Topic 2 Flashcards
Structures found in living cells that contain the genetic material
Chromosomes
Leads to the production of two cells with the same number of chromosomes as the parent cell
Mitosis
Reduces the genetic content and number of chromosomes into half of the original
Meiosis
Defines the cell boundary and delimits the cell from its external environment
Plasma membrane
The cell wall of plants is made up of?
Cellulose
Provides biochemical identity at the surface of cells
Glycocalyx
Act as recognition sites that transfer specific chemical signals across the cell membrane to the cell
Receptor molecules
Have “true nucleus”
Eukaryotic
The entirety of the cell within the plasma membrane excluding the nucleus
Cytoplasm
Support structure of cell, Maintains cell shape, facilitates mobility, anchors various organelles
Cytoskeleton
Serves as the site for fatty acid and phospholipid synthesis
Smooth Endoplasmic reticulum
Contains ribosomes
Rough endoplasmic reticulum
Where genetic information from mRNA is translated into proteins
Ribosomes
Performs ATP synthesis during cell respiration
Mitochondria
found in plants, algae and some protozoans; Performs photosynthesis
Chloroplast
Associated with the organization of spindle fibers that function in mitosis and meiosis
Centrioles
A field of genetics that involves the microscopic examination of chromosomes
Cytogenetics
An organized representation of chromosomes in a cell
Karyotype
It has two sets of chromosomes
Diploid cell
One-half of the diploid number
Haploid cells
A constricted region whose location establishes the general appearance of each chromosome
Centromere
What are the four classification of chromosomes based on the position of centromere
Telocentric
Acrocentric
Sub-metacentric
Metacentric
“petite” , shorter arm in chromosomes
p arm
longer arm below the centromere in chromosomes
q arm
Members of a pair of chromosomes
Homologs
True or False
Many bacteria and viruses have one chromosome
True
It mask the expression of recessive alleles
Dominant
Eye color; located in chromosome 15; results in blue or brown eyes
OCA2
True or false
The sequence of bases usually differs by less than 2%
False (1% only)
Carries the same allele
Homozygous
Carries different alleles
Heterozygous
Physical location of a gene
Locus
Inheritance from two parents. One set coming from the maternal parent and the other from the paternal parent
Biparental Inheritance
XX Chromosome
Female
XY Chromosome
Male
In ________________, the mother cell is one individual and the daughter cells are two new separate organisms
Unicellular organisms
A process that does not involve genetic contribution from two different gametes
Asexual reproduction
Produce two daughter cells that have the same number and types of chromosomes as the mother cell
Eukaryotic cell division
A series of phases that aims to divide eukaryotic cells
Cell cycle
Consist of the G₁, S and G₂ phases
Interphase
Critical periods that involve many molecular changes
Gap phases
Preparation to divide
May accumulate molecular changes and reach a restriction point that leads to cell division
Gap 1 phase
True or False
In the case of terminally differentiated cells, they will never divide again
True
When cells temporarily do not advance through the rest of the cycle
Gap 0 phase
Chromosome replication
Synthesis (S) phase
A group of proteins bound to the centromere and holds the chromatids together
Kinetochore
Accumulation of materials necessary for nuclear and cell division
Gap 2 phase
Distribute the replicated chromosomes, divide one nucleus into two, give each daughter cell the complementary chromosomes
M Phase (Mitosis)
formation of two daughter cells
Cytokinesis
Structures found in eukaryotic cells from which microtubules originate
Microtubule-organizing centers (MTOCs)
formed from the rapid polymerization of tubulin proteins
Microtubules
Contains a pair of centrioles that form a right angle with each other.
Found in animal cells but NOT in all eukaryotic cells
Centrosomes
3 types of microtubules
Aster
Polar
Kinetochore
Emanate outward from the centrosome toward the plasma membrane
Aster microtubules
Project toward the region where the chromosomes are found during the mitosis (between the spindle poles)
Polar Microtubules
A microtubule that have attachments to the kinetochores
Kinetochore microtubules
Phases in Mitosis
Prophase
Prometaphase
Metaphase
Anaphase
Telophase
Replication of chromosomes into chromatids joined as sister chromatids
Prophase
A multi-subunit protein complex that holds the sister chromatids together
Cohesion
-Movement of centrosomes to opposite ends
-Interaction of spindle fibers with the sister chromatids
-Attachment of kinetochore microtubules
Prometaphase
Sister chromatids align along the metaphase plate
Metaphase
-Sister chromatids are separated as an individual chromosome
-Movement of chromosomes to opposite poles
Anaphase
Chromosomes reach their respective poles
Telophase
-Two nuclei are separated to daughter cells
-Segregation of cell organelles
Cytokinesis
Myosin hydrolyzes ATP that shortens the ring to form a _______
Cleavage furrow
This structure forms shortly after the Anaphase in plant cell mitosis
Cell plate
Production of haploid cells that contain a single set of chromosomes from a diploid cell
Meiosis
True or false
Meiosis involves two successive division
True ( Meiosis I and Meiosis II)
5 Stages of Prophase I
Leptotene
Zygotene
Pachytene
Diplotene
Diakinesis
The replicated chromosomes begins to condense and become visible with a light microscope
Leptotene
The recognition process that happens in Zygotene
Synapsis
It promotes the binding of homologs to each other
Synaptonemal complex
Homologs become completely aligned
Pachytene
Contains two pairs of chromatids
Bivalent
Physical exchange of chromosome pieces that result in exchange of genetic information
Crossing over
The connection resulting from the crossing over
Chiasma (Chiasmata)
Disappearance of synaptonemal complex, chromatids pull apart slightly
Diplotene
Synaptonemal complex completely disappears
Diakinesis
What happens at Prometaphase I
Nuclear membrane disappears
Formation of spindle fibers
Chromosomes begins to move
The pairs of sister chromatids are aligned in a double row
Metaphase I
The two sister chromatids separate from each other
Anaphase I
What happens at Telophase I and Cytokinesis
-Sister chromatids reach their respective poles
- Decondensation occurs
- Nuclear membranes reforms to produce two separate nuclei
- Reduction division
- Haploid cells that do not have pairs of homologous chromosomes
Meiosis II is similar to Meiosis I but with different starting point
False (Mitosis)
The process where gametes are made in such a way that they contain half the amount of the organisms genetic material
Sexual Reproduction
The process of producing gametes
Gametogenesis
Gametes are morphologically similar
Isogamous
Produce two morphologically different types of gametes
Heterogamous
Production of sperm, occurs in the testes
Spermatogenesis
Part of a sperm that contain digestive enzymes
Acrosome
A part of sperm that contains many mitochondria
Collar
Production of egg cell
Oogenesis
Oogenesis occurs within a specialized diploid cell of the ovary
Ooginia
A process that starts in puberty
Spermatogenesis
A process that begins in fetus
Oogenesis
In alteration of generation, meiosis produces haploid cells called
Spores
It can lead to chromosomal abnormalities including non disjunction and polyploidies
Errors in Meiosis
Occurs when chromosomes fail to separate appropriately
Non-disjunction
Occurs when there are more than 2 copies of a homologous chromosome in a cell
Polyploidy
What chromosome causes Down Syndrome
Trisomy 21
