Question | Answer |
Define Chromosomes | in eukaryotic cells, a structure in the nucleus made up of DNA and protein; in prokaryotic cells, the main ring of DNA |
Homologous chromosomes | chromosomes that have the same sequence of genes and the same structure, they pair up together |
Describe mitosis. Which cells does it happen in? | a process of cell division that forms two new nuclei, each of which has the same number of chromosomes. happens in eukaryotic cells |
What is binary fission? What type of cells does it happen in? | is when a bacteria cell splits into two parts and each has a copy of the circle of DNA. Happens in prokaryotic cells. |
What is the cell cycle? What does it result in eukaryotic cells? | life cycle of a cell, from when it is formed to when it divides; produces more cells |
List the steps of the cell cycle in order. | Interphase, Mitosis (prophase, metaphase, anaphase, telophase), Cytokenesis |
What happens in interphase? | cell grows, chromosomes (containing DNA) and organelles are copied |
What are chromatids? | what the two copies of chromosomes are called after they are duplicated in interphase |
What is the centromere? | Where the chromatids are held together during interphase |
What happens in prophase? | chromosomes condense from long strands into rod-like structures, each has two identical copies called chromatids |
complex eukaryotes have _____ chromosomes than simpler ones | more or less, it varies |
What happens in metaphase? | The chromosomes line up at equator of the cell and nuclear membrane fully dissolves |
What happens in anaphase? | The chromatids separate into two groups and move to opposite sides of the cell |
What happens in telophase? | A nuclear membrane forms around each set of chromosomes . chromosomes unwind, mitosis is complete |
What happens in Cytokenesis in cells without a cell wall? | The division of cytoplasm
the cell pinches in two, so two new cells form, each with their own DNA |
What happens in Cytokenesis in cells with a cell wall? (plant cells) | A cell plate forms in the middle of the cell
The cell splits into 2 and the plate is replaced by a cell wall, separating the 2 new cells |
What is a cell plate? | contains material for the new cell walls and membranes |
Who was Gregor Mendel? What did he discover? | An Autralian monk who performed pea plant experiments at a monastery.
Discovered the principles of heredity. |
What is a characteristic? Give an example. | a feature that has different forms in a population
ex. Hair color |
What is a trait? Give an example | the different forms of a characteristic
ex. brown hair |
What are dominant traits? | the trait seen in the first generation when parents that have different traits reproduce |
What are recessive traits? | the trait not seen in the first generation but appears in the second when parents that have different traits reproduce |
What is heredity? | passing of traits from parents to offspring |
What is self-pollination? | when pollen from the anther of a flower fertilizes the ovule of the same flower |
What is cross-pollination? | pollen from the anther of one plant fertilizes the ovule of a flower on a different plant |
How is pollen transferred in cross-pollination? | Carried by insects
Carried by wind |
What is a true breeding plant? | A plant whose offspring will have all the same traits when it self pollinates |
Why was it important that Mendel's plants could both self-pollinate and cross-pollinate | Because if they self pollinate they are true-breeding, and Mendel could be sure of the traits that their offspring would have
Cross pollination was important because he cross pollinated the pea plants to test heredity |
What is a hybrid? | the offspring of two plants from different species |
What are genes? Give an example | physical part in the chromosome that determines the instructions for an inherited trait
ex. Bb |
What is an allele? Give an example. | different forms of a gene, the physical part of the chromosome that decides a trait ex. B |
What is a Genotype? Give an example. | the instructions based on the genes for a trait Ex. Bb |
What is a Phenotype? | the physical appearance of the trait of the organism based on the genotype |
What is Incomplete dominance? | when traits don’t blend together, but each allele has its own degree of influence |
What influences traits besides genes? Give an example. | The environment. ex. Genes may include tall, but healthy diet is required to reach full potential height |
How did Mendel do his experiment? | 1. He took removed the anthers of a pea plant so it could not self pollinate
2. He took pollen from another plant and fertilized it
3. Then he observed the offspring it produced |
What did Mendel find from his experiments? | For all of the traits, there was a dominant allele and a recessive allele. The dominant one showed up in the first generation of offspring
the recessive allele showed up in the second generation |
What was the ratio of dominant to recessive alleles in the second generation? | 3:1 |
What is a homozygous genotype? | An organism whose trait has both recessive alleles or both dominant |
Cells need to produce new cells in order to... | replace cells that have died |