Chapter 2 - Reproduction

Question 1

Metathatarian

Kangaroo, koalas

Answer 1

Fetus undergoes some development in the uterus, but then climbs out of the birth canal into mom’s marsupium/pouch.

Question 2

If a cell is DIPLOID what does it mean?

Answer 2

It contains two copies of each chromosome.

Question 3

If a cell is HAPLOID what does it mean?

Answer 3

They contain only one copy of each chromosome. (For example, germ cells)

Question 4

4 stages of the cell cycle:

For actively dividing cells

Answer 4

G1

S

G2

M

Question 5

In the cell cycle, what is interphase?

Answer 5

The first 3 stages of the cell cycle (G1, S, G2) are called “interphase”

The longest part of the cell cycle (about 90%of it)

Question 6

In what phase of the cell cycle are non-dividing cells in?

Answer 6

An offshoot of G1 called G0

No preparation for division

Question 7

Prototherians

Platypus, echidna

Answer 7

Type of mammal.

Embryos are in hard shells and hatched like reptiles. (Oviparity)

Question 8

Chromatin
How does it relate to interphase?
How does that differ from M phase?

(Basics are in ch1)

Answer 8

What chromosomes are made of.

In interphase, chromosomes are not visible with light microscopy because they are in a less condensed form, KNOWN AS CHROMATIN.

This makes it available to the enzyme RNA polymerase so that genes can be transcribed.

In M phase, DNA needs to be condensed in tightly wound chromosomes to avoid losing any enteral material during division.

Question 9

Cytokinesis

Answer 9

The splitting of the cytoplasm and organelles into two daughter cells

Question 10

4 stages if mitosis

PMAT

Answer 10

Prophase
Metaphase
Anaphase
Telophase

Question 11

What happens during G1 stage of the cell cycle?

Answer 11

Cells create organelles for energy and protein production (ribosomes, mitochondria, ER)

Restriction point: cell must have the proper complement of DNA to pass restriction point and enter S stage

Question 12

What happens in S stage of cell cycle?

Answer 12

Cell replicated the genetic material so that each daughter cell will have identical copies.

Each chromosome undergoes replication so that there are two identical CHROMATIDS each bound together by a centromere.

(In this stage, ploidy doesn’t change: 46 chromosomes but 92 chromatids are present.)

CELLS IN G1 have half as much DNA as cells in G2!

Question 13

Ploidy

Answer 13

The number of sets of chromosomes.