrong, like damaged DNA or incomplete replication.

A method of reproduction that produces genetically identical offspring.

Cells that do not divide once they're formed, like nerve and heart muscle cells.

The centromere divides, separating sister chromatids into individual chromosomes. Spindle fibers pull these chromosomes apart towards opposite ends of the cell.

Chromosomes reach the poles of the cell and uncoil, becoming less visible. A nuclear envelope forms around each set of chromosomes.

A ring of contractile fibers forms around the cell's center and tightens, pinching the cell in two.

A cell plate forms at the center of the cell and develops into a new cell wall, dividing the two daughter cells.

The cell cycle is tightly regulated to ensure that cells divide only when they are ready.

If errors or damage are detected during the cell cycle, checkpoints can halt the process, giving the cell time to repair the problem.

Cell cycle regulation prevents uncontrolled cell division, which is a hallmark of cancer.

The cell cycle checkpoints are triggered by signals inside and outside of the cell, coordinating the process of division.

The cell grows in size and gathers materials needed for the next phase.

The cell creates an exact copy of its DNA to ensure that each new cell gets a complete set of genetic instructions.

The cell prepares for division by producing more organelles and other essential components.

The cell divides its nucleus, ensuring each new cell gets an identical copy of the chromosomes.

The chromosomes condense, become visible, and start attaching to spindle fibers. The nucleolus disappears, and centrioles (in animal cells) migrate to opposite poles.

The chromosomes line up in the center of the cell at the metaphase plate. Spindle fibers attach to the centromere of each chromosome.

The sister chromatids of each chromosome separate and move to opposite poles of the cell. The spindle fibers shorten, pulling the chromosomes apart.

The chromosomes reach the opposite poles of the cell and start to uncoil. The nuclear envelope reforms around each set of chromosomes, forming two new nuclei.

The cytoplasm divides, creating two separate daughter cells. Each daughter cell receives one of the newly-formed nuclei and its own share of organelles.

The process of cell division allows for growth, repair of tissues, and reproduction in many organisms.