Bio 212 exam 3 csulb

What distinguishes living things from nonliving matter?

The ability of organisms to produce more of their own.

What is the significance of cell division in living organisms?

Cell division is essential for the continuity of life.

What are the three main purposes of cell division?

Reproduction, growth and development, and tissue renewal/repair.

What constitutes the cells Genome

All of the DNA in a cell.

What is the difference between prokaryotic and eukaryotic genomes?

Prokaryotic genomes consist of a single DNA molecule, while eukaryotic genomes consist of multiple DNA molecules.

How are DNA molecules organized in a cell?

DNA molecules are packaged into chromosomes.

What is chromatin?

A complex of DNA and protein that condenses during cell division.

What occurs to DNA in preparation for cell division?

DNA is replicated and the chromosomes condense

What are sister chromatids?

Sister chromatids are copies of a duplicated chromosome.

What holds sister chromatids together?

Cohesins attach sister chromatids along their lengths.

What is the centromere?

The centromere is the 'waist' of the chromosome where sister chromatids are closely attached.

Interphase

Cell growth and copying of chromosomes in preparation for cell division.

Mitotic (M) phase

Consists of both mitosis and cytokinesis (cell division).

The entire cell cycle consists of what two parts

interphase and mitotic M phase

What percentage of the cell cycle is made up by interphase?

About 90%

What are the three subphases of interphase?

G1 phase, S phase, and G2 phase

What occurs during the G1 phase of interphase?

The cell grows and prepares for DNA synthesis.

What happens during the S phase of interphase?

Chromosomes are duplicated.

What is the purpose of the G2 phase in interphase?

The cell continues to grow and prepares for mitosis.

What is the role of the mitotic spindle during mitosis?

It controls chromosome movement.

Where do spindle microtubules originate?

They begin in the centrosome.

What happens to the centrosome during interphase?

It replicates, forming two centrosomes.

What structure pulls apart the chromatids during cell division?

The mitotic spindle.

What is the first stage of mitosis after G2?

Prophase

What happens to chromatin fibers during prophase?

They become tightly coiled.

What begins to form during prophase?

Mitotic spindles

What occurs during prometaphase?

The nuclear envelope fragments.

What connects to centromeres during prometaphase?

Kineticores, a protein structure.

What happens to chromosomes during metaphase?

Chromosomes align at the metaphase plate.

What occurs during anaphase regarding sister chromatids?

The cohesin protein complex connecting the sister chromatids is cleaved.

What process occurs during cytokinesis in animal cells?

Cytokinesis occurs by cleavage, forming a cleavage furrow.

What structure forms during cytokinesis in plant cells?

A cell plate forms during cytokinesis.

Cytokinesis

Two daughter nuclei form, and cells are cleaved at the cleavage furrow

What type of cells undergo eukaryotic cell division?

Somatic cells (non-reproductive cells)

What process divides genetic material in eukaryotic cells?

Mitosis

What occurs during cytokinesis?

The cytoplasm is divided following Telophase.

How do prokaryotic cells divide?

Through binary fission

What is the first step in binary fission in bacteria?

The chromosome replicates, beginning at the origin of replication.

What happens to the daughter chromosomes during binary fission?

The two daughter chromosomes actively move apart.

How does the bacterial cell divide during binary fission?

The plasma membrane pinches inward, dividing the cell into two.

What regulates the frequency of cell division?

The cell cycle is highly regulated with specific checkpoints.

What happens at the checkpoints in the cell cycle?

The cell cycle stops until a go-ahead signal is received.

What is the significance of the cell cycle checkpoints?

They ensure proper progression through the cell cycle.

Cyclins and cyclin-dependent kinases (Cdks) do what in the cell cycle?

main proteins that regulate the cell cycle

How does Cdk activity change during the cell cycle?

Cdk activity changes with levels of cyclin.

What complex do cyclin and Cdk form?

They form a complex called MPF (maturation-promoting factor).

What is the role of MPF in the cell cycle?

MPF allows the cell to enter the M-Phase.

What happens to cyclin during the M-Phase?

Cyclin is degraded during the M-Phase.

What are growth factors?

Secreted cellular factors that can be protein or non-protein. that play a crucial role in regulating cell growth, differentiation, survival, and migration.

What functions do growth factors serve?

They stimulate cell growth, proliferation, and healing, among other roles.

What is an external cycle regulator

Growth factors

What is the role of insulin in cellular signaling?

Insulin activates a receptor tyrosine kinase (RTK).

What is platelet-derived growth factor (PDGF)?

