bio lec 132 LT 1

Prokaryotic Cell

Lacks nucleus and membrane

Eukaryotic Cell

Contains membrane

DNA

Deoxyribonucleic acid, genetic material of organisms.

Genome

Entire library of genetic instructions inherited.

Gene Expression

Process directing cellular product manufacture.

Natural Selection

Mechanism of evolutionary adaptation through trait propagation.

Evolution

Biological change leading to species diversity.

Feedback Regulation

Process where output regulates initial stimulus.

Negative Feedback

Response reduces initial stimulus in systems.

Positive Feedback

Response amplifies initial stimulus in systems.

Charles Darwin

Proposed natural selection as evolution mechanism.

Climate Change

Long

Inductive Reasoning

Logic developed by analyzing observations.

Hypothesis

Testable explanation based on observations.

Scientific Method

Systematic approach to understanding natural phenomena.

Experiment

Controlled scientific tests to validate hypotheses.

Deductive Reasoning

Logic flows from general to specific.

Data

Recorded observations, quantitative or qualitative.

Variables

Factors measured or manipulated in experiments.

Independent Variable

Factor manipulated in an experiment.

Dependent Variable

Factor measured that is affected by independent variable.

Cell Division

Process where one cell divides into two.

Mitosis

Division of genetic material in the nucleus.

Cytokinesis

Division of cytoplasm following mitosis.

Cell Cycle

Life cycle of a cell from formation to division.

Model Organism

Species easy to grow for scientific research.

Asexual Reproduction

Reproduction without egg or cell fusion.

Sexual Reproduction

Reproduction involving fusion of gametes.

Chromosomes

DNA packaged into structures during cell division.

Proteomics

Study of sets of proteins and their properties.

Bioinformatics

Computational tools for analyzing biological data.

Interphase

Stage of cell growth and preparation for division.

Mitosis

Single cycle of chromosome separation during cell division.

Meiosis

Two cycles of chromosome separation for gamete formation.

Cell Cycle

Includes interphase and mitotic phases, 90% interphase.

Meiosis

Cell division yielding one chromosome set.

G1 phase

First gap phase of cell growth.

S phase

Synthesis phase where chromosomes duplicate.

G2 phase

Second gap phase before cell division.

Telophase

Final stage of mitosis before cytokinesis.

Cytokinesis

Division of cytoplasm after mitosis.

Mitosis

Division of genetic material in nucleus.

Binary fission

Prokaryotic cell division method.

Cleavage furrow

Animal cell structure during cytokinesis.

Cell plate

Plant cell structure during cytokinesis.

Cancer cells

Cells that escape normal division controls.

Benign tumor

Non

Malignant tumor

Invasive tumor that can metastasize.

Clone

Genetically identical individuals from one parent.

Heredity

Transmission of traits across generations.

Variation

Differences in appearance among offspring.

Life cycle

Sequence of stages in organism's reproduction.

Genes

Units of heredity made of DNA.

Somatic cells

Human cells with 23 pairs of chromosomes.

Karyotype

Ordered display of chromosome pairs.

Sex chromosomes

Chromosomes determining individual sex (X, Y).

Gametes

Reproductive cells (sperm and eggs).

Asexual Reproduction

Single individual passes genes without gamete fusion.

Homologous Chromosomes

Chromosome pairs with similar genetic information.

X Chromosome

Female sex chromosome, present in pairs (XX).

Y Chromosome

Male sex chromosome, paired with X (XY).

Autosomes

22 pairs of non

Meiosis

Cell division reducing chromosome sets from diploid to haploid.

Meiosis I

First division stage in meiosis, separates homologous chromosomes.

Meiosis II

Second division stage in meiosis, separates sister chromatids.

Crossing Over

Exchange of genetic material between homologous chromosomes.

Synapsis

Homologous chromosomes pair during prophase I.

Independent Assortment

Random orientation of chromosome pairs in meiosis I.

Random Fertilization

Any sperm can fertilize any ovum, increasing variation.

Genetic Variation

Diversity in gene frequencies within a population.

Mutations

Changes in DNA, source of genetic diversity.

Alleles

Different versions of a gene created by mutations.

Fertilization

Union of sperm and egg to form a zygote.

External Fertilization

Sperm fertilizes eggs outside the female body.

Internal Fertilization

Sperm fertilizes eggs inside the female body.

Budding

Asexual reproduction where new individuals form from outgrowths.

Fission

Asexual reproduction by splitting a parent into two.

Fragmentation

Body breaks into pieces, each developing into adults.

Parthenogenesis

Development of an individual from an unfertilized egg.

Spermatogenesis

Continuous sperm production in males.

Oogenesis

Development of mature eggs in females.

Gonads

Organs producing gametes, testes in males, ovaries in females.

Accessory Glands

Glands secreting fluids that support sperm transport.

Semen

Fluid containing sperm and secretions from accessory glands.

Oviducts

Tubes transporting eggs from ovaries to uterus.

Uterus

Organ where embryo develops, lined with endometrium.

Vagina

Muscular chamber for sperm reception and birth canal.

Mammary Glands

Glands producing milk, important for offspring nourishment.

Hormonal Control

Regulation of reproductive cycles by hormones.

GnRH

Hormone from hypothalamus regulating FSH and LH release.

FSH

Follicle

LH

Luteinizing hormone, triggers ovulation and testosterone production.

Cortical Reaction

Egg response preventing polyspermy after fertilization.

Cleavage

Rapid cell division after fertilization, forming blastomeres.

Blastula

Early embryonic stage, a ball of cells.

Gastrulation

Formation of three germ layers in the embryo.

Embryonic Germ Layers

Ectoderm, endoderm, and mesoderm formed during gastrulation.

Amnion

Membrane surrounding the embryo, providing cushioning.

Chorion

Outer membrane involved in gas exchange.

Yolk Sac

Membrane providing nutrients to the developing embryo.