Biology Cell Packet 2 Quiz Flashcards-Kowalski

Somatic Cells

Cells found in the body (body cells).

Cell Division and Somatic Cells

Cell division increases the number of somatic cells.

Mitosis

The division of the nucleus of the cell that splits genetic material between two new daughter cells.

Cytokinesis

Division of the cytoplasm that occurs after the cell splits into two, starting during telophase.

Apoptosis

A programmed cell death that decreases the total number of cells.

Apoptosis Occurrence

Apoptosis occurs throughout your entire life.

Why does Apoptosis occur?

Occurs when the cell detects that it is abnormal to prevent spreading of abnormal cells through mitotic division.

Importance of Cell Division

Cell division is important for growth, development, and repair of old/worn-out cells.

Mitotic Cell Division

The division of somatic cells to increase the total number of somatic cells utilizing Mitosis and Cytokinesis.

Gametes

Sex cells (sperm and egg).

Cell Cycle

All events that occur between the time a cell divides and when its daughter cells divide.

Longest Phase in the Cell Cycle

Interphase.

What happens during Interphase?

The cell functions normally and prepares for division.

Stages of Interphase

G1 (Gap 1) Stage, S (Synthesis) Stage, G2 (Gap 2) Stage.

G1 Stage of Interphase

Organelle number doubles and materials for division are collected.

S Stage of Interphase

DNA replication occurs.

G2 Stage of Interphase

Synthesis of proteins needed for division occurs.

G0 Phase

A stage of interphase after G1 where the cell does not divide, which can be temporary or permanent.

DNA form during Interphase

Chromatin form.

DNA form during Mitosis

Chromosome form.

When does the Mitotic Stage occur?

After Interphase.

Processes during Mitotic Stage

Mitosis and Cytokinesis.

Mitotic Cell Division Stage

Mitotic Stage.

Protein necessary for Cell Cycle Progression

Cyclin.

Checkpoints in Cell Cycle

G1 (Gap 1) Checkpoint, G2 (Gap 2) Checkpoint, M (Mitotic) Checkpoint.

G1 Checkpoint Function

Protein p53 stops the cell cycle if DNA is damaged.

G2 Checkpoint Function

Stops the cell cycle if DNA is not done replicating or is damaged.

M Checkpoint Function

Stops the cell cycle if all chromosomes are not aligned.

Protein in G1 Checkpoint

Protein p53.

What happens if DNA is damaged in G1 Checkpoint?

Apoptosis occurs.

Events in Apoptosis

A progressive series of events resulting in cell destruction.

Caspases

Two sets of enzymes that mediate apoptosis.

Functions of Caspases in Apoptosis

One set initiates apoptosis; the other activates enzymes that digest the cell.

Events that occur in Apoptosis

Cell rounds up, loses contact with surrounding cells, nucleus breaks up, chromatin condenses, DNA fragments, blisters form in the plasma membrane, cell undergoes fragmentation.

DNA Fragments in Apoptosis

Called blebs.

Cell Fragments in Apoptosis

Called cell fragments.

Chromatin Definition

Tangled mass of threadlike DNA in a nondividing cell; stable, messy, not good for cell division.

Chromosomes Definition

Condensed rod-shaped DNA molecules during mitotic cell division; unstable, packed/organized, good for cell division.

Diploid Definition

Somatic cells that contain a full set of chromosomes in pairs; human somatic cells have 23 pairs (46 total chromosomes).

Haploid Definition

Gametes with a half set of chromosomes; human gametes have 23 chromosomes (no pairs).

Mathematical Expression for Diploids and Haploids

Diploids-2N, Haploids-N (N is the number of chromosomes).

What does mitosis make?

Duplicate somatic daughter cells.

Type of division Mitosis represents

Nuclear division.

Chromosome Number Before/During/After Mitosis

It stays the same.

Composition of Duplicated Chromosomes

2 sister chromatids held together by a centromere.

After Mitosis, what happens to Centromere and Sister Chromatids?

Centromere splits; chromatids split and become daughter chromosomes.

Cell type during Mitosis

Always a diploid.

Centrosome Definition

Two centrioles.

