7th Grade Life Science: Chapter 3 Study Guide

Comprehensive vocabulary flashcards covering DNA and RNA structures, protein synthesis, cell division, and reproduction for 7th Grade Life Science Chapter 3.

Nucleic Acids

A category of biological molecules that includes DNA and RNA, composed of nucleotide subunits.

Nucleotide

The basic building block of nucleic acids, consisting of three components: a phosphate, a sugar, and a nitrogen base.

DNA (Deoxyribonucleic Acid)

The genetic material inside cells that replicates before division and contains the nucleotide base pairs adenine (A) with thymine (T), and guanine (G) with cytosine (C).

RNA (Ribonucleic Acid)

A single-stranded nucleic acid involved in protein synthesis that utilizes the base pairs adenine (A) with uracil (U), and cytosine (C) with guanine (G).

DNA Base Pairs

The complementary base pairs found in DNA: adenine (A) pairs with thymine (T), and guanine (G) pairs with cytosine (C).

RNA Base Pairs

The complementary base pairs found in RNA: adenine (A) pairs with uracil (U), and cytosine (C) pairs with guanine (G).

mRNA (Messenger RNA)

The type of RNA that carries a transcribed copy of the genetic code from DNA to the ribosome.

tRNA (Transfer RNA)

The type of RNA responsible for transferring amino acids to the ribosome during translation.

rRNA (Ribosomal RNA)

The type of RNA that forms the structural and functional component of ribosomes.

Transcription

The process of making an mRNA copy of a gene from a DNA template.

Translation

The process in which the genetic code carried by mRNA is decoded at the ribosome to make a protein.

Protein Synthesis

The two-step cellular process comprising transcription and translation that builds proteins based on the genetic code.

Codon

A three-nucleotide sequence on an mRNA molecule that specifies a particular amino acid during translation.

Amino Acids

The individual building blocks linked together to form proteins, whose sequence is determined by the base order of the gene.

Gene

A specific segment of DNA whose nucleotide sequence determines the order of amino acids in a protein.

Protein

A macromolecule assembled from chains of amino acids decoded from mRNA during translation.

Ribosomes

The cellular structures made of rRNA and protein where mRNA is translated into amino acid chains.

Nucleus

The cell organelle that houses DNA and serves as the site where transcription takes place.

DNA Replication

The process by which a cell creates an identical copy of its DNA before undergoing cell division (mitosis).

Cell Cycle

The complete sequence of growth and division phases in a cell, consisting of Interphase, Mitosis, and Cytokinesis.

Interphase

The stage of the cell cycle during which the cell grows, performs normal functions, and replicates its DNA before dividing.

Mitosis

The phase of the cell cycle in which the duplicated nucleus divides to help cells reproduce and grow, producing two daughter cells with an identical chromosome count (e.g., $62$ chromosomes in a donkey cell).

Cytokinesis

The final stage of the cell cycle following mitosis where the cytoplasm divides to form separate daughter cells.

Meiosis

The specialized form of cell division that reduces the chromosome number by half to produce gametes (e.g., yielding $31$ chromosomes from a $62$-chromosome donkey cell, or $22$ chromosomes in a rabbit egg cell).

Asexual Reproduction

A reproductive process involving a single parent that results in offspring that are genetically identical to the parent.

Sexual Reproduction

A reproductive process involving gametes that produces offspring that are genetically different from both parents.