SAT 2 Cell Division- Mitosis and Meiosis

(D) 4 Explanation: There are 2 replicated chromosomes in this cell but 4 chromatids. The chromatids are the replicated chromosomes strands and are joined at the centromere.

How many chromatids are in this cell? (A) 0 (B) 2 (C) 3 (D) 4 (E) Cannot be determined

(B) 2 Explanation: There are 2 replicated chromosomes in this cell but 4 chromatids. The number of chromosomes is determined by counting the number of centromeres (one per chromosome).

How many chromosomes are in this cell? (A) 0 (B) 2 (C) 3 (D) 4 (E) Cannot be determined

(B) Production of gametes Explanation: Production of gamete (sperm and eggs) occurs by meiosis. This causes the chromosome number to be cut in half. The other choices are characteristic of mitotic cell division. A cleaver furrow forms in animal cells only.

Which of the following does NOT occur by mitosis? (A) Growth (B) Production of gametes (C) Repair (D) Development of an embryo (E) Cleavage furrow forms in animal cells

(B) Cleavage Furrow Explanation: Animal cells develop a cleavage furrow as they undergo cytokinesis. Plant cells form a cell plate down the middle of the cell. Daughter plant cells do not separate from each other. Instead, sticky lamella cements adjacent plant cells together. All plant cells have chromosomes consisting of chromatids and centromeres.

Which of the following is NOT found in plants cells? (A) Cell Plate (B) Cleavage Furrow (C) Middle lamella (D) Centromere (E) Chromatids

(B) Meiotic cell division Explanation: sperm and ovum production is an example of meiotic cell division.

Human makes begin to produce sperm at puberty.

(A) 6 Explanation: Meiosis cuts the chromosome number in half, from diploid 2n to haploid n. This division means that during fertilization, when two gametes fuse, the embryo has the correct chromosome number, 2n. It does not vary with the species.

If a cell has 12 chromosomes at the beginning of Meiosis, how many chromosomes will it have at the end of Meiosis? (A) 6 (B) 12 (C) 24 (D) 48 (E) It varies with the species

(D) D Explanation: During Metaphase I of Meiosis, homologous lairs line up on the Metaphase plate in double file.

Which stage is Metaphase I of Meiosis? (A) A (B) B (C) C (D) D (E) E

(E) E Explanation: During Metaphase II of Meiosis, homologous Pairs line up on the Metaphase plate in single file.

Which stage is Metaphase II of Meiosis ? (A) A (B) B (C) C (D) D (E) E

(A) Mitotic cell division Explanation: Growth and repair are examples of mitosis.

The human liver can be induced to regenerate when liver cells become damaged and need to be replaced.

(B) 12 Explanation: The cells that result from mitotic cell division have the same number of chromosomes as the parent cell. It does not vary with the species.

If a cell has 12 chromosomes at the beginning of mitosis, how many will it have at the end of mitosis (A) 6 (B) 12 (C) 24 (D) 48 (E) It varies with the species.

(A) Interphase Explanation: Chromosomal replication occurs during Interphase. After replication, the chromosomes consist of two sister chromatids that are genetically identical to each other.

Chromosomes replicate during (A) Interphase (B) Prophase (C) Metaphase (D) Anaphase (E) Telophase

(E) Interphase Explanation: Most of the life of the cell is spent in Interphase when the chromosomes are thread like and not visible under a light microscope. The nucleolus is not a real structure but actually a threadlike chromosome organized in a way that forms a sphere like structure. When the cell divides, chromosomes become condensed or supercooled, and the nucleolus disappears.

In which stage in the life of a cell is the nucleolus visible? (A) Prophase (B) Anaphase (C) Telophase (D) Cytokinesis (E) Interphase

(B) B Explanation: During Anaphase II, sister chromatids separate, The chromosome number remains the same.

Which stage is Anaphase II of Meiosis? (A) A (B) B (C) C (D) D (E) E

(A) Mitotic cell division Explanation: a malignant tumor grows larger as cancer cells reproduce by rapid mitotic cell division.

A cancerous tumor grows larger.

(A) Mitotic cell division Explanation: Growth and repair are examples of mitosis

A cut on your skin heals

(A) Mitotic cell division Explanation: The cells of an embryo divide by mitosis.

A fertilized egg grows into a fetus and then a baby during a nine-month gestation period

(A) Mitotic cell division Explanation: the egg may have been formed by Meiosis. Once it is fertilized, however, the growth and development of that zygote occurs by mitosis.

A fertilized ovum undergoes rapid cell division immediately after it is fertilized by a sperm cell.

(C) Spindle fibers are attached to the centriole Explanation: Plants do not have centrioles or centrosomes. Instead, the spindle fibers connect the chromosomes to a microtubule-organizing region. There is no replication of chromosomes between Meiosis I and II because the chromosomes are already replicated double chromatids.

All of the following are true of Meiosis in plants EXCEPT (A) Crossing-over occurs during Prophase. (B) There is no replication of chromosomes between Meiosis I and Meiosis II (C) Spindle fibers are attached to the centriole. (D) Synapsis occurs during Prophase. (E) homologous Pairs of chromosomes line up in the Metaphase plate in Meiosis I.

(C) stem cells Explanation: Stem cells are indefinitely dividing cells that can differentiate into any cell type, cycling are proteins that help to control the rate of cell division. Choice B is nonsense. Internal and external regulators are proteins that help control the progress of a cell dividing.

Cells that retain the ability to divide indefinitely and which can differentiate into any type of cell are called (A) Cyclins (B) Divisible cells (C) stem cells (D) internal regulators (E) External regulators

(B) Prophase Explanation: Most if the life of the cell is spent in Interphase when the chromosomes are threadlike and not visible under a light microscope. When the cell divides. Chromosomes become condensed or supercoiled and become visible. This supercooling occurs during Prophase.

Chromosomes become visible for the first time during (A) Interphase (B) Prophase (C) Metaphase (D) Anaphase (E) telophase