Biology Questions and Answers with Complete Solutions

Biology Questions and Answers with Complete Solutions Which pair includes a phase of the cell cycle and a cellular process that occurs during that phase? G2 phase, preparation for mitosis The two main stages of cell division are called mitosis and cytokinesis. Which of the following is a correct statement about the events of the cell cycle? Interphase consists of the G1, S, and G2 phases. During normal mitotic cell division, a parent cell that has four chromosomes will produce two daughter cells, each containing four chromosomes. During which phase of mitosis do the chromosomes line up along the middle of the dividing cell? metaphase When during the cell cycle is a cell's DNA replicated? S Phase What is the role of the spindle fibers during mitosis? They help separate the chromosomes When during the cell cycle are chromosomes visible? only during cell division prophase The first phase of mitosis is called cell division on chart left side (D) During which phase in the cell cycle does mitosis happen? M phase What causes cells to lose their ability to control growth? Smoking, exposure to radiation, viral infections Surgery, Radiation, Chemotherapy Treatment Cytoplasm divides...forming two new cells Happens right after Mitosis Cytokinesis Chromosomes gather at opposite ends of the cell Chromosomes lose their distinct shapes Spindle fibers break down Two new nuclear envelopes will form Telophase Sister chromatids separate into individual chromosomes Sister chromatids are moved apart -Spindle fibers move them Anaphase Chromosomes line up across the center of the cell -Each arm of chromosome - sister chromatid -Connection point-centromere Each chromosome is connected to a spindle fiber (structure that helps separate the chromosomes) at its centromere Metaphase First and longest phase of mitosis Chromosomes become visible as Xs Centrioles (two tiny organelles in the cytoplasm) separate Near the end of prophase....... Nuclear envelope (surrounds the nucleus) breaks down Prophase The division of the cell nucleus -Cell's DNA organized in chromosomes Occurs ONLY in eukaryotes The process of creating a multi-celled organism Cell>Tissue>Organ>Organ System>Organism Muscle Cell>Muscle Tissue>Stomach>Digestive System>Ox Steps of mitosis (PMAT) Prophase, Metaphase, Anaphase, Telophase Mitosis G1 G2 and S Interphase Immediately follows G₂ Produces 2 daughter cells from 1 'parent' cell "Mitosis" Cell Division M Phase Immediately follows S phase Shortest phase Organelles produced to prep cell to divide Preparation for Mitosis G2 Immediately follows G₁ phase DNA is copied Same thing as saying: chromosomes copy themselves Cell still hasn't divided, so there is double the amount of DNA in the cell DNA replication S Phase During this phase, cells.. -Increase in size -Create proteins (during protein synthesis) -Make organelles Cell Growth G1 Phase G₁ (cell growth) S (DNA replication) G₂ (preparation for mitosis) M (cell division: mitosis & cytokinesis) Eukaryotic Cell Cycle the point where two chromatids attach to one another Centromere the two exact copies of DNA that make up each chromosome (often called sister chromatids) Chromatids a structure containing coiled DNA and proteins Chromosome chromatid centromere chromosome structure Carry genetic information -Passed on from one generation to the next Chromosomes are made of DNA All organisms have a different number of chromosomes -Humans have 46 chromosomes in every cell chromosomes 1. The larger the cell becomes, the more demands on its DNA 2. 2. The cell has more trouble moving enough nutrients & wastes across the cell membrane -like water and salts limits to cell growth