biology module 1 & 2 M

What are the 7 characteristics of life?

Made of cells, grows, reproduces, responds to stimuli, uses energy, maintains homeostasis, adapts.

What’s the last part of the modern cell theory?

All cells come from pre-existing cells.

Abiotic vs. Biotic?

Abiotic = non-living (rock), Biotic = living (tree).

Levels of biological organization (smallest to largest)?

Cell → Tissue → Organ → Organ system → Organism → Population → Community → Ecosystem → Biosphere

Carbohydrates: monomer, function, elements?

Monosaccharide, quick energy, C, H, O

Lipids: monomer, function, elements?

Fatty acid + glycerol, long-term energy, C, H, O

Proteins: monomer, function, elements?

Amino acid, structure/enzymes, C, H, O, N

Nucleic acids: monomer, function, elements?

Nucleotide, store genetic info, C, H, O, N, P

What are enzymes made of?

Proteins

Do enzymes speed up reactions?

Yes, they lower activation energy.

What happens if enzymes are in the wrong conditions?

They denature (change shape).

Which cells have a nucleus?

Eukaryotic cells.

Shared organelles in all cells?

Cell membrane, cytoplasm, ribosomes, DNA

Eukaryote-only organelles?

Nucleus, mitochondria, ER, Golgi apparatus

Why is the cell membrane important?

Maintains homeostasis.

Passive vs. active transport?

Passive = no energy, Active = uses energy.

Osmosis: how does water move?

High to low concentration through aquaporins.

What happens in hypertonic solution?

Cell shrinks

Hypotonic solution?

Cell swells

Isotonic solution?

Cell stays the same

Photosynthesis vs. Cell Respiration vs. Fermentation?

Photosynthesis = makes glucose; CR = makes ATP; Fermentation = no oxygen

What type of molecule is DNA?

Nucleic acid

DNA bases?

A-T, C-G

How many chromosomes do humans have?

46 (23 from each parent)

Why copy DNA?

To prepare for cell division

DNA replication enzymes: Helicase?

Unzips DNA

DNA Polymerase?

Adds new bases

Ligase?

Seals fragments

What are the cell cycle stages?

G1 → S → G2 → Mitosis → Cytokinesis

What if checkpoints fail?

Cell self-destructs (apoptosis)

What are cancer cells?

Cells dividing uncontrollably

What does mitosis make?

2 identical body cells

Mitosis stages?

Prophase, Metaphase, Anaphase, Telophase

What is cytokinesis?

Division of the cytoplasm

What does meiosis make?

4 unique gametes (egg/sperm)

Haploid vs. Diploid?

Haploid = 1 set, Diploid = 2 sets

What causes genetic variation in meiosis?

Crossing over in Prophase I

What do genes code for?

Proteins

What are alleles?

Versions of a gene

Genotype TT means?

Homozygous dominant, Taster

Monohybrid cross results?

75% dominant, 25% recessive

Incomplete vs. Codominance?

Incomplete = blend, Codominance = both show

What does a pedigree track?

Traits through generations

Transcription location & product?

Nucleus, makes mRNA

Translation location & product?

Ribosome, makes protein

How are codons read?

In sets of 3

Mutation types?

Gene: substitution, insertion, deletion. Chromosomal: deletion, duplication, inversion, translocation

What causes variation in natural selection?

Mutation, recombination, random fertilization

What is fitness in evolution?

Ability to survive and reproduce

What does natural selection act on?

Phenotypes

Natural selection vs. genetic drift?

NS = not random; GD = random

Bacteria: autotroph vs. heterotroph?

Autotroph = makes food, Heterotroph = consumes food

Bacteria shapes?

Coccus = round, Bacillus = rod, Spirillum = spiral

Good uses of bacteria?

Digest food, decompose waste, make food, fix nitrogen

How to treat harmful bacteria?

Antibiotics

Are viruses made of cells?

No

Do viruses need a host to reproduce?

Yes

Do antibiotics work on viruses?

No

Archaea characteristics?

Extreme environments, no nucleus, unicellular

Protists vs. Fungi?

Protists = mostly unicellular, Fungi = multicellular decomposers

Three domains of life?

Bacteria, Archaea, Eukarya

Levels of classification?

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

How do non-vascular plants get water?

Absorb directly, no tubes

Xylem vs. Phloem?

Xylem = water up, Phloem = food down

What do stomata do?

Allow gas exchange

What do guard cells do?

Open/close stomata