9th grade Bio finals

Cell Membrane

Controls what enters and leaves the cell; selectively permeable

Osmosis

The diffusion of water across a selectively permeable membrane

Diffusion/passive transport

The movement of molecules from high to low concentration

Active Transport

Movement of molecules from low to high concentration using energy (ATP)

Passive Transport

Movement of molecules without energy from high to low concentration

Equilibrium

When molecules are evenly spread out (balanced concentration)

Semi-permeable membrane

A membrane that allows some substances to pass but not others

Photosynthesis

Process in plants where light energy is converted to glucose; occurs in chloroplasts

Photosynthesis Equation

CO₂ + H₂O + sunlight → C₆H₁₂O₆ + O₂

Chloroplast

Organelle where photosynthesis occurs

Cellular Respiration

Process of converting glucose into ATP energy; occurs in mitochondria

Cellular Respiration equation

C₆H₁₂O₆ + O₂ → CO₂ + H₂O + ATP

ATP

Energy molecule used by cells

Mitochondria

Organelle where cellular respiration takes place

Mitosis

Cell division producing 2 identical diploid cells; used for growth and repair

Meiosis

Cell division producing 4 unique haploid gametes (sex cells)

Diploid

Cell with full set of chromosomes (2n)

Haploid

Cell with half the number of chromosomes (n)

Gametes

Sex cells (sperm and egg)

Crossing Over

Exchange of genes between chromosomes during meiosis; creates genetic diversity

Chromosome

Coiled DNA carrying genetic info

DNA

Deoxyribonucleic acid; carries genetic info

RNA

Ribonucleic acid; used to help make proteins

mRNA (Messenger RNA)

carries genetic code from DNA to ribosome

tRNA (Transfer RNA)

Type of RNA that brings amino acids to ribosome

rRNA (Ribosomal RNA)

Makes up the ribosome

Nucleotide

Building block of DNA; contains a sugar, phosphate, and base

DNA Bases (Adenine, Thymine, Cytosine, Guanine)

A-T, C-G

Replication

Copying DNA before cell division

Transcription

DNA → mRNA (in the nucleus)

Translation

mRNA → protein (at the ribosome)

Codon

3-base sequence on mRNA that codes for an amino acid

Protein Synthesis

The process of making proteins using DNA, RNA, and ribosomes

Gene

A segment of DNA that codes for a protein

Allele

A version of a gene

Dominant Allele

An allele that shows if present (uppercase letter)

Recessive Allele

Only shows if no dominant allele is present (lowercase)

Genotype

The genetic makeup (ex: Aa, AA)

Phenotype

The physical trait (ex: brown eyes)

Homozygous

Two of the same alleles (AA or aa)

Heterozygous

Two different alleles (Aa)

Punnett Square

Tool used to predict offspring genetics

Gregor Mendel

Father of genetics; studied pea plants

Law of Segregation

Alleles separate during gamete formation

Law of Independent Assortment

Alleles of different genes separate independently

Natural Selection

Process where organisms with favorable traits survive and reproduce

Survival of the Fittest

Organisms best suited to the environment survive

Mutation

A change in DNA that can cause variation

Adaptation

A trait that helps an organism survive

Speciation

Formation of new species

Reproductive Isolation

Barriers that prevent species from mating

Geographic Isolation

Physical separation of populations leading to speciation

Lamarck’s Theory

Traits acquired during life are passed on (wrong)

Darwin’s Theory

Traits that increase survival are passed on

Vestigial Structure

Structure that has lost its function through evolution (e.g. appendix)

Homologous Structure

Similar structure, different function (shows common ancestor)

Fossil Record

Evidence for evolution from preserved remains

Symbiosis

Close relationship between two different species

Mutualism

Both species benefit (+/+)

Commensalism

One benefits, other unaffected (+/0)

Parasitism

One benefits, other is harmed (+/-)

Producer

Makes its own food (autotroph)

Primary Consumer

Eats producers; herbivore

Secondary Consumer

Eats primary consumers; carnivore

Tertiary Consumer

Eats secondary consumers; top of food chain

Decomposer

Breaks down dead organisms; recycles nutrients

Trophic Level

Top Level in a food chain

Biomass

Total amount of living matter at a trophic level

Carrying Capacity

Maximum population an environment can support

Limiting Factor

Something that limits population growth (food, space, etc.)

Biotic Factor

Living part of the environment

Abiotic Factor

Non-living part of the environment

Biodiversity

Variety of life in an ecosystem