Biology Test pt 2

• -Homogeneous mixtures of two or more pure substances
• - The solute is dispersed uniformly throughout the solvent
• ex. sugar in water
• - Solvent molecules are attracted to the solute molecules

change in the physical state of a substance

• - A solution of a substance can dissolve no more of that substance (solute) and additional amounts of it will appear
• unsaturated
• saturated
• supersaturated

Will increase the solubility of a solute in any given solvent

Net movement of solvent from the area of higer solvent concentration to the area of lower solvent concentration

• - Pressure required to stop osmosis
• Positive number: water will go from the cell to the extracellular fluid
• Negative number: water will go from the extracellular fluid to the cell

• - Suspensions of particles larger than individual ions or molecules, but to small to be settled out by gravity
• - Tyndal Effect: Colloidal suspensions can scatter rays of light

- Aids in the emulsification of fats (lipids) & oils in aqueous solutions

• - Composed of chromatin & contains the hereditary units, or genes
• - Woven up in histone (associated packing proteins) to form nucleosome
• - Wind & unwind DNA to be able to transcribe
• 

• - Ordered, visual representation of the chromosomes in a cell
• - Chromosomes arranged by pairs according to their size, shape, & general appearance in mitotic metaphase

Constricted region of a chromosome where sister chromatids are attached to one another and where the chromosome attaches to a spindle fiber

• - Genes that can occupy the same gene locus (on different chromosomes)
• - Alternative form of a gene

• - A section of a DNA molecule that contains the code for making one polypeptide
• - Unit of heredity existing as alleles on the chromsomes

• - Similarly constructed chromosomes that have the same shape & contain genes for the same trait
• Look the same
• Control the same traits
• May code for different forms of each trait
• Independent origin- each one was inherited from a different parent

- Haploid sex cell; an oocyte or a sperm that join during fertilization to form a zygote

• - Cell possessing a single copy of each chromosome
• - Half the diploid number; the number of characteristic of gametes that contain only one set of chromosomes
• Human sex cells

• - Cell processing 2 copies/sets of each chromosomes
• - Twice the number of chromosomes found in the gametes
• Human body cells

• - G1: cells undergo majority of growth
• - S: each chromosome replicates (synthesizes) to produce sister chromatids
• Attach at centromere
• Contains attachment site (kinetochore)
• - G2: chromosomes condense & synthesize proteins needed for cell division
• 

• - Functions: reproduction, growth & development, tissue renewal
• - Part of the cell cycle
• - Interphase
• G1: growth
• S: growth & DNA replication
• G2: growth & final preparations for division
• - 90% of the cell cycle

• - Type of cell division in which daughter cells receive the exact chromosomal & genetic make up of the parental cell; occurs during growth & repair
• - Produces 2 daughter cells with 46 chromosomes each
• 

• - Nucleolus has disappeared, and duplicated chromosomes are visible.
• - Chromosomes begin moving apart & spindle is in the process of forming
• 

• - Centromeres of duplicated chromosomes are aligned at the metaphase plate (center of fully formed spindle)
• - Centromeric spindle fibers are attached to the sister chromatids come from opposite spindle poles
• - One of the longest stages
• 

• - Sister chromatids part & become daughter chromosomes that move toward the spindle poles
• - One of the shortest stages
• 

• - Daughter cells are forming as nuclear envelopes & nucleoli reappear
• - Chromosomes become less condense
• 

• - Division of the cytoplasm following mitosis & meiosis
• - Animal cells: constriction belt of actin filaments
• - Plant cells: cell wall
• 

• - Includes the centrosomes, spindle micro-tubules & the asters
• - Controls chromosome movement during mitosis/meiosis
• 

- Alleles of unlinked genes segregate independently of each other during meiosis so that the gametes contain all possible combination of alleles

• - Exchange of corresponding segments of genetic material between non sister chromatids of homologous chromosomes during synapses of meiosis
• 

- Transmission of traits from one generation to the next

- Show that offspring differ somewhat in appearance from parents & siblings

• - Type of nuclear division that occurs as part of sexual reproduction in which the daughter cells receive the haploid number of chromosomes in varied combinations
• 

• - Homologous chromosomes come together & line up side by side
• - Exchange genetic material (crossing-over)
• - Form tetrads
• 

• - Homologue chromosomes align at the metaphase plate
• 

• - Pairs of homologous chromosomes separate
• - Independent assortment occurs
• 

• - Occurs at the end of Meiosis I
• - Form 2 Haploid daughter cells
• - Cytokinesis usually occurs simultaneously
• 

- Period of time between meiosis I & meiosis II during which no DNA replication takes place

• - Simliar to prophase I
• - Chromosome start moving to metaphase plate
• - The nuclear envelope breaks down, and the spindle apparatus forms.
• 

• - Chromosomes align at the metaphase plate
• 

• - The centromeres separate, and the two chromatids of each chromosome move to opposite poles on the spindle.
• - The separated chromatids are now called chromosomes in their own right.
• 

• - A nuclear envelope forms around each set of chromosomes
• - Cytokinesis takes place, producing four daughter cells (gametes, in animals), each with a haploid set of chromosomes
• - Because of crossing-over, some chromosomes are seen to have recombined segments of the original parental chromosomes.
• 

• - Production of oocytes in females by the process of meiosis & maturation
• - Oocyte: Female gamete, or egg prior to fertilization
• 

• - Production of sperm in males by the process of meiosis & maturation
• - Spermatid: the functional product of meiosis II; becomes sperm
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