test 3 Flashcards
(55 cards)
What is cell division?
- The ability of organisms to produce more of their own kind is the one characteristic that best distinguishes living things from nonliving matter.
What is genome
- A cell’s genetic information, packaged as DNA, is called its genome.
difference between chromatin, chromosome, and chromatid
- DNA molecules are packaged into chromosomes.
- Every eukaryotic chromosome consists of one long, linear DNA molecule associated with many proteins. the complex is referred to as chromatin.
Each duplicated chromosome consists of two sister chromatid
How are somatic cells and gametes different
Human somatic cells (all body cells except sperm and egg) have 46 chromosomes,
Human reproductive cells or gametes (sperm or eggs) have one set of 23 chromosomes
What are mitosis and cytokinesis
Mitosis, the division of the nucleus, is usually followed by the division of the cytoplasm
Cytokinesis usually starts during the later stages of mitosis, and the spindle eventually disassembles by depolymerization of microtubules.
Cytokinesis divides the cytoplasm
What are the phases of the cell cycle
G1 phase, S phase, G2 phase, and M phase (mitosis phase
What is the correct order for the phases of the cell cycle?
G1, S, G2, and then M (mitosis) phase
During what sub-phase of the cell cycle is DNA replicated
S phase (Synthesis phase) of Interphase
What is the kinetochore
a kinetochore, a specialized protein structure located at the centromere.
How is cytokinesis in an animal cell different from cytokinesis in a plant cell
In animal cells, cytokinesis occurs by a process called cleavage.
During telophase, vesicles from the Golgi apparatus move along microtubules to the middle of the cell, where they coalesce to form a cell plate.
Cell wall materials carried in the vesicles collect in the cell plate as it grows.
The plate enlarges until its membranes fuse with the plasma membrane at the perimeter.
The contents of the vesicles form new cell wall material between the daughter cells.
What are the stages of mitosis?
prophase, prometaphase, metaphase, anaphase, and telophase.
What happens to the chromosomes in each stage of mitosis
- As the chromosomes condense, the region where the chromatids connect shrinks to a narrow area, made up of two centromeres.
What is binary fission? Which organism uses binary fission?
cell division called binary fission,
How do cyclins and kinases controls the cell cycle?
Cyclins are proteins that regulate the cell cycle by activating cyclin-dependent kinases (CDKs
The kinases that drive the cell cycle are present at constant concentrations but require the attachment of a second protein, a cyclin, to become activated.
What is cancer
Cancer cells do not stop dividing when growth factors are depleted.
What is difference between a benign tumor and a malignant tumor?
If the abnormal cells remain at the originating site, the lump is called a benign tumor
A malignant tumor includes cells whose genetic and cellular changes enable them to spread to new tissues and impair the functions of one or more organs.
An individual with a malignant tumor is said to have cancer.
What is metastasis
What is metastasisCancer cells are abnormal in many ways
How do density-dependent inhibition and anchorage dependence differ between normal cells
and cancer cells
Cultured cells normally divide until they form a single layer on the inner surface of the culture container. If a gap is created, the cells will grow to fill the gap.
The binding of a cell-surface protein to its counterpart on an adjoining cell sends a growth-inhibiting signal to both cells, preventing them from moving forward in the cell cycle, even in the presence of growth factors.
To divide, the cells must be anchored to a substratum, typically the extracellular matrix of a tissue.
Experiments suggest that, like cell density, anchorage is signaled to the cell cycle control system via pathways involving plasma membrane proteins and elements of the cytoskeleton linked to them.
What is Genetics
Genetics is the scientific study of heredity and hereditary variation.
How are asexual reproduction and sexual reproduction different
Asexual reproduction is a method of reproduction that creates offspring that are genetically identical to a single parent
it involves the fusion of genetic material from two parents, creating offspring that are genetically unique
what is a clone?
clone, a group of genetically identical individuals.
What are homologous chromosomes?
Homologous chromosomes appear to be alike, but they may have different versions of genes, each called an allele, at corresponding loci
What is a karyotype? What are sex chromosomes versus autosomes
Images of the 46 human chromosomes can be arranged in pairs in order of size to produce a karyotype display
Sex chromosomes determines an individual’s sex. Human females have a homologous pair of X chromosomes (XX); males have one X and one Y chromosome (XY).
The other 22 pairs of chromosomes are called autosomes.
The occurrence of homologous pairs of chromosomes is a consequence of sexual reproduction.
What is meiosis
Meiosis is a type of cell division that produces gametes (sperm and egg cells) in sexually reproducing organisms.