Chapter 29, Problem 1MC

Summary Introduction

To determine:

Match between the key terms and there description:

Key: (a) alleles (b) autosomes (c) dominant allele (d) genotype (e) heterozygote (f) homozygote (g) phenotype (h) recessive allele (h) recessive allele (i) sex chromosomes

(1) genetic makeup (2) how genetic makeup is expressed (3) chromosomes that dictate most body characteristics (4) alternate forms of the same gene (5) an individual bearing two alleles that are the same for a particular trait (6) an allele that is expressed whether in single or double dose (7) an individual bearing two alleles that differ for a particular trait (8) an allele that must be present in double dose to be expressed

Answer to Problem 1MC

Solution:

Key	Description
(a) Alleles	(4) Alternative forms of the same gene
(b) Autosomes	(3) Chromosomes that dictate most body characteristics
(c) Dominant allele	(6) An allele that is expressed whether in single or double dose
(d) Genotype	(1) Genetic makeup
(e) Heterozygote	(7) An individual bearing two alleles that differ for a particular trait
(f) Homozygote	(5) An individual bearing two alleles that are same for a particular trait
(g) Phenotype	(2) How genetic makeup is expressed
(h) Recessive allele	(8) An allele that must be present in double dose to be expressed.
(i) Sex chromosomes	Determine whether an individual will be male or female

Explanation of Solution

(a) Alleles are located on the chromosome and refer to each of the two forms of the gene, which occurs by mutation.

(b) Autosomes refer to any chromosome that gives a body characteristic. It is not a sex chromosome.

(c) The dominant allele is a pair of chromosomes that occupy the same site of the chromosomes and it controls the character. It will be expressed whether it is in single or double dose.

(d) Genotype refers to the genetic makeup of the organism. It also refers to the group of organisms with reference to a trait.

(e) Heterozygote is an individual that consists of two different alleles of one gene or genes. It also helps in giving rise to an offspring.

(f) Homozygote refers to an individual that consists of two similar gene or genes. It carries the same form of the gene for a particular trait.

(g) Phenotype gives the body characteristics. It gives the observable features or traits such as morphology, behavior, and development of an organism.

(h) A recessive allele is an alternative form of a gene that is present in a chromosome and controls the same character. It will be expressed only in the double dose.

(i) Sex chromosomes are a pair of chromosomes that reveals whether the individual is male or female. In mammals, these are designed as X and Y chromosomes.