Exploring Eukaryotic Cell Structure and Function

Organisms with cells containing a true nucleus

1,800 million years ago

10-100µm

Plasma membrane

Physarum polycephalum

Haplontic life cycle

Dinoflagellates

Lichen

Trichomonas vaginalis

Heterozygote advantage and higher frequency of the “S” allele

Lingulodinium polyedra

Choanoflagellate

Protein synthesis

Nucleus

Digesting macromolecules

Mitochondria

Degradation of hydrogen peroxide

Eukaryotic flagella have a different structural composition

Presence of chloroplasts

Golgi apparatus

Providing structural support

Protists

It involves the production of haploid cells through meiosis.

Mitochondrion

Trichomonas vaginalis

Haplontic life cycle

Heterozygote advantage and higher frequency of the “S” allele in those regions

Dinoflagellates

Symbiosis

Break down fatty acids and detoxify harmful substances

The structure of microtubules in the flagella

Increases genetic diversity and allows for adaptation to changing environments

The cytoplasm consists of cytosol, organelles, and inclusions, excluding the nucleus.

The Golgi apparatus modifies and traffics proteins and phospholipids.

Peroxisomes transfer hydrogen atoms and degrade hydrogen peroxide, while lysosomes digest macromolecules.

Flagella are cellular appendages specialized for locomotion.

Photosynthetic eukaryotes have mitochondria and plastids, including chloroplasts for photosynthesis.

Eukaryotes show structural variation and the presence or absence of organelles, with differences among animal cells, plant cells, and fungi cells.

Protists are a paraphyletic group of eukaryotes, including unicellular, colonial, or multicellular organisms with diverse nutrition and reproduction.

Sexual reproduction in eukaryotes involves the production of haploid reproductive cells through meiosis and the advantages and disadvantages of genetic recombination.

The endoplasmic reticulum includes rough ER for protein synthesis and smooth ER for lipid synthesis and detoxification.

Mitochondria perform cellular respiration and have their own DNA.

The cytoskeleton provides mechanical, structural, and transport functions.

Eukaryotes show structural variation and the presence or absence of organelles, with differences among animal cells, plant cells, and fungi cells.

The evolution of multicellularity and sexual reproduction were key innovations that allowed for increased complexity, specialization of cells, and genetic diversity, leading to the success and adaptability of eukaryotic organisms.

Sexual reproduction allows for genetic diversity and the shuffling of genetic material, promoting adaptability and evolutionary success. Asexual reproduction allows for rapid population growth and efficient transmission of favorable traits in stable environments.

The three types of life cycles in eukaryotes are haplontic (dominant haploid phase), diplontic (dominant diploid phase), and alternation of generations (both haploid and diploid phases are multicellular).

A mutualistic beneficial relationship between a fungus and a plant involves mycorrhizal associations, where the fungus provides the plant with increased nutrient uptake in exchange for carbohydrates. A mutualistic beneficial relationship between a fungus and an algae forms lichens, where the fungus provides a protected environment and minerals for the algae, while the algae provide organic nutrients through photosynthesis.

The evolution of multicellularity allowed for increased specialization and division of labor among cells, leading to more complex organisms. Sexual reproduction introduced genetic diversity and the potential for beneficial mutations, enhancing the adaptability and survival of eukaryotic species.

Sexual reproduction allows for genetic diversity and the potential for beneficial mutations, increasing adaptability and survival. Asexual reproduction can lead to rapid population growth and is less energy-intensive compared to sexual reproduction.

Individuals with sickle cell anemia who are heterozygous (carry one copy of the sickle cell trait) have a survival advantage against malaria. The presence of the sickle cell trait makes it more difficult for the malaria parasite to complete its life cycle within red blood cells, providing protection against severe malaria infections.

A mutualistic beneficial relationship between a fungus and a plant is exemplified by mycorrhizae, where the fungus provides increased nutrient absorption for the plant while receiving carbohydrates in return. An example of a mutualistic relationship between a fungus and an algae is lichen, where the fungus provides a protective environment and mineral absorption for the algae, while the algae provides organic nutrients through photosynthesis.

The endoplasmic reticulum (ER) is involved in the synthesis and transport of proteins and lipids. Rough ER is studded with ribosomes and is primarily responsible for protein synthesis, while smooth ER is involved in lipid synthesis and detoxification.

Mitochondria are responsible for cellular respiration, ATP production, and have their own DNA.

Sexual reproduction in eukaryotes involves genetic recombination, leading to genetic diversity and the potential for adaptation to changing environments.

Lysosomes are responsible for digesting macromolecules and cellular waste.

The three types of life cycles in eukaryotes are haplontic, diplontic, and alternation of generations. Haplontic involves a dominant haploid stage, diplontic involves a dominant diploid stage, and alternation of generations includes both haploid and diploid multicellular stages.

The main structural difference is that eukaryotic flagella have a '9+2' microtubule arrangement, while prokaryotic flagella have a different structure.

The evolution of multicellularity and sexual reproduction in eukaryotes has contributed to increased complexity, diversity, and adaptability of eukaryotic organisms.

The Golgi apparatus modifies, sorts, and packages proteins and lipids for transport within or outside the cell.

The genetic material is primarily located within the nucleus, in the form of chromosomes made of chromatin.

Mitochondria contain their own DNA and are similar to prokaryotic cells in this aspect.

Protists are a paraphyletic group of eukaryotes due to their diverse nature and the absence of a common ancestor for all protists.

Myxomycetes (slime molds) have the primary function of synthesizing pigments, producing spores, and being almost immortal.

Eukaryotic cells show structural variation, with differences in the presence or absence of organelles. For example, plant cells have cell walls and chloroplasts, while animal cells lack these features.

The significance of Dinoflagellates possessing two flagella is their ability to bloom, leading to 'Red tide' with explosive population growth, which can be triggered by coastal upwelling of nutrients and changes in environmental conditions.

Lichen is a symbiotic association between green algae and a fungus, functioning as a mutualistic relationship where the algae provide nutrients through photosynthesis, and the fungus provides a protected environment and absorbs water and nutrients from the environment.

The primary function of Choanoflagellates in relation to their single posterior flagellum and chitin in their cell walls is for propulsion and structural support, respectively, similar to the functions of flagella in many animals.

Plasmodium has a haplontic life cycle and is transmitted by mosquitos, causing malaria, with the unique function of infecting host cells and replicating within them, leading to the symptoms of the disease.

Diatoms are distinguished by their hard walls made of silica (SiO2), which provides protection and structural support, allowing them to thrive in various aquatic environments.

The increase in surface area for diffusion and longer lifespan in eukaryotic cells is significant for improving nutrient exchange and cellular function, contributing to the specialization of cells into different types and the formation of tissues and organs.

The primary function of Penicillium is to inhibit bacterial growth, as demonstrated by Fleming in 1929, showing its potential as a source of antibiotics and its role in ecological balance by controlling bacterial populations.