Bio Midterm Studying

Evolve but remember

Significance of Meiosis

Provides chromosomal variation in an organism’s gametes

If chromosomes have been duplicated but not lined up and the membrane begins to break down, what phase of mitosis is this?

Prophase

Basic Purpose of Science

To understand things around us

Biosphere

Part of earth where all life exists

Ecosystem

All living and nonliving things

Community

Populations living together

Organism parts from BIGGEST TO SMALLEST

Systems, organs, tissues, cells, molecules, atoms

Francesco Redi

Carried out a rotting meat experiment

\-He manipulated the variable of whether the container was open or covered by gauze

Redi’s Experiment

First Jar: No flies or air able to enter = no maggots

Second Jar: Competely open, flies and air get in = maggots

Third Jar: Gauze on top, air gets in = no maggots

John Needham’s hypothesis

Believed spontanteous generation could occur under right conditions

John Needham’s experiment

Sealed a bottle of gravy and hetaed it - after several days it was full of life

Lazarro Spallanzani

Didn’t believe Needham had heated his gravy enough, and carried out his own experiment

Lazarro’s Experiment

Boiled two containers of gravy, the container that was left open showed much growth in days while the sealed container remained free of life

Louis Pasteur

Designed a flask that had a curved neck, made the flask open to air but microorganisms didn’t get in

Pasteur’s experiment

Broth was sterilized, no microbes present in the broth

\-Break the neck of the flash, microorganisms get in the broth

Proton + Neutron weight

1 AMU

Electron weight

0 AMU

What is an element

A pure substance of only one type of atom

What are isotopes

Atoms of an element with different numbers of neutrons

Chemical Compound

A substance formed by combining 2 or more elements in specific proportions

Ionic bond

One or more electrons transferred between a metal and a nonmetal

Covalent bond

Sharing of electrons between nonmetals

Van der Walls

Intermolecular forces of attraction betwenen molecules

Why is a water molecule ‘polar’?

Uneven distribution of electrons between hydrogen and oxygen

Hydrogen Bonds

Formed by water molecules attracting each other

Cohesion

Allows water to bead with itself

Adhesion

Allows water to be attracted to different substances like water in a graduated cylinder

Mixture

Two or more elements or compounds physically mixed together

Solution

Has evenly mixed elements

PH Scale

Scale of 0 to 14, (7 neutral)

\-below 7 are acids

\-above 7 are bases

Polymerization

Small units, monomers, are joined together to form polymers

Carbohydrates

Made of Carbon, Hydrogen, and Oxygen

Ratio - 1:2:1

Monossacharides

Simple sugars

Disaccharides

Double sugars

Glucose

A monosaccharide and our main energy sugar - stored as glycogen

Lipids

Made from Carbon, Hydrogen, and some Oxygen

\-Not found in a ratio

\-Important for long term energy, waterproofing, and cell membrane function

Nucleic Acids

Made of repeating units called nucleotides

\-Store and transmit genetic information (DNA and RNA)

DNA

\-Contains deoxyribose sugar

\-Double stranded

RNA

\-Contains the sugar ribose

\-Single stranded

Proteins

Macromolecules containing Carbon, Hydrogen, Oxygen, Nitrogen

\-Made of amino acids

Chemical Reaction

Changes one set of chemicals into another

\-Can release energy, commonly spontaneous

Enzymes

Organic catalysts that help reactions occur in the body that may be slow or have high activation energies

Denaturation

The general breakdown and shape change of the enzyme where it cannot function properly

Anton van Leeuwenhock

Used a simple microscope to study small organisms in a drop of water

Robert Hooke

Used a light microscope to view plant tissue

-coined the term “cells” to represent the small chambers he viewed

Matthias Schleiden and Theodor Schwann

Concluded that all plants and animals are made of cells

Rudolf Virchow

Came up with “all cells come from pre existing cells”

Prokaryotes

\-Small and simple cells

\-Have cell membranes and cytoplasm

\-Don’t contain nuclei

Eukaryotes

\-More complex have numerous cellular organelles

\-Many are large and multicellular

Robert Brown

He who identified the nucleus

Cytoskeleton

Network of filaments that gives the cell shape

\-Contains Microtubules and Microfilaments that help in cell division and movement

Endoplasmic Reticulum

Involved in protein synthesis

Ribosomes

The sites of protein synthesis

Golgi Apparatus

Packaging, procession, secretion of materials such as proteins

Lysosomes

Filled with enzymes that help in digestion and the breakdown of worn out cell parts