PDGF is released by platelets and also activates a receptor tyrosine kinase (RTK).

What type of cells does PDGF signal for proliferation?

PDGF signals proliferation in fibroblasts, which are a type of connective tissue.

How many different growth factors do humans have?

Humans have over 70 different growth factors.

What alterations occur in cancer cell checkpoints?

Cancer cells have altered checkpoints and/or checkpoint regulators.

How do cancer cells produce growth factors?

Cancer cells can make their own growth factors (GFs).

What is a characteristic of cancer cells regarding growth factor signals?

Cancer cells can have active growth factor signals without the presence of the growth factor, such as through receptor tyrosine kinases (RTK).

What happens to checkpoints in cancer cells?

Cancer cells may have inactive or abnormal checkpoints.

What is the process called that converts normal cells into cancer cells?

The process is known as transformation.

What dependencies do transformed cells often lose?

Transformed cells often lose both density and anchorage dependence.

What are the two fates of cancer cells?

Cancer cells can form benign tumors or malignant tumors

What characterizes benign tumors?

Benign tumors form lumps that remain in their original location.

How can localized benign tumors be treated?

Localized benign tumors may be treated with radiation that damages DNA.

What is a key characteristic of malignant tumors?

Malignant tumors invade surrounding tissues and can metastasize to other areas of the body.

What type of treatment is often used for metastatic cancers (malignant)?

Metastatic cancers are often targeted by chemotherapy drugs that focus on the cell cycle.

Are Somatic cells diploid or haploid?

Diploid (2n)

Somatic Cells undergo mitosis and have pairs of...

chromosomes

What is one role of cell division?

Reproduction, which passes on the genome to the new cell.

What is heredity?

The transmission of traits from one generation to the next.

What are genes?

Units of heredity made up of segments of DNA.

What is a characteristic of asexual reproduction?

A single individual passes all of its genes to its offspring, creating a clone or genetically identical individuals.

How does sexual reproduction differ from asexual reproduction?

In sexual reproduction, two parents contribute to offspring with unique combinations of genes.

What is one advantage of sexual reproduction?

It introduces genetic variation among offspring.

Through what structures are genes passed to the next generation in sexual reproduction?

Genes are passed through gametes (sperm and eggs).

What is the primary process by which gametes are produced?

Meiosis

How do daughter cells produced by meiosis differ from those produced by mitosis?

Daughter cells from meiosis are non-identical and have reduced chromosome pairs.

What type of cells are formed at the end of meiosis?

Haploid cells

What happens to homologous pairs during meiosis?

They are split, leading to haploid gametes.

What genetic information do haploid gametes contain?

A mix of maternal and paternal information.

What happens during early prophase I of meiosis?

Each chromosome pairs with its homolog.

What process occurs during meiosis that introduces genetic variation?

Crossing over.

What are the x-shaped sites where crossover occurs called?

Chiasmata.

What happens to homologous pairs of chromosomes at metaphase I of meiosis? in terms independent assortment

They orient randomly.

How do chromosome pairs sort into daughter cells during meiosis?

Each pair sorts independently of the other pairs.

When does random assortment occur during meiosis?

Random assortment occurs during both meiosis I and meiosis II.

What happens during fertilization?

Any sperm can fuse with any ovum (unfertilized egg).

What are gametes?

Reproductive cells, specifically sperm and eggs

What is a zygote?

The cell formed by the fusion of two gametes during fertilization.

What are three ways in which Meiosis can introduce variation to a population?

Crossing over, Independent assortment, and Random fertilization

What is the importance of this variation to natural selection?

It creates a healthier population. higher chance of survival and reproducing in a changing environment. Is good for future generations

Can you think of another source of variation related to meiosis?

Mate choice

Why were peas used as a model for inheritance?

Peas were chosen for their short generation time, large numbers of offspring, and ability to self-pollinate or cross-pollinate.

What is a trait in Mendel's experiments?

A trait is a variant for a character that varies between individuals.

What did Mendel focus on in his pea plant experiments?

Mendel focused on heritable features or characters that varied between individual plants.

What was the outcome of self-breeding true-breeding varieties in Mendel's experiments?

It would always lead to the same trait.

What are the two types of varieties that Mendel used to breed?

Hybridization and True-breeding

Hybridization

The process of mating between two organisms with contrasting traits to produce offspring with a combination of those traits.

True-breeding

organisms that, when consistently mated with others of the same phenotype, produce offspring with identical traits

What did Mendel suggest about how traits are inherited?

Traits do not blend; alternative versions of a gene (alleles) account for inherited characteristics.