Exam 1: Chromosome and Cellular Reproduction

Question 1

Germ-plasm theory

Answer 1

Only germ-lines cells can divide through meiosis and produce gametes

Question 2

Somatic cells

Answer 2

Cells of the body, non-germ line cells

Question 3

Germ-line cells

Answer 3

The only cells that can divide through meisois and produce gametes

Question 4

Chromosome

Answer 4

Moleucles of DNA that have a number of genes

Question 5

Gene

Answer 5

A DNA sequence that is transcribed

Question 6

Locus

Answer 6

The position of a gene in a chromosome

Question 7

Allele

Answer 7

Different variants of a particular gene

Question 8

Sister chromatids

Answer 8

A conjoined chromosome after DNA replication

Question 9

Homolohous chromosomes

Answer 9

2 chromosomes with the same array of genes, but have different alleles and differnt origins

Question 10

Ploidy

Answer 10

The number of complete sets of unique chromosomes in a cell

Question 11

Chiasmata

Answer 11

The physical interaction of interwining homologous chromosomes, leading to an exchange of DNA

Question 12

Crossing over

Answer 12

The process of exchanging DNA information in a chiasmata between two non-sister chromatids

Question 13

Recombination

Answer 13

The product of crossing over

Question 14

Centromere

Answer 14

Heterochromatic region of a chromosome containing the kinetoichore

Question 15

Cell cycle phases

Answer 15

G1, S, G2, M

Question 16

M phases

Answer 16

Prometaphase, metaphase, anaphase, telophase/cytokinesis

Question 17

Why can’t transcription occur during cell division?

Answer 17

Chromatin is condensed into chromosomes (DNA is not accessible)

Question 18

Metaphase

Answer 18

Alignment of chromsomes at equator

Question 19

Anaphase

Answer 19

Seperation of sister chromatids to opposite poles of the cell

Question 20

Prophse I

Answer 20

2n cells where homologous chromosomes pair together and cross over occurs at the chiasmata

Question 21

Metaphase I

Answer 21

2n cells where homologous chromosomes line up in random order and form the metaphase plate

Question 22

Anaphase I

Answer 22

2n cells where homologous chromosomes seperate and microtubles shorten to pull the chromosomes to their respective cells

Question 23

Telophase I

Answer 23

n cells arise from chromosomes arriviing at poles and cytokinesis occuring

Question 24

Prophase II

Answer 24

Chromosomes condense again without recombination

Question 25

Metaphase II

Answer 25

Chromosomes line up on metaphase plate

Question 26

Anaphase II

Answer 26

Sister chromatids connected at centromere seperate and MTs shroten and pull chromatids towards opposite poles

Question 27

Telophase II

Answer 27

Chromosomes arrive at poles and cytokinesis occurs and results in 4 n cells

Question 28

What are the reasons for mitosis to occur?

Answer 28

healing, growing, and developement

Question 29

What are the reasons for meisosis to occur?

Answer 29

Gametogenesis

Question 30

Possible combination of gametes =

Answer 30

2 to the n where n is the number of pairs in that species

Question 31

Cohesin

Answer 31

Holds sisters chromatids together

Question 32

Shugoshin

Answer 32

Protects cohesin from getting cleaved by separase at centromere during meisosis meisois one

Question 33

Spermatogenesis

Answer 33

Spermatogonia can undergo repeated rounds of mitosis and may enter prophase I of meiosis and become primary spermatocytes. Then, after completing meiosis I, the primary spermatocytes produce 2 secondary spermatozoa that are n. These both undergo meiosis II and produce 2 spermatids that are n and can mature into sperm after several days

Question 34

Oogenesis

Answer 34

Oogonium enter prophase I and become primary oocytes. Then, this primary oocyte undergoes meiosis I and produces one large secondary oocyte that is n and the 1st polar body that goes away. This secondary oocyte compeltes meiosis II and produces an ovum that is n and a 2nd polar body that also goes away. In some animals, meiosis II takes palce afte rthe sperm has penetrated the secondary oocyte.

Question 35

When does oogeneis start in females?

Answer 35

Before birth and then meiosis is pasued until puberty