Biology CP Midterm Review

LARGE  SMALL Biosphere Ecosystem Organism Cell DNA /Genes Scale of Biology

Domain is BROADEST category- 3 domains ARCHAEA BACTERIA EUKARYA- more complex- eukayotic- –4 kingdoms Protists Fungi Plants Animals –Invertebrates –Vertebrates Mammals DOMAINS of LIFE Small, single celled, prokaryotic

Characteristics of Eukaryotic Cells Membrane-bound nucleus (contains DNA) Organelles in cytoplasm Larger, can be multicellular cell membrane organelles nucleus

Eukaryotic Cells- Plants & Animals ANIMAL cells - No cell wall - many small vacuoles PLANT cells - Chloroplasts - Cell wall - 1 large vacuole

Characteristics of Prokaryotic Cells No nucleus or organelles DNA in cytoplasm Small, all are unicellular cell membrane organelles nucleus

Structure of Cell Membrane FLUID MOSAIC MODEL cell membrane protein cholesterol protein carbohydrate chain protein channel

Osmosis- SALT SUCKS Movement of WATER across selectively permeable membrane

Four groups of large Biomolecules Carbohydrates –Sugar (mono/disaccharide), starch/fiber (polysacch) –Main source of body’s energy Lipids/fats/sterols –Make up membranes, used for energy Proteins –Structural building blocks, enzymes Nucleic Acids –DNA/RNA, stores genetic ‘code’

Enzymes = proteins that speed up specific reactions in cells Activation energy: “start up” energy to get a chemical reaction started Catalyst: anything that speeds up chemical reactions Enzyme: special protein – catalyst in organisms –Ex: sucrase, amylase –Anything with suffix -ase = enzyme Substrate: binds to the enzyme; must fit into active site –Ex: sucrose Active site: place (on enzyme) where the substrate fits –Lock and key

Cell Cycle I. Interphase (90% time) 1.) G1 phase- cell grows 2.) S phase- genetic material duplicates 3.) G2 phase- cell prepares to divide DNA loosely packed as chromatin II. Mitosis (10%) 4.) M phase (mitotic)- mitosis (PMAT) and cytokinesis

Diploid (2n) vs. Haploid (n) Cells Body Cells Contain both homologous chromosomes Total = 46 chromosomes (44 autosomes & 2 sex) Reproduce through mitosis Sex Cells (egg and sperm) Contain only one of the homologous chromosomes Total = 23 chromosomes (22 autosomes & 1 sex) Made through meiosis

Meiosis results in 4 haploid gamete cells –Meiosis occurs in sex cells –Involves 2 cell Divisions* –Meiosis produces 4 gametes* which are haploid (n) cells. –Note: This picture Does not show Chromosome #’s. Meiosis 1 Meiosis 2 4 haploid gametes Parent Cell During interphase 2n nn nn n n

Mitosis vs. Meiosis Mitosis and meiosis are types of nuclear division that make different types of cells. Mitosis makes more diploid (2n) cells Meiosis occurs in sex cellsMitosis occurs in body cells Meiosis produces gametes (haploid (n) cells)

DNA is composed of four types of nucleotides. DNA (polymer) is made up of a long chain of nucleotides (monomer). Each nucleotide has three parts: –phosphate group –Sugar (deoxyribose) –Nitrogenous base There are 4 different types of nucleotides phosphate group deoxyribose (sugar) nitrogenous base

Quick Review… GENE= unit of heritable information in DNA (region with coding for a trait) If nucleotides are the building blocks of DNA/RNA, what are the building blocks of PROTEINS?? RNA vs. DNA… GENE ANIMATION –RNA has a ribose sugar. –RNA has uracil instead of thymine. –RNA is a single-stranded structure.

REPLICATION: Exact copy of DNA is made using each half as a template (in nucleus) TRANSCRIPTION: Converting DNA sequence (gene) into a single stranded mRNA molecule (in nucleus) TRANSLATION: Converting mRNA message into a polypeptide/protein (in cytoplasm, done by ribosomes) DNA Replication TRANSLATION DNA RNAPROTEINS TRANSCRIPTION

Genetics Basics 1. ALLELE = alternative forms of a gene… ex. Brown hair allele, black hair allele (gene is for hair color) 2. You have TWO alleles for each character- one came from your mom, one from your dad 3. Each gamete carries ONE allele (in MEIOSIS, the parent cell splits its genetic information in half… if mom was Bb, each egg will get either B or b) 4. GENOTYPE = Ee (heterozygous) … determined by genetic code/genes/DNA PHENOTYPE= Red eared… physical expression, based on PROTEINS

Dihybrid Cross- HOW TO Step 1- Determine Genotype of parents CCPP X ccPp Step 2- Determine different combinations of parent alleles (USE FOIL) CCPP … F=CP or O=CP or I=CP or L=CP ccPp … F=cP or O=cp or I=cP or L=cp Step 3- Line pairs up along 4x4 P-square Each offspring will have 4 letters, describe with two words for phenotype!

Intermediate/Incomplete and Codominance Keys to remember: –Mixed offspring will be HETEROZYGOUS –Both letters are capitalized –Denote with superscripted letters (C W or L T etc) INTERMEDIATE/INCOMPLETE- Blend of parent traits C R C R (red) x C W C W (White) = C R C W (Pink) CODOMINANCE- Both traits show C B C B (black) x C W C W (White) = C B C W (stripes)

Many genes may interact to produce one trait. Polygenic traits = produced by two or more genes Ex.- Eye, skin color Wide range of variation Order of dominance: brown > green > blue.

Sex-Linked Traits Gene located on sex chromosome, usually the X … Eye color in fruit flies (Red = R, white=r) Females (XX) carry two copies of the gene, may carry the trait, but not show it (X R X r ), will have white eyes ONLY if she has copies (X r X r ) Males (XY) carry one copy (no other X to ‘hide’ it), so they will either HAVE IT (X r Y ) or NOT HAVE IT (X R Y) *Males only have to inherit ONE copy, whereas females must inherit 2!*

Disorders as SEX-LINKED Traits Usually located on X chromosome More common in males… Colorblindness NOTICE: -No male carriers -More common in Males than females

Principle of segregation during gamete formation, a particular allele for one character can be paired with either allele of another character (useful for dihybrid crosses, FOIL) Principle of independent assortment genes are located on chromosomes, behavior (separation) of chromosomes during meiosis and fertilization accounts for inheritance patterns Chromosome theory of inheritance the two alleles for a character segregate (or separate) during meiosis, so each gamete carries only one allele for each character

Disorders as DOMINANT Traits Fewer of these than Recessively inherited disorders, typically HETEROZYGOUS Not so bad: polydactyly Not Hot: Achondroplasia, Huntington’s disease LETHAL DOMINANT alleles- embryos that are homozygous are typically miscarried (do not survive) *those with disorder are typically Heterozygous