Genetics1
when an organism has two identical alleles for a particular gene, either both dominant or both recessive (e.g., AA or aa).
What is homozygous?
The process of cell division that results in two genetically identical daughter cells. It is used for growth, repair, and asexual reproduction.
What is mitosis?
An allele that is expressed in the phenotype of a heterozygous individual (e.g., Aa). Only one copy of the dominant allele is needed for the trait to be expressed.
What is a dominant allele?
A type of cell that contains a true nucleus enclosed by a membrane, as well as membrane-bound organelles. Eukaryotic cells are found in animals, plants, fungi, and protists.
Known as the powerhouse of the cell, the generate energy in the form of ATP through cellular respiration. They have their own DNA and are found in large numbers in most eukaryotic cells.
When an organism has two different alleles for a particular gene (e.g., Aa). Typically, the dominant allele will determine the trait.
What is heterozygous?
A type of cell division that produces four genetically different gametes (sperm or egg cells) with half the chromosome number of the original cell. It occurs in two stages.
What is meiosis?
An allele that is only expressed in the phenotype if two copies are present (e.g., aa). It is masked by the presence of a dominant allele in heterozygotes.
What is a recessive allele?
A simpler type of cell that lacks a true nucleus and membrane-bound organelles. DNA is free-floating in the cytoplasm. Bacteria and archaea are examples of prokaryotes.
What is a prokaryotic cell?
An organelle containing digestive enzymes that break down waste materials, cellular debris, and foreign invaders like bacteria. They are more common in animal cells.
What is a lysosome?
A unit of heredity that is transferred from a parent to offspring and is responsible for determining specific traits. Genes are made up of DNA and contain the instructions for building proteins.
What is a gene?
A term used to describe a cell that contains one complete set of chromosomes (n). In humans, haploid cells have 23 chromosomes. These cells are produced during meiosis and are essential for sexual reproduction, as they combine during fertilization.
What is a haploid?
The physical or observable traits of an organism, such as height, eye color, or blood type, which result from the interaction of the genotype with the environment.
What is a phenotype?
A type of eukaryotic cell. It has a cell wall, chloroplasts, and a large central vacuole in addition to the standard organelles found in other eukaryotic cells.
What is a plant cell?
A thread-like structure composed of DNA and proteins (histones) that carries genetic information in the form of genes. These become visible under a microscope during cell division.
What is a chromosome?
Different versions or variants of a gene that can occur at the same locus. They can be dominant or recessive and affect traits such as eye color or blood type.
What is an allele?
A term used to describe a cell that contains two complete sets of chromosomes (2n). In humans, diploid cells have 46 chromosomes, organized into 23 pairs. Most somatic cells are this, and they undergo mitosis to produce more of these cells for growth and repair.
What is a diploid?
The genetic makeup of an organism, consisting of the combination of alleles inherited from both parents. It determines the potential for certain traits to be expressed.
What is a genotype?
A type of eukaryotic cell. These cells lack a cell wall and chloroplasts but contain lysosomes and centrioles.
What is an animal cell?
A cylindrical structure made of microtubules, found in animal cells. These play a key role in organizing the mitotic spindle and separating chromosomes during cell division (mitosis and meiosis). They are typically found in pairs, within a region called the centrosome.
What is a centriole?
The specific, fixed position on a chromosome where a particular gene or genetic marker is located.
What is a locus?
One of the two identical halves of a replicated chromosome. Each chromatid is a copy of the chromosome's DNA, and they are joined together at the centromere. During cell division (mitosis or meiosis), these are separated into daughter cells, ensuring that each new cell receives an identical set of chromosomes.
What is a chromatid?
A process that occurs during Prophase I of meiosis, where homologous chromosomes pair up and exchange segments of genetic material. This leads to new combinations of genes in the gametes.
What is crossing over (genetic recombination)?
Any cell in a multicellular organism that is not a gamete. These cells make up the body's tissues and organs, including skin, muscle, and nerve cells. They are diploid in humans, meaning they contain two sets of chromosomes (one from each parent).
What is a somatic cell?
The region of a chromosome where two sister chromatids are joined together. This plays a crucial role during cell division by serving as the attachment point for spindle fibers, which pull the sister chromatids apart during mitosis and meiosis. It is also important for the proper distribution of chromosomes to daughter cells.
What is a centromere?