Bio

types of signaling/ contacts

paracrine signaling (local signaling between nearby cells), endocrine signaling (long-distance signaling via hormones in the bloodstream), autocrine signaling (a cell signaling itself), and juxtacrine signaling (direct cell-to-cell contact signaling

Positive feedback

a process where a change in a system causes a greater change in the same direction, amplifying the signal and moving the system away from its starting point

Negative feedback

process that helps maintain homeostasis, or a constant internal state, in the body.

• chromosomes

thread-like structures located inside the nucleus of animal and plant cells

• chromatids

one of the two identical halves of a chromosome that are created when a chromosome duplicates in preparation for cell division:

• # of chromosomes after certain stages/steps

After the S phase of the cell cycle (DNA replication), the number of chromosomes remains the same, but each chromosome consists of two identical sister chromatids, effectively doubling the number of chromatids present within the cell; during mitosis, the number of chromosomes in each daughter cell at the end (after telophase and cytokinesis) is the same as the parent cell, with each daughter cell receiving a full set of chromosomes

• effects of mutagens

agents that cause mutations in DNA, can have a wide range of effects including causing genetic diseases, contributing to cancer development, impacting cell function, and potentially leading to developmental abnormalities

• protein kinase/

an enzyme that adds phosphates to other proteins, which can activate or deactivate them

• secondary messenger (CAMP)

small molecule transiently produced intracellularly that regulates the activity of a protein kinase (PKA) downstream of the agonist (first messenge

• effects of (disruptions to) signaling transduction pathways

cellular malfunctions, often resulting in disease states, including abnormal cell growth, differentiation, metabolism, and death

• homeostasis

the state of balance that living organisms maintain in their internal physical and chemical conditions

• order of cell cycle phases

G1 phase (Gap 1), S phase (Synthesis), G2 phase (Gap 2), and M phase (Mitosis),

• what happens in each stage

the G1 phase involves cell growth and preparation for division, the S phase is where DNA replication occurs, the G2 phase is further preparation for division, and the M phase is where the cell actually divides through mitosis and cytokinesis, resulting in two daughter cells

• density dependent inhibition

is a process that regulates cell growth by stopping cells from dividing when they reach a certain density

• homologous chromosomes

Chromosomes are structures found in the center (nucleus) of cells that carry long pieces of DNA

• somatic cells

the smallest unit that can live on its own and that makes up all living organisms and the tissues of the body.

• centromere (in relation to # of sister chromatids)

sister chromatid contains half of the original chromosome's genetic material. Two sister chromatids will duplicate and separate into four identical chromosomes.

What is homeostasis?

The state of balance that living organisms maintain in their internal physical and chemical conditions.