Chapters 9-13

Question 1

stages of the cell cycle and describe

Answer 1

Interphase
G1-Cell growth
S1-DNA replication
G2-Final cell growth
Mitosis -Cell reproduction
Prophase-Nuclear envelope disappears, start to see chromosomes
Metaphase -Sister chromatids line up in the middle
Anaphase -The chromosomes are pulled apart
Telophase-The nuclear envelope begins to reform as chromosomes more closer to polls
Cytokinesis-A cleavage furrow form as the two daughter cells separate

Question 2

types of cell signaling and describe each

Answer 2

Direct
Molecules transferred from cell to cell through contact
Paracrine
Sends molecules/signals to groups or cluster of cells
Endocrine
Sends hormones with the help of the circulatory system to the whole body
Synaptic
Sends neurotransmitters between a gap which will eliote a response in the body

Question 3

similarities/ differences in mitosis and meiosis

Answer 3

Mitosis and meiosis are both ways of continuing cell life. However the difference is in the chromosomes, mitosis makes an exact copy, whereas, meiosis makes a copy then switches it around some. MItosis makes two daughter cells. And Meiosis makes four.

Question 4

what does p53 do

Answer 4

P53 reads the copied DNA and checks for errors. If there is an error, it halts mitosis until it is fixed. IF the DNA damage is irreversible then it orders the cell to kill itself .

Question 5

Define genetic mosaics and tell how they are formed

Answer 5

Genetic mosaics are female heterozygous genes on the X chromosome. They are formed from barr body. For example, a calico cat have multicolored fur. Some cells have the brown fur gene and others have orange fur genes.

Question 6

what happens in nondisjunction of sex chromosomes

Answer 6

XX- normal girl
XY- normal boy
XO- Turner syndrome
YO- more than likely a miscarriage.