Cell bio-Quiz #3

What is a zygote

When an egg and sperm combine

What is growth

An increase in the number of cells and size of cells

What is cell maturation

When cells develop and become specialized for specific functions

One reason why cell division necessary for growth

Increases the number of cells in the body

What must happen before a cell divide’s

DNA must be replicated so each daughter cell receives the correct genetic information

What is cell division

When one cell divides to produce two daughter cells

What is a chromosome

tightly packed DNA that can be moved during cell division

What are sister chromosomes

Two identical copies of a chromosome produced during DNA replication

DNA Replication

Copying DNA so each new cell gets the same genetic information

What are daughter Cells

The two new cells produced when one cell divides

What happens to DNA during cell reproduction?

DNA is replicated, condensed into chromosomes, separated, and distributed to the two daughter cells

What else is distributed during cell division

Cytoplasm and organelles

Purpose of mitosis

Increase the number of cells for growth, development, and tissue repair

When dose mitosis occur

During growth, development, and tissue repair dose not produce sperm or eggs

What is Mitosis

Cell division used to increase the number of body cells

what is Meiosis

Cell division used to produce gametes (sperm and eggs)

Main purpose of mitosis

Growth, development, and tissue repair

Main purpose of meiosis

Production of sperm and eggs

Cell Cycle

Stages a cell goes through as it grows, copies its DNA, and divides

What happens during the G1 phase

Cell Grows and performs its normal functions; DNA is actively directing cell activities

S Phase

The cell replicates its DNA

G2 Phase

DNA has been doubled, and the cell prepares for mitosis

M Phase

Duplicated chromosomes are separated into two daughter cells

Interphase

longest, active stage of the cell cycle

What phases make up interphase

G1+S+G2

When dose DNA replicate

S phase

Which part of the cell cycle takes up most of the time

Interphase (G1, S, and G2)

Is mitosis most of the cell cycle

No. Mitosis is only a small part of the cell cycle

G0 Phase

A cell leaves the active cell cycle and is not preparing to divide

what triggers mitosis

Cycllins and Cdks

What is Cyclin

Protein that helps activate a Cdk and control progression though the cell cycle

What is Cdk (Cyclin-dependent kinase)

Enzyme that becomes active when bound to cyclin and helps trigger cell cycle

What is M-Cdk

Mitotic cyclin-dependent kinase; helps trigger mitosis

What dose MPF do (Maturation-Promoting Factor)

Triggers mitosis it includes cyclin and Cdk activity

What is Kinase

Enzyme that adds a phosphate group to a molecule

What is Phosphorylation

Adds a phosphate group to a molecule

How dose cyclin activates Cdk?

Cyclin binds to Cdk, activating the Cdk so it can trigger events leading to mitosis

Easy way to remember Cdk and Cyclin

Cdk= the key

Cyclin = the battery that activates the key

What happens when cyclin is degraded

Cdk becomes inactive and mitotic activity decreases.

What is Ubiquitin

A chemical tag marks protein like cyclin for degradation

What happens when cyclin concentration increases

M-Cdk activity increases, helping triggger mitosis

What must happen during S phase before mitosis

DNA is replicated

What is DNA Condensation

Tightly packed dna

Why dose DNA condense

Makes it easier to move and separate during mitosis

When dose chromosome condensation begin

End of G2

When is chromosome condensation completed

During prophase

What do microtubules do

Fiber tracks help move chromosomes during mitosis

What must microtubes do during mitosis

Anchored at opposite sides of the cell and attach to chromosomes to move them

What is Kinetochore

Attachment point between microtubules and chromosome

What happens in this region centromere

When sister chromatids are connected and kinetochore forms

what is the 5 stages of mitosis

Prophase, Prometaphase, Metaphase, Anaphase, Telophase

Name 3 things that happen during the interphase

DNA is loose, the nucleus membrane intact goes through G1, S and G2

What happens during the Prophase

Chromosomes become visible as DNA condensation is done nucleus is present

Prometaphase

Chromosomes line up and move to middle of the cell nucleus membrane dissolves

Metaphase

Chromosomes are fully aligned in the middle of the cell; microtubules attach to chromosomes.

Anaphase

Sister chromosomes separate and move toward opposite poles of the cell

Telophase

Chromosomes arrive at two poles, and nucleus membrane starts forming

Cytokinesis

The cytoplasm divides, producing 2 daughter cells

Contractile Ring

Snap and contract the cell in-half made of actin and myosin

Actin and Myosin

Proteins that make up the contractile ring and help divide the cell during cytokinesis

What is a Gene

A section of DNA that codes for a protein

What is a Alles

Copy of one Gene

What is Locus

Gene each less two copies

What is Homologous chromosomes

Pair of chromosomes from mom and dad

Gene expression

Uses gene blueprint to make functional protein

Dominant

Intact able to express a functional protein

Genotype

Exactly what gene is like

Phenotype

Visible character of the individual

Law of Segregation

A pair of alle separate into different gametes and will join together randomly