Biology 2020 Learning Goals Unit 4 - Heredity and Continuity of Life

These flashcards cover key concepts and definitions from the Biology 2020 Learning Goals for Unit 4 on heredity and the continuity of life.

What is the structure of DNA?

DNA is a double-stranded molecule composed of nucleotides bound to proteins in chromosomes.

What is the role of helicase in DNA replication?

Helicase unwinds the double helix and separates the strands during DNA replication.

Define the term 'gene'.

A gene is a region of DNA made up of nucleotides; it is the molecular unit of heredity.

What is the difference between spermatogenesis and oogenesis?

Spermatogenesis produces sperm in males, while oogenesis produces eggs in females, with differences in haploid and diploid stages.

Explain what mutations are and how they can occur.

Mutations are changes in genes or chromosomes that can occur because of DNA replication errors, cell division mistakes, or damage from mutagens.

What is aneuploidy and how does non-disjunction lead to it?

Aneuploidy is an abnormal number of chromosomes resulting from non-disjunction, where chromosomes fail to separate properly.

Describe the purpose of the polymerase chain reaction (PCR).

PCR is used to amplify specific DNA sequences, making many copies of a particular DNA segment.

What are the three main types of phenotypic selection?

The three types are stabilizing, directional, and disruptive selection.

How does speciation occur?

Speciation occurs due to the accumulation of microevolutionary changes and can involve various mechanisms of isolation.

Define polygenic inheritance.

Polygenic inheritance is when one characteristic is controlled by two or more genes.