Part 2

In an organism with a haploid number of 9, a skin cell has ______ chromosomes, a developing sperm cell at prophase II of meiosis has ______ chromosomes, and a newly formed zygote has ______ chromosomes.

18; 9; 18

In a diploid species, an individual can carry a maximum of ______ different allele(s) of a given gene.

2

In mice, 2n = 40. A mouse cell that is the product of meiosis I contains:

20 replicated chromosomes

In mice, 2n = 40. Each mouse cell that is the product of meiosis II will contain

20 unreplicated chromosomes

How many chromosomes are in a human sperm cell?

23

How many pairs of chromosomes are there in the human genome?

23

A human sperm cell contains ______ chromosomes and ______ copies of the HBB gene (the gene that encodes the beta-globin protein).

23; 1

In humans, 2n = 46. A human gamete contains ______ chromosomes, and a human zygote contains ______ chromosomes.

23; 46

A bivalent (also called a tetrad) consists ______ chromosomes and a total of ______ chromatids.

2; 4

When DNA polymerase corrects an incorrect base pair by proofreading, it removes and replaces the nucleotide located at the

3' end of the daughter DNA strand

When a human somatic cell divides by mitosis, how many chromosomes are in each of the daughter cells?

46

In humans, the diploid chromosome number is 46 (2n = 46). A human germ cell that has just replicated its DNA in preparation for meiosis contains ______ chromosomes and ______ copies of the HBB gene (the gene that encodes the beta-globin protein).

46; 4

Horses have a diploid number of 64 chromosomes (2n = 64). In a horse cell that is in metaphase I, how many chromosomes, chromatids, and bivalents (tetrads) would be present?

64 chromosomes, 128 chromatids, and 32 bivalents

Approximately how long after fertilization does implantation occur, in humans?

8 days

The mouse diploid genome (2n) contains 40 chromosomes. A mouse cell at the end of prophase I contains:

80 chromatids, 40 chromosomes, and 20 tetrads

How many base pairs are represented in the DNA sequence below? 5'-CCGATCAAG-3' 3'-GGCTAGTTC-5'

9 base pairs

The inner cell mass of the blastula develops into:

An embryo with three cell layers: ectoderm, endoderm, and mesoderm

Homologous chromosomes separate from each other during

Anaphase I of meiosis

During meiosis, the sister chromatids separate during

Anaphase II

How does binary fission differ from mitosis?

Binary fission does not require microtubules.

After replication, sister chromatids are held together by a protein called

Cohesin

The protein that holds together sister chromatids is called

Cohesin

What is the genome of an organism made of?

DNA

HbA and HbS are two alleles of the human β-globin gene. If a person carries both the HbA and HbS alleles of the β-globin gene, when could the chromosomes pictured below be observed?

During meiosis I

What are the three germ layers found in a vertebrate gastrula?

Ectoderm Endoderm Mesoderm

What are the germ layers found in an animal with diploblastic development?

Endoderm Ectoderm

What are the germ layers found in an animal with triploblastic development?

Endoderm Ectoderm Mesoderm

T/F Organisms that are large and complex always have larger genomes than small, simple organisms.

False

What process results in formation of a zygote?

Fertilization

Meiosis results in the production of

Four haploid daughter cells

During cleavage, the cell cycle is modified so that cell division occurs rapidly and without cell growth. Which phase(s) of the cell cycle is likely to be eliminated or extremely shortened during these cell divisions?

G1

Which of the following types of cells are haploid?

Gamete

The products of meiosis are called

Gametes

Which of these terms best describe the entire set of genetic information found within a cell?

Genome

The cell that enters meiosis is called a

Germ Cell

A cell that has completed meiosis I but has not yet entered meiosis II contains ________ as a germ cell in G2 (right before meiosis).

Half as much DNA Half as many chromosomes

At the end of meiosis I, the daughter cells that are produced are ______ and contain ______ chromosomes.

Haploid; Replicated

All animals with bilateral symmetry

Have triploblastic development

A frameshift mutation could result from:

Insertion of two bases in the coding sequence. Insertion of a single base in the coding sequence. Deletion of a single base in the coding sequence.

The separation of sister chromatids in a eukaryotic cell:

Is called mitosis.

External fertilization:

Is found in some fish and amphibians. Involves releasing gametes directly into a wet environment.

A point mutation may have no effect on an organism if:

It occurs in a non-coding region of DNA. It results in a different codon for the same amino acid.

During cell division, spindle fibers attach to

Kinetochore proteins

In eukaryotes, the process that is used to produce gametes is called _________.

Meiosis

Homologous chromosomes separate from each other during

Meiosis I only.

Point mutations that cause amino acid replacements are called _____.

Missense mutations

DNA replication occurs before

Mitosis and Meiosis I

The compact cluster of cells that results from cleavage is called a

Morula

Which of the following cellular functions depend on microtubules?

Movement of chromosomes during cell division Intracellular transport Cell movement using cilia and flagella

Replication of a eukaryotic chromosome begins at

Multiple origins of replication

What happens during crossing over?

Non-sister chromatids from the same homologous pair exchange DNA.

How many copies of the beta-globin gene are present in a mouse cell that is the product of meiosis II?

One

A somatic cell of a human male contains:

One Y chromosome and one X chromosome.

A newly formed gamete (a cell that has completed both meiotic divisions) contains ________ as a germ cell in G2 (right before meiosis).

One quarter of the amount of DNA Half as many chromosomes

An animal that has internal fertilization but completes development in an egg laid outside the mother's body is

Oviparous

Homologous chromosomes can be defined as:

Pairs of chromosomes that have the same size and appearance.

Crossing over (the exchange of genetic material between chromatids on homologous chromosomes) occurs during

Prophase I.

Which of the following structures are derived from the embryonic mesoderm?

Red blood cells Kidney tubule cells Muscle

A point mutation may be introduced into a gene during the process of:

Replication

Which of the following events occur during interphase of the eukaryotic cell cycle?

Replication of the genome Cell growth

During the eukaryotic cell cycle, DNA is replicated during:

S phase

Which of the following events occur during M phase of the eukaryotic cell cycle?

Separation of chromosomes Division of the cytoplasm

A point mutation that does not result in a change in the amino acid sequence of a protein is called a _____.

Silent mutation

Which of the following cell types are gametes?

Sperm Egg

How does the nucleus of a cell in G2 differ from the nucleus of the same cell in G1?

The G2 nucleus has twice the amount of DNA as the G1 nucleus.

In animals that are protostomes, the blastopore develops into

The Mouth

Select all statements that are correct about the two chromosomes that are circled in this diagram.

These two chromosomes are called homologous chromosomes. These two chromosomes contain the same genes in the same order.

Which of the following statements about sister chromatids are correct?

They are attached to each other at a region called the centromere. They are formed when a chromosome undergoes replication. They have identical DNA sequences.

Chronic myelogenous leukemia (CML) is caused when a segment of chromosome 9 and a segment of chromosome 22 both break off and switch places. How is this mutation classified?

Translocation

How many copies of the beta-globin gene are present in a mouse cell that is the product of meiosis I?

Two

Which structure supports fetal development in mammals?

Uterus

Nearly all mammals, including humans, are

Viviparous

The layer of glycoproteins that surrounds a human egg cell is called the

Zona Pellucida

Which of the following sequences lists the stages of animal development in the correct order, from first to last?

zygote, morula, blastocyst, gastrula, fetus