Centrosomes/Centrioles in a Cell

2 centrosomes (4 centrioles).

Phases of Mitosis in chronological order

Prophase, Metaphase, Anaphase, Telophase.

What happens in Prophase of Mitosis?

Nuclear membrane disappears, centrosomes migrate to poles, centromeres start to divide, and spindle fibers appear.

What happens in Metaphase of Mitosis?

Chromosomes line up at the equator and attach to spindle fibers.

What happens in Anaphase of Mitosis?

Centromeres divide, sister chromatids are pulled to opposite poles, and preparation for cytokinesis begins.

What happens in Telophase of Mitosis?

Two nuclear membranes form, spindle fibers disappear, and cytokinesis occurs.

Indicator of cytokinesis in animal cell

Formation of cleavage furrow.

How to tell if the cell is in Interphase

DNA in nucleus is in chromatin form; nucleus appears as a solid color.

Where do cells divide in plants?

In meristematic tissues.

Difference in mitosis phases between animals and plants

No difference (same phases).

Missing organelles in plant cells related to cell division

Centrioles and asters.

Asters Definition

Centrioles and their associated spindle fibers.

What forms instead of dividing in plant cells?

A flat/small disk called a cell plate.

What must occur first for cytokinesis in plant cells?

Formation of the cell plate.

How does the cell plate form?

Golgi apparatus produces vesicles containing materials to build the cell plate.

How does the cell plate become a cell wall?

By fusing with the existing cell wall as it collects materials from the Golgi apparatus.

New plasma membranes form in plant cells after Mitosis

By collecting vesicle membranes used to build membranes for each daughter cell.

Process occurring while cytokinesis happens in plant cells

Transformation of the cell plate into a cell wall.

Where does cleavage furrow form?

In animal cells between the daughter nuclei/cells.

What happens to cleavage furrow's contractile ring as the cell splits?

It contracts until separation is complete.

Cleavage Furrow Definition

Space between daughter nuclei during separation.

Contractile Ring Definition

A series of proteins that pinch the center of the two daughter cells until separation is complete.

Effect of contractile ring contraction on cleavage furrow

The cleavage furrow increases in size.

Normal cell division timeframe

5-6 hours.

Bacterial cell division timeframe

20 minutes.

Cell division in prokaryotic cells

Binary fission.

Number of chromosomes prokaryotic cells have

One.

Prokaryotic cell shape before division

Lengthens/elongates to twice its length.

Prokaryotic cell splitting process

The cell membrane grows inward until division completes.

Meiosis Definition

Cell division resulting in 4 daughter cells (gametes).

Daughter cells produced by Meiosis

4 daughter cells.

Divisions occurring in Meiosis

2 divisions.

Meiosis results in diploid or haploid cells?

Haploid cells.

Cell type at the beginning of Meiosis

Diploid.

Homologues Definition

Pairs of chromosomes.

Alignment of homologues at the equator

Synapsis.

What happens when homologous pairs separate?

Each daughter cell receives half the pair.

Cell type after Meiosis 1

Haploid.

Genetic similarity between homologous chromosomes

Not genetically the same.

Cell types that can undergo meiosis

Primary spermatocyte or primary oocyte.

Genetic similarity of daughter cells after Meiosis 1 and 2

All daughter cells are different/unique.

Similarity of Meiosis 2 to other processes

Very similar to Mitosis.

What happens in Meiosis 1?

Synapsis occurs, pairs separate, and each daughter cell receives 1/2 the homologue pair.

What happens in Meiosis 2?

Mitosis occurs with centromeres dividing and sister chromatids migrating to opposite poles.

Ways genetic recombination occurs

Crossing Over and Independent Alignment.

Purpose of Genetic Recombination

Promotes genetic variability, strengthening the species.

Crossing-Over Definition

Exchange of segments of DNA between homologues.

Independent Alignment Definition

Random assortment of homologues.

How to calculate combinations for daughter cell DNA without crossing over

2^(number of chromosomes).

Are all eggs and sperm genetically the same?

No, they are all genetically different.

Pollen Definition

Plant sperm.

When does crossing over occur?

During synapsis.