100.3

Parthenogenesis is a form of

• sexual reproduction in ciliate protozoa
• sexual reproduction in hermaphrodites
• asexual reproduction in which females produce eggs that develop without fertilization
• asexual reproduction in lower organisms by which progeny arises by fragmentation of a parent organism

The human zygote produced during fertilization

• divides by meiosis
• starts its development in the ovary
• divides by mitosis
• is haploid

Which of the following is true for a species that has a chromosome number of 2n = 16?

• The species is diploid with 32 chromosomes per cell.
• The species has 16 sets of chromosomes per cell.
• Each cell has 8 homologous pairs.
• A gamete from this species has 4 chromosomes.

Which of these statements is false?

• In humans, each of the 22 maternal autosomes has a homologous paternal chromosome.
• In humans, the 23rd pair, the sex chromosomes, determines whether the person is female or male.
• Single, haploid (n) sets of chromosomes in ovum and sperm unite during fertilization, forming a diploid (2n), single-celled zygote.
• At sexual maturity, ovaries and testes produce diploid gametes by meiosis.

In animals, meiosis results in gametes, and fertilization results in

• spores
• gametophytes
• zygotes
• clones

A given organism has 46 chromosomes in its karyotype. We can therefore conclude which of the following?

• It must be a human.
• It must be a primate.
• It must be an animal.
• Its gametes must have 23 chromosomes.

A triploid cell contains three sets of chromosomes. If a cell of a usually diploid species with 42 chromosomes per cell is triploid, this cell would be expected to have which of the following?

• 63 chromosomes in 31 1/2 pairs
• 63 chromosomes in 21 sets of 3
• 63 chromosomes, each with three chromatids
• 21 chromosome pairs and 21 unique chromosomes

Which of the following happens at the conclusion of meiosis I?

• Homologous chromosomes are separated.
• The chromosome number per cell is conserved.
• Sister chromatids are separated.
• Four daughter cells are formed.

Homologous chromosomes synapse and crossing over occurs.

• The statement is true for mitosis only.
• The statement is true for meiosis I only.
• The statement is true for meiosis II only.
• The statement is true for mitosis and meiosis.

Chromatids are separated from each other.

• The statement is true for meiosis I only.
• The statement is true for meiosis II only.
• The statement is true for mitosis and meiosis I.
• The statement is true for mitosis and meiosis II.