Vacuoles

Help in storage of water, salts, proteins, and carbohydrates

Osmosis

Pssive transport of water through a selectively permeable membrane

Endocytosis

Movement of materials through pockets of the cell membrane

Photosynthesis equation

6CO2 + 6H20 + Light = C6H12O6+6O2

Chlorophyll

Green pigment found in chloroplasts that harnesses energy of sunlight

\-Light energy is converted into chemical energy to form glucose from reactants

Carotenoids

Other pigment found in autotrophs

Light reactions of photosynthesis

Reactions that take place during daylight hours and occur in the grana

\-Energy absorbed by chlorophyll

\-Water is split into hydrogen ions and oxygen

Dark reactions of photosynthesis

\-CALVIN CYCLE

\-Take place in the stroma of the chloroplast

\-Using ATP and hydrogen, glucose is formed

Factors affecting photosynthesis

Temperature and light

\-Can level out as enzymes start to denature at too high temoeratures

Aerobic respiration

Takes place in the presence of oxygen

Glycolysis

Stage of cell respiration that takes place in the cytoplasm of the cell

\-Anaerobic

\-Pyruvic acid broken down into a two compound carbon called acetic acid

2 ATP molecules used, 4 are made for a net gain of 2 ATP

Krebs Cycle

Takes place in the matrix of the inner membranes of the mitochondria

\-Produces 4 carbon dioxide and 2 ATP molecules

Electron Transport Chain

Final stage, occurs in inner membranes of mitochondria

\-Electrons moved from carrier to carrier until they combine with an oxygen and hydrogen to form water

\-Special proteins called ATP synthases converts ADP to ATP, up to 34 per original glucose

NADH molecule

Carrier molecule that transfers electrons from the original glucose molecule to the electron transport chain

Fermentation

Process that makes ATP without using oxygen

Lactic Acid Fermentation

Occurs in muscles

\-Only 2 ATP molecules formed

\-Good for short term boosts of energy

Alcoholic Fermentation

Occurs with some organisms such as yeast, produce ethyl alcohol and carbon dioxide

Why does a cell divide?

\-DNA gets overloaded

\-Exchange of Materials gets less efficient

\-Ratio of surface area to volume rapidly decreases

Chromosomes

Carry genes

\-46 in total, 22 pairs of autosomes and 1 pair of sex chromosomes

\-Made up of 2 sister chromatids that are attached by a centromere

Cell Cycle

The process where a cell grows, prepares for division, and then divides into 2 daughter cells (THIS PROCESS REPEATS)

Interphase

Part of cell cycle where the cell grows, DNA replicates, and the cell carries out its job description

Prophase

\-Phase where chromosomes become visible

\-Centrioles move to opposite ends of the cell

\-Spindle formation organizes to separate chromosomes

Metaphase

\-Chromosomes line up along the center of the cell

\-The centromere of each chromosome is connected to the spindle

Anaphase

\-The centromeres separate, sister chromatids become individual

\-Chromosomes end up near the poles of the cell in two groups

Telophase

\-Chromosomes begin to break up back into chromatin form

\-Nuclear envelope reforms

\-Nucleolus becomes visible again

Cytokinesis

\-Actual division of cytoplasm to form two separate cells

(In plants, a ‘plate’ structure is formed)

Cyclins

Regulate the timing of the cell cycle

Contact Inhibition

Cells will continue to divide until they come into contact with other cells

Cancer

A disease where tumors form and spread throughout the body, causing damage

Homologous Chromosomes

A cell containing both sets of these are said to be Diploid or 2N

\-Number is 46 in humans

Gametes

Contain a single set of chromosomes, Haploid of N

\-Number is 23 in humans

Prophase 1 Meiosis

Each chromosome will pair with it’s homologous chromosome to form a Tetrad

Crossing Over

Process where portions of the chromatids can be exchanged

Metaphase 1 Meiosis

Spindle fibers attach to chromosmes, chromosomes will be at the center of the cell, lined up

Anaphase 1 Meiosis

Spindle fibers will pull chromosomes towards opposite ends of the cell

Telophase 1 Meiosis

The nuclear membranes reform and the cell separates into two daughter cells

Meiosis 2

The two cells formed in Meiosis 1 now go through another set of divisions

(DNA NOT REPLICATED AGAIN)

\-Results in four haploid cells

Gamete formation

In males, the gametes formed are sperm cells

(4 sperm produced after Meiosis)

In females, the gametes formed and egg cells

(1 egg cell and 3 polar bodies formed)

Gregor Mendel

Austrian monk who worked with garden peas

\-Did cross pollination experiments to observe different traits

Segregation

Each gamete only carries one copy of each gene

Genotypes

Parental letters shown along the top and side of a punnett square

Homozygous organisms

Organisms with one type of allele for a trait

Heterozygous/Hybrid organisms

Organisms with two different alleles for a trait

Phenotype

What an organism physically looks like

Law of Independent Assortment

States that genes for different traits segregate independently during the formation of gametes

EX: F2 gen of a dihybrid cross has ratio of 9:3:3:1