Honors Bio Unit 4 Exam

Why do cells reproduce?

GARRR

What does GARRR stand for?

Growth, Asexual Reprodution, Repair/Replace

How do cell divide?

Through Mitosis and Cytokinesis

What does mitosis do?

It divides a cell’s nucleus into two genetically identical nuclei (so both have the same exact DNA)

What does cytokinesis do?

Divides the cytoplasm into two separate cells and completes the cell cycle

What is chromatin?

1. combination of DNA & protein fibers 2. long, thin fibers of DNA

How is chromatin packed?

Loosely packed

What are chromosomes?

Chromatin that is condensed

What does condensed mean?

Tightly packed DNA

When stage are chromosomes found in?

Only found during cell division

What are sister chromatids?

A copy that DNA makes of its self for the new cell before a cell can reproduce

What happens for sister chromatids?

Chromosomes (DNA) duplicate, and the identical copies are sister chromatids

What does Asexual Reproduction do?

Use mitosis to create more of itself

What does the genetic information look like for the offspring in Asexual Reproduction?

Genetically identical to the parent

What organisms do Asexual Reproduction?

Only some organisms reproduce asexually, such as bacteria and yeast

How do most multicellular organisms create offspring?

Sexual Reproduction

What organisms do sexual reproduction?

Plants, animals and fungi do meiosis to create gametes

What are gametes?

Sperm and egg cells

What is the genetic information for the offspring like in sexual reproduciton?

The offspring are not identical as the genetic material from both parents combine

What are the four nucleotides that make up a DNA chain?

A, T, C, G

What is a gene?

A long stretch of DNA that codes for a protein or a group of proteins

What is a chromosome (simpler answer)

An entire chain fo DNA along with a group of stabilizing proteins

What is the cell cycle?

The sequence of events in cell reproduction

When does the cell cycle start?

When a new cell is created from existing cells

When does the cell cycle end?

When the new cell reproduces

What is Interphase?

A long period of growth and DNA replication for the cell

What happens to the cell during interphase?

The cells grow to normal size

What happens to the chromosomes during interphase?

Chromosomes duplicate for cell reproduction

What is the Miotic (M) phase?

It includes mitosis and cytokenesis

What is mitosis?

Duplicated chromosomes divide into two identical nuclei

What is cytokinesis?

The cytoplasm is divided into two cells

How many steps does the M phase have?

5 steps

What happens during Prophase?

Chromosomes condense and become visible as the nucleus breaks down

What happens during Metaphase?

Chromosomes line up down the middle of the cell

What happens during Anaphase?

Sister chromatids are pulled to opposite ends of the cell

What happens during Telophase?

Nuclear envelopes reform, chromosomes unfold into chromatin so cytokinesis can begin

What is a cell plate?

A structure that forms when the cytoplasm of the plant cell divides

What is differentiation?

The process by which cells become specialized

What are stem cells?

The unspecialized cells from which differentiated cells develop from

What are Totipotent cells?

Cells that are able to do everything/develop into any type of cell in the body

What are Pluripotent cells?

Cells that can develop into any of the body’s cell types, but generally cannot form the tissues surrounding the embryo

What are Multipotent cells?

Adult cells

What are Multipotent cells limited in doing?

The types of differentiated cells they can form are usually limited to replacing cells in the tissues where they are found

What do Adult cells do?

Produce new cells needed for tissues with limited life span

What are embryonic cells compared to adult cells?

Embryonic cells are more versatile than

What is cancer?

Uncontrolled cell division

What does cancer produce?

It produces a mass of cells called a tumor

What can tumors be?

Benign or malignant

What is benign?

Unusual mass of normal cells

What is malignant?

Abnormal mass of cancer cells

What is metastasis?

The spread of cancer beyond the original site.

What causes cancer?

Mutations in DNA that affect the cell cycle

What causes mutations?

Exposure to mutagens or carcinogens

How does inheriting cancer work?

Most mutations happen in the rogan where cancer begins or in gametes that can be passed down onto offspring

What does inherited mutations do to the risk of cancer?

Increases the risk of cancer, but they do not necessarily develop cancer

What is karyotype?

A display of 46 chromosomes in humans that occur in paris

What are homologous chromosomes?

A part of chromosomes that carry the same sequence of genes but they are not identical

All the cells in you rbody are…?

Diploid, containing 23 pairs of homologous chromosomes

What cells aren’t diploid?

Haploid cells, that contain half of the number of chromosomes and are not in pairs.

What cells are haploid?

Sex cells/ gametes

What is fertilization?

When a haploid sperm cell fuses with a haploid egg cell

What is a zygote?

A fertilized egg that has a diploid number of chromosomes

How are sex cells haploid?

Meisosis

What is meiosis?

Cell division process that produces 4 cells (only sex cells)

How many divisions does meiosis have?

Two divisions to get the haploid number of chromosomes in sex cells