BZ110 exam 3

Biological levels of organization

The hierarchy of biological structures including atoms, molecules, organelles, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, and the biosphere.

Prokaryotes

bacteria & archaea; lack a nucleus, DNA is just contained in a single chromosome in their cytoplasm; can be multi or unicellular

Eukaryotes

have organelles, like the mitochondria, and have DNA; can be multi or unicellular

key differences between prokaryotes & eukaryotes

the presence of a nucleus & mitochondria (only in eukaryotes); membrane structure, ribosome structure, how transcription & translation work, presence/ absence of specific genes & other organelles

Fluid mosaic model

A model describing the structure of the plasma membrane as a dynamic and complex structure made of phospholipids and proteins.

Plasma membrane

The boundary of cells that regulates the movement of substances in and out of the cell; it is semi-permeable.

Cytoskeleton

A network of fibers that maintains cell shape, provides support, and facilitates movement within the cell.

Rough ER

The rough endoplasmic reticulum, involved in protein synthesis and processing.

Smooth ER

The smooth endoplasmic reticulum, involved in lipid synthesis, sugar synthesis, steroid synthesis, and detoxification.

Golgi apparatus

Organelle responsible for processing, tagging, and transporting cell components, often referred to as the 'post office' of the cell.

Mitochondria

responsible for ATP production through cellular respiration.

Lysosomes

Organelles that contain enzymes for breaking down waste materials and cellular debris.

DNA

2 strands; has a hydrogen, thymine has a methyl group; mil-bil of nucleotides

RNA

1 strand; uracil bonds with thymine; ribose has an oxygen on the 2’ carbon; hydroxyl group & uracil has a hydrogen; dozens to thousands of nucleotides

Genomic equivalence

The concept that every cell in an organism has the same DNA.

Transcription

The process by which DNA is copied into mRNA. original DNA template —> synthesis process —> mRNA

Translation

The process by which mRNA is used to synthesize proteins at the ribosome. mRNA —> translation —> amino acida/proteins

Mitosis

asexual cell division that results in two diploid cells. ppmat & cytokinesis

Meiosis

A two-round process of cell division that produces four haploid cells, which are gametes

Independent assortment

The random arrangement of alleles during gamete formation, contributing to genetic diversity.

Crossing over/recombination

The exchange of genetic material between homologous chromosomes during prophase I of meiosis.

Incomplete dominance

A genetic situation in which one allele does not completely dominate another allele, resulting in a combined phenotype. example: shades of color (in flowers)

Co-dominance

A genetic scenario in which both alleles contribute equally and visibly to the phenotype. example: calico cat

Epistasis

A genetic interaction where one gene can mask or modify the expression of another gene.

Discrete variation

Traits that fall into distinct categories and can be easily identified.

Continuous variation

Traits that exhibit a range of phenotypes rather than distinct categories.

Additive genetics

The concept where multiple genes contribute to a single phenotype, resulting in a continuous distribution of traits.