Biology Final Exam Review Flashcards

Flashcards to review key concepts for the Biology final exam.

Meiosis

Cell division process with two main stages: Meiosis I and Meiosis II.

Crossing Over

Exchange of genetic material between homologous chromosomes; occurs during prophase I of meiosis.

Products of Meiosis

Four haploid daughter cells, each with half the number of chromosomes as the original cell.

Prophase I (Meiosis) vs. Prophase (Mitosis)

In meiosis, homologous chromosomes pair up and undergo crossing over; in mitosis, chromosomes condense without homologous pairing.

Chromosomes in Meiosis

A cell with 12 chromosomes will produce cells with 6 chromosomes each after meiosis.

Fertilization

The combination of chromosomes from two parents.

Zygote

Formed when sperm and egg unite.

Nondisjunction

Failure of homologous chromosomes or sister chromatids to separate properly during anaphase I or II of meiosis.

Somatic Cells

Body cells that are not gametes.

n

Haploid number of chromosomes.

Asexual Reproduction

Reproduction without the fusion of gametes.

Sexual Reproduction

Reproduction that involves the fusion of gametes.

2n

Diploid number of chromosomes.

Chromosome Parts

Consists of two sister chromatids, a centromere, and telomeres at each end.

Chargaff's Rule

In DNA, the amount of adenine equals thymine (A=T) and the amount of cytosine equals guanine (C=G).

Nucleotide

Consists of a phosphate group, a sugar (deoxyribose in DNA, ribose in RNA), and a nitrogenous base.

DNA vs. RNA Structure

DNA is double-stranded with deoxyribose sugar, while RNA is single-stranded with ribose sugar.

Sugar in RNA

Ribose.

Complementary DNA Strand

Determined by base pairing (A with T and C with G).

Base Pairing in DNA and RNA

In DNA, A pairs with T and C pairs with G; in RNA, A pairs with U and C pairs with G.

DNA Replication

The process of making new copies of DNA.

Helicase

Enzyme that unwinds DNA.

DNA Replication Process

Semiconservative, as each new DNA molecule retains one original strand.

mRNA Creation Location

mRNA is created in the nucleus during transcription.

Start Codon

AUG.

Cladogram

Visually represents evolutionary relationships based on shared traits.

Phylogenetic Tree vs. Cladogram

A phylogenetic tree depicts evolutionary relationships with time dimensions, while a cladogram shows relationships based on shared characteristics without time.

Age of Earth

Approximately 4.5 billion years old.

Early Earth's Atmosphere

Rich in gases like methane, ammonia, and water vapor but lacked oxygen.

Miller-Urey Experiment

Simulated early Earth conditions to demonstrate that organic compounds could be synthesized from inorganic precursors.

Binomial Nomenclature

The two-part naming system for organisms, consisting of the genus and species names.

Lamarck's Theory

Proposed that organisms could pass on traits acquired during their lifetime to their offspring.

Darwin's Theory

Natural selection, which explains how species evolve through the survival of individuals with favorable traits.

Evolution

The change in the heritable characteristics of biological populations over successive generations.

Natural Selection

The driving force of Darwin’s theory.

Artificial Selection

When humans decide what traits are most desirable in organisms.

Homologous Structures

Structures that are similar because of common ancestry.

Classification Order

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

Genus and Species Names

Genus names are capitalized and species names are lowercase, both italicized (e.g., Homo sapiens).

Homozygous Dominant Genotype

AA

Homozygous Recessive Genotype

aa

Heterozygous/Hybrid Genotypes

Aa

Incomplete Dominance

Phenotype is a blend of the two parent traits.

Codominance

Both alleles are expressed equally in the phenotype.

Sex-Linked Traits

Traits that are linked to genes on the sex chromosomes (typically the X chromosome).

Pedigrees

Charts that show the inheritance of traits within a family over generations.

Secondary Consumers

Organisms that consume primary consumers; usually carnivores or omnivores.

Ecological Relationships

Include mutualism, commensalism, parasitism, competition, and predation.

Burning Fossil Fuels

Causes an increase in carbon dioxide levels, contributing to climate change and air pollution.