Biology Flashcards
Chromosomes
Thread-like structures found in the nucleus of cells that are made of DNA and protein.
What happens at the start of mitosis? ie. Interphase
Chromosomes replicate and become double-stranded.
What happens in the second stage of mitosis? ie. Prophase
Double-stranded chromosomes become visible.
What happens in the third stage of mitosis? ie. Metaphase
Double-stranded chromosomes line up along the equator of the cell.
What happens in the fourth stage of mitosis? ie. Anaphase
Chromosomes move to opposite ends of the cell.
What happens in the fifth stage of mitosis? ie. Telophase
Two nuclei form, each with a diploid number of chromosomes.
What happens in the end of mitosis?
Membranes form separating the two nuclei into two daughter cells.
What is the human genome project?
It was an international project that aimed to identify all genes 20 000- 25000 genes in the human genome, and determine the sequence of the 3 billion base pairs that make up human chromosomes.
What is the process of gene testing?
Scientists are able to test for a gene once its function in is known. This could help you avoid diseases that are controlled by lifestyle as well as genetics, such as the risk of heart disease or type-2 diabetes.
What does gene therapy do?
It has the potential to cure genetic diseases. In gene therapy, the defective gene is replaced with a normal gene.
What is a fossil?
The preserved evidence in rocks or soils of organisms that once existed on Earth.
Why is replication important?
The cell cycle is necessary for replacing dead or damaged cells. It is especially important in tissues such as skin and hair.
What is the fossil record?
A list showing all the species of living organisms that have been found as fossils as well as their location and age.
What is DNA?
The molecule that determines the genetic characteristics of most living things.
What is a Mendelian trait?
Where one gene accounts for one trait.