nurse cheung: mitosis vs meiosis and gentetics teas

mitosis

cell division that results in 2 daughter cells each having the same number and kind of chromosomes

starting cell in mitosis (diploid cell) 2n

meiosis

cell division that results in 4 daughter cells each half the number of chromosomes of the parent cell

starting cell meiosis (diploid cell) 2n

primary spermatocyte (males)

primary oocyte (females)

(mitosis and meiosis) both have 2 sets of chromosomes

46 total chromosomes

23 from mom

23 from dad

mitosis

PMAT

mitosis: prophase

pro=before

chromosomes become visible as they condense and thicken

meiosis: prophase 1

chromosome condensation and pairing of homologous chromosomes

mitosis: metaphase

m = middle

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

meiosis: metaphase 1

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

mitosis: anaphase

a = away

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

meiosis: anaphase 1

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

mitosis: telophase

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

meiosis: telophase 1

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

mitosis: cytokinesis

splits the cytoplasm of the cell

2 identical, diploid cells

meiosis: cytokinesis

splits the cytoplasm of the cell

meiosis: prophase 2

chromosome condensation in both cells

meiosis: metaphase 2

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

meiosis: anaphase 2

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

meiosis: telophase 2

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

meiosis: cytokinesis

splits the cytoplasm of the cell

4 non-identical cells (gametes)

23 chromosomes

haploid cells

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 (deoxyribonucleic acid)

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

composed of phosphate, deoxyribose (a sugar), and nitrogenous base (code for traits)

nucleotide bases

held together with hydrogen bonds

DNA nucleotide bases

adenine, thymine, cytosine, guanine

adenine

thymine

cytosine

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

plus more

regulatory genes/gene regulation

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 chromosomes from mom

-23 chromosomes from dad

which of the following best describes the function of regulatory genes in gene expression?

they produce proteins or RNAs that control the expression of other genes

RNA (ribonucleic acid)

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

present inside and outside the nucleus

-different sugar base (ribose, a sugar)

RNA nucleotide base

adenine, uracil, cytosine, guanine

(messenger) mRNA

carries genetic information to make proteins

(ribosomal) rRNA

serve as a location for protein sytheisis

(transfer) tRNA

an adaptor molecule that decodes a mRNA into a protein

polypeptide chain

transcription

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

C comes before L

transcription comes before translation

translation

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

codon

sequence of 3 consecutive nucleotides in a DNA or RNA molecule that codes for a specific amino acid

which component is essential for initiating the transcription of a gene into mRNA in eukaryotic cells

RNA polymerase

what is the role of mRNA in protein synthesis?

it serves as a template for assembling amino acids into proteins