CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In a monohybrid cross Aa × Aa (practice 12), what fraction is expected to be homozygous recessive?
A. 1/2
B. 1
C. 3/4
D. 1/4
Correct Answer: D
Aa × Aa gives 1 AA : 2 Aa : 1 aa.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
For a heterozygous individual Aa (practice 11), what is the probability a gamete carries allele a?
A. 1
B. 3/4
C. 1/2
D. 1/4
Correct Answer: C
Alleles segregate equally.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In a test cross Aa × aa (practice 10), what proportion is expected to show the recessive phenotype?
A. 3/4
B. 0
C. 1/4
D. 1/2
Correct Answer: D
Half the offspring are expected to be aa.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In a monohybrid cross Aa × Aa (practice 9), what fraction is expected to be homozygous recessive?
A. 1
B. 3/4
C. 1/2
D. 1/4
Correct Answer: D
Aa × Aa gives 1 AA : 2 Aa : 1 aa.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
For a heterozygous individual Aa (practice 8), what is the probability a gamete carries allele a?
A. 3/4
B. 1/2
C. 1
D. 1/4
Correct Answer: B
Alleles segregate equally.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In a test cross Aa × aa (practice 7), what proportion is expected to show the recessive phenotype?
A. 1/2
B. 3/4
C. 0
D. 1/4
Correct Answer: A
Half the offspring are expected to be aa.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In a monohybrid cross Aa × Aa (practice 6), what fraction is expected to be homozygous recessive?
A. 1/4
B. 1
C. 3/4
D. 1/2
Correct Answer: A
Aa × Aa gives 1 AA : 2 Aa : 1 aa.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
For a heterozygous individual Aa (practice 5), what is the probability a gamete carries allele a?
A. 3/4
B. 1/4
C. 1
D. 1/2
Correct Answer: D
Alleles segregate equally.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In a test cross Aa × aa (practice 4), what proportion is expected to show the recessive phenotype?
A. 0
B. 3/4
C. 1/2
D. 1/4
Correct Answer: C
Half the offspring are expected to be aa.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In a monohybrid cross Aa × Aa (practice 3), what fraction is expected to be homozygous recessive?
A. 3/4
B. 1
C. 1/2
D. 1/4
Correct Answer: D
Aa × Aa gives 1 AA : 2 Aa : 1 aa.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
For a heterozygous individual Aa (practice 2), what is the probability a gamete carries allele a?
A. 3/4
B. 1
C. 1/2
D. 1/4
Correct Answer: C
Alleles segregate equally.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In a test cross Aa × aa (practice 1), what proportion is expected to show the recessive phenotype?
A. 0
B. 1/2
C. 3/4
D. 1/4
Correct Answer: B
Half the offspring are expected to be aa.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
The enzyme that joins Okazaki fragments is:
A. DNA ligase
B. RNA polymerase
C. Amylase
D. Helicase
Correct Answer: A
Ligase seals fragments.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
The enzyme that unwinds DNA during replication is:
A. Ligase
B. Pepsin
C. Amylase
D. Helicase
Correct Answer: D
Helicase separates the strands.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
Semiconservative replication means each daughter DNA has:
A. one old strand and one new strand
B. RNA only
C. two new strands
D. two old strands
Correct Answer: A
Each duplex contains one parental strand.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
Chromosomes align at the equator during:
A. Anaphase
B. Telophase
C. Metaphase
D. Prophase
Correct Answer: C
Alignment occurs in metaphase.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
Sister chromatids separate in mitosis during:
A. Anaphase
B. Prophase
C. Metaphase
D. Telophase
Correct Answer: A
Chromatids move apart in anaphase.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
Human somatic cells normally contain:
A. 24 pairs
B. 22 pairs
C. 46 pairs
D. 23 chromosome pairs
Correct Answer: D
Somatic cells contain 23 pairs.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
A human gamete normally contains:
A. 22 chromosomes
B. 46 chromosomes
C. 44 chromosomes
D. 23 chromosomes
Correct Answer: D
Human gametes are haploid.
CSS - PMS - CCE - PCS - Everyday Science
Cell BiologyDNA and Genetics
In DNA, guanine pairs with:
A. Cytosine
B. Uracil
C. Thymine
D. Adenine
Correct Answer: A
G pairs with C.