D2.1 HL only Flashcards
zygote
a cell that forms when a sperm and egg fuse during fertilization
embryo
the early stage of development for a multicellular organism, such as a human, animal, or plant
Ectoderm
the outermost layer of cells in an embryo, and is the source of many tissues and organs
Mesoderm
the middle layer of cells in an embryo that develops into many tissues and organs
Endoderm
the innermost layer of cells in a developing embryo
differentiate
the process by which immature cells become mature cells with specific functions
Meristem
a plant tissue made up of undifferentiated cells that can divide and develop into other cell types
stem cells
cells that can divide and differentiate into many different types of cells in the body
Apical meristem
a region of actively dividing cells at the tips of plant roots and shoots that is responsible for primary growth
Lateral meristem
a type of plant tissue that allows plants to grow in width, or laterally
cell cycle
the series of events that take place in a cell before it divides
Interphase
the stage of the cell cycle when a cell grows, replicates its DNA, and prepares for cell division
G1 phase
the first stage of the cell cycle, where a cell prepares to divide by growing and making proteins
S phase
a stage of the cell cycle when DNA is copied
G2 phase
the period in the cell cycle when a cell grows, synthesizes proteins, and prepares for mitosis
M phase
the stage of the cell cycle when a cell divides into two new cells
G0 phase
a resting state of a cell where it is not dividing or preparing to divide
Gene expression
the process by which the information encoded in a gene is turned into a function
protein synthesis
the process by which cells create proteins, which are essential for the functioning of living organisms
Checkpoints
a control point in the cell cycle that assesses conditions before allowing the cell to progress
cyclin
proteins that regulate the cell cycle
cyclin-dependent protein kinases (CDKs)
enzymes that regulate cell division and transcription
G1 checkpoint
a critical point in the cell cycle that determines whether a cell can proceed to DNA replication and cell division
G2 checkpoint
a control point in the cell cycle that ensures DNA is replicated and undamaged before a cell divides
M checkpoint
a cell cycle mechanism that ensures chromosomes are properly attached to the spindle apparatus before cell division
DNA polymerase
an enzyme that copies DNA during cell division
Carcinogens
a substance, organism, or agent that can cause cancer
Cancer
a disease that occurs when cells grow and divide uncontrollably, which can lead to the formation of tumors that spread to other parts of the body
tumor
an abnormal growth of tissue that forms when cells grow and divide too much or don’t die when they should
Proto-oncogenes
genes that normally help cells grow and divide, but can become oncogenes that cause cancer if they mutate
oncogenes
mutated genes that can cause cancer by causing cells to grow and divide uncontrollably
apoptosis
a biological process that involves the destruction of cells that are no longer functional
Tumor suppressor genes (TSGs)
genes that regulate cell growth and division, and can prevent the development of cancer
Benign tumor
a non-cancerous growth that doesn’t spread to other parts of the body
chemotherapy
a cancer treatment that uses drugs to kill or stop the growth of cancer cells
radiotherapy
The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors
Malignant tumor
cells that grow uncontrollably and spread locally and/or to distant sites
primary tumor
A term used to describe the original, or first, tumor in the body
secondary tumor
A term used to describe cancer that has spread (metastasized) from the place where it first started to another part of the body
metastasis
The spread of cancer cells from the place where they first formed to another part of the body
oncologists
A doctor who has special training in diagnosing and treating cancer in adults using chemotherapy, hormonal therapy, biological therapy, and targeted therapy
Mitotic index
the ratio of the number of cells undergoing mitosis (cell division) to the number of cells not undergoing mitosis
