BIO Final Exam Study Guide

A series of flashcards covering key concepts related to photosynthesis, cellular reproduction, genetics, molecular biology, and biotechnology for exam preparation.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.

Photoautotroph

Organisms that use light energy to convert carbon dioxide and water into organic materials.

Chloroplast

A structure in plant cells where photosynthesis takes place.

Thylakoid

A membrane-bound compartment inside chloroplasts, often stacked in structures called grana.

Calvin Cycle

A series of biochemical redox reactions that take place in the stroma of chloroplasts in photosynthetic organisms.

Cytokinesis

The process of cell division that results in the separation of the cytoplasm into two daughter cells.

Cyclins

Regulatory proteins that control the progression of the cell cycle.

Meiosis

A type of cell division that produces four haploid cells, each with half the number of chromosomes of the original cell.

Homologous chromosomes

Chromosome pairs, one from each parent, that are similar in shape, size, and genetic content.

Polygenic inheritance

A mode of inheritance in which multiple genes determine the phenotype of a trait.

DNA ligase

An enzyme that facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.

Transcription

The process of copying a segment of DNA into RNA.

Restriction enzymes

Proteins that cut DNA at specific sequences, used in various biotechnological applications.

Recombinant DNA

DNA molecules formed by laboratory methods of genetic recombination to bring together genetic material from multiple sources.

Genomic DNA

The total DNA content of an organism, including both the coding and non-coding sequences.

Codon

A sequence of three nucleotides that together form a unit of genetic code in a DNA or RNA molecule.

Anticodon

A sequence of three bases on tRNA that is complementary to a corresponding codon in mRNA.

Gel electrophoresis

A laboratory method used to separate mixtures of DNA, RNA, or proteins according to their size.

Autotroph

An organism that produces its own food from inorganic substances, using light or chemical energy.

Grana

Thylakoid Stacks

Stroma of the Chloroplast

Where sugars are made

Stomata

The structure used to exchange CO2 and O2

Mesophyll Cells

specialized Photosynthesis cells in leaves

Light energy conversion

The process by which plants convert sunlight into chemical energy during photosynthesis, primarily occurring in chloroplasts.

Pigments in Photosynthetic plants

absorb light wavelengths to power photosynthesis

Structural similarities of chloroplasts and mitochondria

Both have their own DNA and a double membrane. Both have inner membranes that have ETC

Do all leaf cells contain chlorophyll?

No

Reactants of Photosynthesis

CO2, H2O, Light Energy

Chlorophyll

reflects or transmits green light

Waste product is oxygen, where does it come from?

It comes from the splitting of water molecules (photolysis)

What is the source of energy?

Sunlight

Chlorophyll a vs. b

They absorb different wavelengths of light to broaden the spectrum used for energy

What happens to water molecules during the light reactions?

Water is split to provide electrons, releasing O2 and H+ ions

What happens during carbon fixation?

Inorganic CO2 is attached to an organic molecule (RuBP) by the enzyme Rubisco

Phases of the Cell Cycle in Order

Interphase (G1, S, G2) and Mitotic Phase (Mitosis and Cytokinesis)

What is the cell cycle?

An ordered sequence of events for cell growth and division

What happens during cytokinesis?

the physical division of the cytoplasm into two daughter cells

What is a characteristic of cancer cells?

Uncontrolled cell division/loss of cell cycle regulation

What kind of regulators are cyclins and cyclin-dependent?

They are positive regulators (they promote progress to the next stage)

What stage of mitosis is a checkpoint for chromosomal abnormalities?

The M checkpoint (spindle)

What separates during anaphase?

sister chromatids pull apart

What do the microtubles of the spindle apparatus atttach to?

kinetochores

DNA Replication

S Phase of interphase

Where is DNA found in a prokaryotic cell?

The nucleoid region

What happens during S phase?

DNA synthesis (replication)

What kind of DNA do prokaryotic cells exchange?

plasmids through conjugation

Fertilization (syngamy)

The fusion of haploid cells

Which life cycle contains a unicellular haploid stage?

All three major multicellular life cycles (diplontic, haplontic, and alternation of generations) feature a unicellular haploid stage, gametes or spores

How is the ploidy different in daughter cells produced by mitosis and meiosis?

Mitosis produces diploid (2n) daughter cells (genetically identical to the parent), while meiosis produces haploid (n) daughter cells (genetically unique)

What kind of cells are produced during meiosis?

gametes (sperm and egg cells in animals) or spores (in plants/fungi)

What are homologous chromosomes?

a pair of chromosomes (one from each parent) that are the same length and contain the same genes in the same locations, though they may have different alleles

What happens to the amount of DNA/chromosomes during meiosis?

the amount of dna is reduced by half (from diploid to haploid) through one round of replication followed by two rounds of division

What happens before meiosis I?

Interphase, specifically the S phase,

Chlorophyll A

Primary reaction center pigment that initiates light reaction

Chlorophyll B

Accessory pigment that passes energy to chlorophyll

What is the first step of the light reactions?

Photoactivation of PSII.

Photoactivation of PSII.

Pigments absorb light energy, exciting electrons in Photosystem II to a higher energy state

How are electrons replaced in Photosystem II?

Photolysis

Photolysis

Water molecules are split into electrons, hydrogen ions (H+) and oxygen gas (O2)

What happens as electrons move through the first Electron Transport Chain?

Proton pumping

Proton pumping

the energy from the moving electrons is used to pump H+ ions into the thylakoid lumen, creating a concentration gradient

How is ATP energy generated during the light reactions?

Chemiosis

Chemiosis

H+ ions flow through ATP synthase, providing the energy to convert ADP into ATP

What occurs when electrons reach photosystem I (PSI)

Re-energization

Re-energization

light is absorbed again, boosting the electrons back to a high level