Mitosis vs Meiosis and Genetics - TEAS Prep

mitosis

• cell division that results in two daughter cells each having the same number and kind of chromosomes

• starting cell in mitosis (diploid cell) 2n

mitosis phases

• prophase

• metaphase

• anaphase

• telophase

• cytokinesis

prophase

• chromosomes become visible as they condense and thicken

metaphase

• chromosomes align in the cell’s center, forming a single row

anaphase

• chromatids are separated and drawn to the opposite ends of the cell by spindle fibers

telophase

• chromosomes reach the opposite sides of the cell, forming new nuclear envelopes around the chromosomes

cytokinesis

• splits the cytoplasm of the cell, two identical diploid

meiosis

• cell division that results in four daughter cells each with half the number of chromosomes of the parent cell

• starting in cell meiosis (diploid cell) 2n

  • primary spermatocyte

  • primary oocyte

meiosis phases

• prophase 1&2

• metaphase 1&2

• anaphase 1&2

• telophase1&2

• cytokinesis 1&2

prophase 1

• chromosome condensation and pairing of homologous chromosomes

metaphase 1

• chromosomes align in the middle of the cell’s center, maintaining their homologous pairs

anaphase 1

• chromosomes are separated and drawn to the opposite ends of the cell by spindle fibers

telophase 1

• chromosomes reach the opposite sides of the cell, forming new nuclear envelopes around the chromosomes

cytokinesis 1

• splits the cytoplasm of the cell

prophase 2

• chromosome condensation in both cells

metaphase 2

• chromosome align in the middle of the cell’s center, forming a single row

anaphase 2

• chromatids are separated and drawn to the opposite ends of the cell by spindle fibers

telophase 2

• chromosomes reach the opposite sides of the cell, forming new nuclear envelopes around the chromosomes

cytokinesis 2

• splits the cytoplasm of the cell

• four non-identical cells (gametes)

• haploid cells: 2 groups of 23 chromosomes

heredity

• the passing on of physical or mental characteristics genetically from one generation to another

• height, eye color, risk for certain diseases, hair color

DNA

• self-replicating material that is present in nearly all living organisms as the main constituent of chromosomes

• deoxyribonucleic acid - double helix shaped

• nucleotide

  • held together by hydrogen bonds

  • phosphate, deoxyribose (a sugar), nitrogenous bases (code for traits)

  • adenine to thymine

  • cytosine to guanine

genes

• a unit of heredity which is transferred from a parent to offspring and is held to determine some characteristics of the offspring

• protein can code for genes

structural genes

• eye/hair color, transport, structure, enzymatic activity, defense mechanisms, etc

regulatory genes

• used to control the timing, location and amount in which genes are expressed

• genes can be activated and deactivated through various mechanisms

chromosomes

• a threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes

• made up of DNA

• humans have 46 chromosomes (23 from mom and 23 from dad)

RNA

• a nucleic acid present in all living cells whose principal role is to act as a messenger carrying instructions from DNA for controlling synthesis of proteins

• ribonucleic acid, single strand

• different sugar base

• adenine to uracil

• cytosine to guanine

mRNA

• carries genetic information to make proteins

rRNA

• serve as a location for protein synthesis

tRNA

• an adaptor molecule that decodes an mRNA into a protein

transcription

• process of making an RNA copy of a gene’s DNA sequence

• RNA polymerase connects complementary RNA bases to the DNA

translation

• process of translating the sequence of a mRNA to amino acids during protein synthesis

transcription → translation

• forms single strand of mRNA → strand gets sent to ribosomes (rRNA) → translates sequence from mRNA during protein synthesis (tRNA)