Untitled Flashcards Set

Nucleus

Contains most of the cell’s DNA, organized into chromosomes.

Chromatin

Condenses into visible chromosomes when a cell divides.

Mitosis

Process of cell division discovered by Walther Flemming.

Components of Chromatin

DNA (nucleotides) and Histones (proteins that help DNA coil).

Nitrogenous Bases in DNA

Adenine (A), Guanine (G), Cytosine (C), Thymine (T).

Structure of Chromosome

Two sister chromatids joined at a centromere.

Genes

Segments of DNA coding for proteins, units of heredity.

Reasons for Cell Division

Growth, replacement, repair, reproduction.

Phases of Cell Cycle

Interphase and M-Phase.

Stages of Interphase

G1 (First Growth), S (Synthesis), G2 (Second Growth).

Types of Cell Division

Mitosis (diploid cells) and Meiosis (haploid gametes).

Importance of Mitosis

One parent cell divides into two identical daughter cells, maintaining chromosome number.

Phases of Mitosis

Prophase, Metaphase, Anaphase, Telophase.

Cytokinesis

Division of cytoplasm, cleavage furrow forms in animal cells.

Functions of Mitosis

Growth, repair, replacement, asexual reproduction, maintains chromosome number.

Meiosis

Cell division that produces gametes, reducing chromosome number by half.

Importance of Meiosis

Ensures correct chromosome number after fertilization and creates genetic variation.

Crossing Over

Exchange of genetic material between non-sister chromatids, leading to genetic recombination.

Differences between Mitosis and Meiosis

Mitosis produces 2 diploid cells, while meiosis produces 4 haploid cells that are genetically varied.

Nuclear Divisions in Meiosis

Meiosis I reduces chromosome number; Meiosis II is similar to mitosis.