Biology Today and Tomorrow with Physiology

Cecie Starr, Christine Evers, Lisa Starr

ISBN #9780357127544

6th Edition

435 Questions

25,739 Students Helped

Homework Questions

Summary

Learning Objectives

Key Concepts

Example Problems

Explanations

Common Mistakes

Summary

This textbook section covers fundamental and advanced concepts behind patterns of inheritance, starting from Mendelian principles demonstrated through monohybrid and dihybrid crosses to complex interactions like incomplete dominance, codominance, epistasis, and pleiotropy. It also addresses environmental effects on gene expression and the importance of pedigree analysis in human genetic studies. Moreover, the chapter explains how nondisjunction leads to chromosomal abnormalities such as trisomy and monosomy, and highlights the practical applications of genetic screening and prenatal diagnostics in mitigating genetic disorders.

Learning Objectives

Key Concepts

CONCEPT

DEFINITION

No concepts available

No definitions available for this book.

Example Problems

Example 1

A heterozygous individual has ________ a. the same allele on both homologous chromosomes b. two different alleles of a gene c. a haploid condition, in genetic terms

Example 2

An organism's observable traits constitute its __________ a. phenotype b. variation c. genotype d. pedigree

Example 3

The offspring of the cross $A A \times a a$ are ___________ a. all $A A$ b. all $a a$ c. all $A a$ d. half are $A A$ and half are a $a$

Example 4

The probability of a crossover occurring between two genes on the same chromosome _________ a. is unrelated to the distance between them b. decreases with the distance between them c. increases with the distance between them

Example 5

If one parent is heterozygous for a dominant allele on an autosome and the other parent does not carry the allele, any child of theirs has a ___________ chance of being heterozygous. a. 25 percent b. 50 percent c. 75 percent