bio terms to know

1.

Fitness

An organism’s ability to survive and reproduce in its environment.

2.

Prokaryote

A cell that lacks a nucleus and membrane-bound organelles (e.g., bacteria).

3.

Eukaryote

A cell that has a nucleus and membrane-bound organelles (plants, animals, fungi, protists).

4.

Bacteria

Single-celled prokaryotic organisms with cell walls containing peptidoglycan.

5.

Archaea

Single-celled prokaryotes genetically distinct from bacteria; often live in extreme environments.

6.

Eukarya

The domain of life that includes all eukaryotic organisms.

7.

LUCA (Last Universal Common Ancestor)

The most recent common ancestor of all living organisms on Earth.

8.

Central Dogma of Molecular Biology

The flow of genetic information: DNA → RNA → Protein.

9.

Nucleotide

The building block of DNA and RNA; made of a sugar, phosphate group, and nitrogenous base.

10.

Deoxyribonucleic Acid (DNA)

The molecule that stores genetic information in cells.

11.

Ribonucleic Acid (RNA)

A molecule that helps carry out instructions from DNA to make proteins.

12.

Protein

A molecule made of amino acids that performs structural, functional, and enzymatic roles in cells.

13.

Genetic Code

The set of rules by which DNA/RNA sequences are translated into proteins.

14.

Chromosome

A long DNA molecule wrapped around proteins that carries genes.

15.

Homologous Chromosomes

A pair of chromosomes (one from each parent) that carry the same genes at the same loci.

16.

Sister Chromatids

Identical copies of a chromosome joined together after DNA replication.

17.

Centromere

The region of a chromosome where sister chromatids are attached.

18.

Regression

A statistical method used to model the relationship between variables.

19.

Correlation

A measure of how strongly two variables are related.

20.

Standard Deviation

A measure of how spread out data values are from the mean.

21.

Standard Error

An estimate of how much the sample mean varies from the true population mean.

22.

p value

The probability that observed results occurred by chance if the null hypothesis is true.

23.

Keeling Curve

A graph showing the steady rise of atmospheric CO₂ over time.

24.

Troposphere

The lowest layer of Earth’s atmosphere where weather occurs.

25.

Stratosphere

The atmospheric layer above the troposphere; contains the ozone layer.

26.

Phenotype

The observable traits of an organism (physical or biochemical).

27.

Ploidy

The number of sets of chromosomes in a cell.

28.

Haploid (n)

A cell with one set of chromosomes (e.g., gametes).

29.

Diploid (2n)

A cell with two sets of chromosomes (most body cells).

30.

Polyploid

A cell with more than two sets of chromosomes.

31.

Genome

The complete set of an organism’s DNA.

32.

Gene

A segment of DNA that codes for a functional product (usually a protein).

33.

Gene Loci

The specific location of a gene on a chromosome.

34.

Allele

A different version of a gene.

35.

Genotype

The genetic makeup (allele combination) of an organism.

36.

Homozygous

Having two identical alleles for a gene.

37.

Heterozygous

Having two different alleles for a gene.

38.

Discrete Trait

A trait that has clearly defined categories (e.g., purple or white flowers).

39.

Complete Dominance

When one allele completely masks the effect of another.

40.

Incomplete Dominance

When heterozygotes show a blended phenotype.

41.

Codominance

When both alleles are fully expressed in the heterozygote.

42.

Genetic Pure Line

A population that is homozygous for a trait and consistently produces the same phenotype.

43.

Genetic Hybrid

An organism produced by crossing two genetically different individuals.