2nd test Flashcards
What is the Cell Theory?
All living things are made of cells.
Cells are the basic units of structure and function in living things.
Living cells come only from other living cells.
Are viruses are alive or dead?
Viruses are not classified as being alive because they don’t have their own machinery for reproducing. They can only take over the machinery of cells, turning them into virus factories.
How are prokaryotes different from eukaryotes? Give examples of each?
The main difference between prokaryotic and eukaryotic cells is that eukayrotic cells have a nucleus and membrane-bound organelles, while prokaryotic cells lack these structures. Prokaryotic cells are the simplest of all living things, and they only exist as unicellular bacteria. All multicellular organisms and higher-order bacteria are comprised of eukaryotic cells.
Nucleus
large membrane-enclosed structure that contains cell’s genetic material in form of DNA; controls many of the cell’s activities
Chloroplasts
organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it to chemical energy
Mitochondria
cell organelle that converts the chemical energy stored in food into compounds that are more convenient for the cell to use
Endoplasmic Reticulum
internal membrane system in cells in which lipid components of the cell membrane are assembled and some proteins are modified
Vacuoles
cell organelle that stores materials such as water, salts, proteins, and carbs
Explain the differences between metaphase I in meiosis and metaphase in mitosis
The Metaphase stage found in meiosis I is called the Metaphase I. In here, the pairs of chromosomes began to arrange on the Metaphase plate and then they bind to the meiotic spindle. At this moment, the centrioles can be seen at the opposite poles of the dividing cell. The pairs of chromosomes get attached to the spindle fibers from each pole, at the opposite sides.
The Metaphase II is found in meiosis II, and it is very similar to the Metaphase found in mitosis I. In this step too chromosomes get arranged on the Metaphase plate and are attached to the completed spindle.
Gene
The fundamental, physical, and functional unit of heredity. (Also known as factor)
Allele
One member of a pair (or any of the series) of genes occupying a specific spot on a chromosome (called locus) that controls the same trait.
Chromosomes
is a long, stringy aggregate of genes that carries hereditary information and is formed from condensed chromatin.
chromatid
Either of the two strands joined together by a single centromere, formed from the duplication of the chromosome during the early stages of cell division and then separate to become individual chromosome during the late stages of cell division.
centromere
The constricted region joining the two sister chromatids that make up an X-shaped chromosome.
domanint
In genetics, the dominant is the one that determines the phenotype of an organism. Its effects are readily recognized than the effects of the recessive. Usually, a dominant allele is symbolized with a capital letter and the recessive allele a small letter, for example: Hh (where H refers to the dominant allele while h to the recessive allele).
