Biology 1,2 UNIT 4 VOCABULARY Lesson 4.1

DNA (deoxyribonucleic acid): a double stranded nucleic acid that carries the genetic information in the cell and is capable of self-replication

nucleotide-monomer of nucleic acids consisting of a 1) phosphate group 2) sugar and 3) nitrogen base

double helix- term used to describe the “twisted ladder” shape of a DNA molecule

covalent bond- a strong chemical bond that involves sharing a pair of electrons between atoms in a molecule (such as the bond between sugar and phosphate in DNA)

hydrogen bond- weak chemical bond in which a hydrogen atom of one molecule is attracted to another atom such as a nitrogen or oxygen atom

Shared Electrons

Lesson 4.2 complimentary base pairing- matching of nucleotides bases, such as cytosine paired with guanine and thymine paired with adenine

daughter strands- the newly made

strands after DNA Replication

semi-conservative replication- process of copying DNA, in which the two original strands of the molecule separate and each acts as a template on which a new complementary strand is made

ORIGINAL

DAUGHTER

Lesson 4.3 asexual reproduction- the creation of offspring by only one parent; results in the formation of two clones (examples: budding in hydra, binary fission in bacteria)

binary fission- the form of asexual reproduction and cell division used by all prokaryotes (bacteria); one parent cell divides to produce two identical cells

Lesson 4.4

cell cycle- the series of events involving the growth, replication, and division of a eukaryotic cell

chromosome- Structure in the nucleus of eukaryotic cells that consists of DNA molecules that contain genes; functions in the transmission of hereditary traits

interphase-the phase between cell divisions in which the cell grows, replicates its DNA and is metabolically active

mitosis- division of the nucleus and its chromosomes; consists of 4 stages: 1) Prophase 2) Metaphase 3)Anaphase 4)Telophase

Lesson 4.5 Cytokinesis- division of the cytoplasm and a cell’s organelles; the final step of cell division

sister chromatids - 2 identical copies of a chromosome connected by a centromere

Lesson 4.7 Mutation-a mistake in DNA

Mutagen- An agent, such as radiation or a chemical substance, that causes a genetic mutation

Cancer- disease caused by an uncontrolled division of abnormal cells in a part of the body

risk factor-something that increases the chance of something occurring, for example cancer