U5 - Cell Cycle - Biology Regents

What is DNA?

a molecule that carries genetic information for the function and development of an organism

How does the Surface Area to Volume Ratio work?

as a cell increases in size, its surface area-to-volume ratio decreases

What is cell division?

process by which a parent cell divides its nuclear and cytoplasmic components into two daughter cells

What are the two types of cell division?

Meiosis and Mitosis

What is the 4 phases for cell divison?

prophase, metaphase, anaphase, telophase

What are chromosomes?

long DNA molecule of part or all genetic material in an organism

What do chromosomes do?

carry genetic information to be passed on from one generation to the next

Where is the chromatin?

in the nucleus of eukaryotic cells

What does a chromatin do?

packages DNA into more compact and denser structure and is consisted of proteins, RNA, and DNA

What is a sister chromatid?

refers to identical copies formed by the DNA replication of a chromosome with both copies joined together by a centromere

What is a centromere?

central part of a chromosome that acts like a manager, keeping it together and making sure cells divide the DNA properly during cell division

What are the 2 major phases the cell cycle is divided into?

interphase and mitotic phase

What happens during Interphase Gap 1?

the cell grows larger and builds organelles

What happens during Interphase S?

the cell synthesizes a copy of the DNA in its nucleus while also duplicating the centromere

What is the difference in amount of daughter cells produced in cell division?

during mitosis, one cell divides into two genetically identical daughter cells as in meiosis, a single cell divides twice and produces 4 unique daughter cells

What happens during Interphase Gap 2?

the cell grows more and makes proteins & organelles, it begins to recognize its contents in preparation for mitosis

What is Mitosis?

the cell division for stomatic cells and the asexual reproduction of unicellular eukaryotic organisms

What is Meiosis?

the sex cell division for the production of gametes in sexual reproduction

What separates Meiosis?

homologous chromosomes

What separates Mitosis?

sister chromatids

What is early prophase?

chromosomes start to condense, then the miotic spindle forms and the nucleolus disappears

What is late prophase? (prometaphase)

the miotic spindle begins to capture & organize the chromosomes

they become more condense and compact

then the nuclear envelope breaks down which releases the chromosomes

the spindle grows & some of the microtubules “capture them

What do centrioles do?

produce spindle fibers that attach to the centromere of the chromosome and separate sister chromatids to opposite poles of the cell during anaphase

What does the spindle do?

divides the genetic material in a cell

Which chromosome pair does down syndrome come from?

21st pair

What are gametes?

sex cells

What happens during metaphase?

nucleus dissolves and the cells chromosomes condense and move together aligning in the center of the diving cell

What happens during Anaphase?

sister chromatids separate from each other and are pulled towards opposite ends of the cell

What happens during Telophase?

cell is nearly done dividing and it starts to re-establish its normal structures as cytokinesis takes place

What is a fertilized egg?

zygote

What is a cell plate?

a structure that forms when the cytoplasm of a plant cell divides; it separates the two sets of chromosomes during cytokinesis

What is cancer?

disease caused when cells divide uncontrollably and spread into surrounding tissues

What are stem cells?

cells that are able to develop into many different types of cells in the body

What is reduction division?

meiosis is often referred to as this b/c it reduces the # of chromosomes to half the norm

What are homologous chromosomes?

made up of chromosome pairs that are practically identical; one set from maternal and one set from paternal

What is a diploid?

presence of two complete sets of chromosomes with each parent contributing to each pair; FULL 46 CHROMOSOMES

Haploid/ Monoploid

a cell that contains a single set of chromosomes

What is Interphase?

longest phase in the cell cycle, made up of G1, S, G2

What is involved during Prophase 1?

involves separation of homologous chromosomes

What is involved during Prophase 2?

involves separation of sister chromatids

What is synapses?

pairing of homologous chromosomes during prophase

What is a tetrad?

a group of 4 chromatids that are formed during meiosis 1 and are a result of the duplication of chromosomes

What is Metaphase 1?

pairs of homologous chromosomes line up at the equatorial plate

What is Metaphase 2?

single chromosomes that aren’t paired up that line up at the middle of the cell

What does the term Crossing-Over mean?

the exchange of DNA between paired homologous chromosomes that occurs during development of egg & sperm cells

What happens during Anaphase 1?

the homologues are pulled apart and move apart to opposite ends of the cell

What happens during Anaphase 2?

the sister chromatids separate and are pulled towards opposite poles of the cell

What is disjunction?

the normal separation of chromosomes toward opposite poles of the cell during cell division; often occurs during Anaphase 1&2

What is Non-Disjunction?

a pair of homologous chromosomes has failed to separate at anaphase so now both chromosomes of the pair cannot pass them onto the same daughter cell

What is cytokinesis?

divides cytoplasm of parental cells into 2 daughter cells

What is so important about cytokinesis?

to separate the cell in half and ensure that one nucleus ends up in each daughter cell

What happens in Telophase 1?

the homologous chromosomes separate and the sister chromatids stay intact + the 2 cells produced from t1 are both diploid

What happens in Telophase 2?

the sister chromatids are separated into two new nuclei + this forms 4 genetically different haploid daughter cells