Idk literally all of cells Flashcards
What is the structure of the genetic material found in mitochondrion?
Singular, circular, double helix
What organelles are proof of endosymbiosis and why?
Mitochondria and chloroplasts. Because they have:
- Have 70s, like bacteria
- Have double membrane; inner membrane similar to plasma membrane on bacteria, similar size
- DNA of their own; circular like bacteria, codes for proteins, genetic sequences like bacteria
- Multiply independently, mimicking binary fission
- Antibiotics which block bacterial ribosomes also affect their ribosomes, but not those in the eukaryotic cytosol.
What organelles do eukaryotes have that prokaryotes do NOT?
- No formal nucleus
- No mitochondria
- No endoplasmic reticulum
- No golgi apparatus, so-
- No lysosomes
- No membrane-bound organelles
Why would you view a pancreatic acinar cell, which is mostly comprised of ribosomes, through an electron microscope?
Because an electron microscope has higher resolution and higher magnification than a light microscope.
For this cell particularly, you also want to focus on the ribosomes. Which you would not be able to view if it were a light microscope. Allows us to see the ultrastructure of the cell.
What organelles do prokaryotes share with eukaryotes?
*Free ribosomes
*Cytoplasm
*Plasma membrane
*Cell wall
Arrow pointing to a bacteria cell’s coils. What is it?
Nucleoid region - polyphosphate body
It contains DNA
Compare and contrast the structure of the Golgi apparatus and the rough endoplasmic reticulum
They both consist of flattened membrane areas.
The RER has ribosomes bound to it, while Golgi does not.
The Golgi has much shorter cisternae than the RER.
Part of the RER is continuous with the nuclear membrane, while the Golgi apparatus is not.
Explain the factors that limit cell size in humans
Surface area affects the rate at which material enters and leaves the cell.
Volume affects the rate at which materials are used and produced by the cell.
The surface area to volume ratio affects the rate of metabolism in a cell.
The bigger the cell is, the smaller the SA is.
Cells having a small surface area ratio cannot exchange materials fast enough, so the cell dies. It must maintain an appropriate SA to V ratio.
Some cells, like neurones or muscle cells, are long and thin, which maintain a high SA to V ratio.
How are life functions preformed by unicellular organisms
Movement, Respiration, Sensitivity, Growth, Reproduction, Excretion, Nutrition
*Movement: cilia used to propel themselves in water
*Sensitivity: response to environment, avoidance of light
*Homeostasis demonstrated by maintaining internal conditions; expelling excess water through contractile vacuoles
*Metabolism carried out by enzymes in cytoplasm
* Reproduction demonstrated by asexual divison (binary fission), amitotic division of macronucleus, or sexually through conjugation
What are features that animal and plant cells do NOT share?
Plants have a cell wall, animals do NOT
Plants have a central vacuole, animals do NOT
Plants have chloroplasts, animals do NOT
Animals have lysosomes, plants do NOT
Animals have cilia and flagella, plants do NOT
Animals have centrioles, plants do NOT
Explain how light energy is used in photosynthesis to carry out anabolic reactions?
- Light energy absorbed by chlorophyll.
- Light energy transferred to electrons
- Light energy splitting water molecules. Photolysis releases electrons for the electron transport chain. Hydrogen ions for use in ATP production.
- Light energy used to synthesize ATP from ADP and inorganic phosphates
- NADPH / ATP used to make larger organic compounds (glucose, starch)
Outline the different uses of a karyogram
A karyogram permits the visualization of the chromosomes in an organism.
- You can determine the sex of the individual (sex chromosomes are the 23rd pair)
- You can determine whether they have some condition because of trisomy (down syndrome, patau syndrome)
- You can determine whether they are missing a chromosome.
Distinguish between cells with a haploid and a diploid nuclei
- [in humans] Haploid have 23 alleles, diploid have 46
- Haploid is usually the product of meiosis, diploid is product of mitosis
- Haploid have one pair of chromosomes per type, diploid have two
- Haploid have one allele for each gene, diploid have two
- Haploid are usually gametes, diploid are usually somatic
Compare and contrast different types of chromosomes
All chromosomes made of DNA and contain genetic material.
But, they:
*differ in length.
*differ in type and number of genes.
Prokaryotic and eukaryotic chromosomes both have DNA, but:
*eukaryotic chromosomes are associated with proteins, bacterial are not.
* Prokaryotic chromosomes are looped, while eukaryotic are linear.
Autosomes and sex chromosomes contain genes, but:
*the human Y chromosome carries information mainly coding for male sex determination and development, while the X chromosome carries information for other body characteristics
*there is only one pair of sex chromosomes, while there can be multiple autosomes
*Autosomes are pairs of homologous chromosomes equal in length, while sex chromosomes can be different lengths
* chromosomes can be homologous and non-homologous
* homologous chromosomes are pairs of chromosomes of equal length carrying the same genes, but different alleles, while non-homologous chromosomes carry different genes
Outline the features of cells that do not conform to cell theory
- Mature red blood cells have no nucleus
- Striated muscle cells have multiple nuclei
- Giant algal cells can be seen without a microscope
- Fungal hyphae are multinucleate
*Phloem sieve tube elements lack nuclei, have continuous cytoplasm flowing through adjacent cells.
Compare and contrast the structures of E. Coli and a palisade mesophyll cell
They both have:
* Cell wall
* Plasma membrane
* Cytoplasm
* Ribosomes
However,
* Palisade mesophyll has 80s ribosomes, E. Coli has 70s
* Palisade mesophyll is compartmentalised, E. Coli is not.
* Palisade mesophyll has membrane-bound organelles, E. Coli does not.
* E. Coli has flagella/cilia and palisade mesophyll does not.
* E. Coli is made up of peptidoglycan, while palisade mesophyll is made of cellulose.
* E. Coli has circular and naked DNA, while palisade mesophyll has linear DNA.
* E. Coli have a nucleoid, palisade mesophyll have nuclei.
Distinguish between the structure and location of chromosomes found in prokaryotes and eukaryotes
*Eukaryotic chromosomes are found in the nucleus, whereas prokaryotic chromosomes are found in the nucleoid region
*Eukaryotic chromosomes are contained within a membrane, prokaryotic chromosomes are not membrane bound.
*Eukaryotes have linear chromosomes, prokaryotes have circular chromosomes
*Prokaryotes have one chromosomes, eukaryotes have multiple chromosomes
*In eukaryotic chromosomes, DNA is associated with histone proteins. In prokaryotes they do not have histones.
*Eukaryotes have centromeres, telomeres, and centrioles; prokaryotes do not.
Describe the stages of meiosis and how genetically unique, haploid gametes are created during the process.
What and where are the different checkpoints of the cell cycle?
Checkpoint 1: G1 going into S
It checks if the cell is growing enough, if DNA is okay, and if cell has enough resources to keep going.
Checkpoint 2: G2 going into M
It check if the cell has enough energy, nutrients, and if DNA was replicated correctly
Checkpoint 3: M phase; checks during metaphase. It checks if the chromosomes are correctly aligned and attached to the spindle in the centre of the cell to ensure no chromosome breaks off incorrectly.
What are the different phases of the cell cycle?
Interphase: stage where cell is not dividing.
G1: Cell synsthesizes the RNA, enzymes, and proteins, required for growing. Cell grows and duplicates organelles.
G0: Temporary or permanent state where cell does not divide.
S: DNA duplicated.
G2: Cell continues growing, continues synthesizing proteins, checks duplicated DNA for errors
