Genetics Unit Test Part 1

Grade 11u genetics review

The haploid chromosome number in humans

23

The term phenotype may be defined as

An observable expression of the genotype

Genotype

The genetic makeup of an organism, including all its genes.

Phenotype

The physical traits or characteristics of an organism resulting from its genotype and environment.

A gene exists in two different forms (A and a), which type of gamete can a homozygous recessive individual produce

a

The gene makeup of an organism for a particular trait is its:

genotype.

To determine if an organism with a dominant phenotype is heterozygous, the organism is mated to a:

homozygous recessive for the trait.

During meiosis, genetic variation in the gametes is achieved by

crossing over and random assortment.

If a human has two X chromosomes, it will normally produce:

Females

Colour-blindness is a sex-linked characteristic because the gene is:

carried on a sex chromosome

How many chromosomes does someone with Down Syndrome have

47

If a sperm cell contains 18 chromosomes, a muscle cell from the same organism will contain

18 pairs of chromosomes

If one pair of your 23 chromosomes does not separate during anaphase I of meiosis, it would result in the production of:

four cells with 22 chromosomes and two with 24 chromosomes

Sexual and asexual reproduction are alike in that:

They can both occur in multicellular organisms

in sexually reproducing species, the chromosome number remains stable over time because _____ and _____ always alternate

meiosis, fertilization

Humans possess:

22 pairs of autosomes and 1 pair of sex chromosomes

What is the result when a diploid cell undergoes meiosis:

Four haploid cells

Synapsis occurs during:

prophase I

Homologous chromosomes separate and migrate towards opposite poles

Anaphase I

A tetrad is made up of:

four chromatids from two homologous chromosomes

The major contribution of sex evolution is:

a method to increase genetic variation

The law of independent assortment:

alleles for different traits separate randomly, leading to a 9:3:3:1 ratio. This happens only for genes on different chromosomes

Why is a test cross used:

To determine the genotype of an individual with an unknown phenotype

What is the probability that a male will inherit an X-linked recessive allele from his father:

0%

Karyotypes are useful for

Checking if the chromosome count and structure are normal and determining sex

which process does meiosis division occur

process 4

What process represents a return to a diploid chromosome number

process 1

Which process represents mitosis

process 2 and 3

which cells are considered sex cells

gametes

mit or mei, daughter cells are genetically identical to each other andd parent cell

mitosis

mit or mei, results in two daughter cells

mitosis

cells are haploid

meiosis

mit or mei, introduces genetic variation into a species

meiosis

mit or mei, daughter cells are different from each other and parent cell

meiosis

mit or mei, cells are diploid

mitosis

mit or mei, results in four cells

meiosis

mit or mei, involves two divisions

meiosis