Cell Continuity Flashcards
What is cell continuity?
The way in which cells give rise to new cells.
Where are chromosomes found?
In the nucleus.
What are chromosomes composed of?
60% protein and 40% DNA.
How many chromosomes do normal cells have?
46.
Where are genes located?
Alongside chromosomes.
Where do your chromosomes come from?
23 from your mother and 23 from your father.
What is a haploid?
A cell that has one of each type of chromosome.
Give an example of a haploid cell.
Gametes (sperm and egg).
How is haploid represented?
‘n’.
What is a diploid?
A cell with 2 of each type of chromosome.
Give an example of a diploid cell.
Human cheek cells.
How is diploid represented?
‘2n’.
What does the cell cycle describe?
The events in the life of a cell.
What mnemonic is used to remember the 5 stages of the cell cycle?
I (interphase) Party (prophase) Monday (metaphase) And (anaphase) Tuesdays (telophase).
What are the 5 stages of the cell cycle?
Interphase, Prophase, Metaphase, Anaphase, Telophase.
What is interphase?
The period of time when a cell is not dividing.
What happens during interphase?
The cell is not dividing but is very active carrying out protein synthesis, photosynthesis, and respiration.
What occurs during late interphase?
Every chromosome in the cell makes an identical copy of itself (DNA replication).
How long do cells spend in interphase?
90% of their existence.
What two ways can a cell divide during a period of division?
Mitosis and Meiosis.
What is mitosis?
A form of nuclear division in which a nucleus forms 2 nuclei with identical sets of chromosomes.
What is meiosis?
A form of nuclear division in which a daughter nucleus contains half the number of chromosomes as the parent’s nucleus.
Give one example of a human cell not produced by mitosis.
Sex cells / gametes.
What is the function of mitosis in single-celled organisms?
Asexual reproduction.
What is the function of mitosis in multi-celled organisms?
Responsible for growth, renewal, and repairing of cells.
Identify 3 things that happen during prophase.
Nuclear membrane starts to break down, fibres appear in the cytoplasm from the centriole, each chromosome appears as a duplicated strand.
What is the role of the centriole?
Produces fibres.
What is a centromere?
Holds chromosomes together.
Identify 3 things that happen during metaphase.
Chromosomes thicken even more, chromosomes line up across the equator of the cell, fibres attach to each chromosome’s centromere from each side of the cell.
Identify 2 things that happen during anaphase.
Fibres contract, centromeres break and chromosomes are pulled apart.
Identify 2 things that happen during telophase.
2 daughter cells form when the cleavage furrow forms along the cell’s equator, chromosomes elongate within the nucleus.
What happens during telophase in animal and plant cells?
Animal cells: 2 daughter cells form when a cleavage furrow forms. Plant cells: Vesicles of cellulose join to form a cell plate.
What is cancer?
A group of disorders in which certain cells lose their ability to control both the rate of mitosis and how many times it takes place.
What is benign cancer?
They are not life-threatening and do not invade other tissues & the cells stop dividing after some time. eg warts & skin tags.
What is malignant cancer?
Uncontrolled multiplication of abnormal cells, malignant tumours invade other cells and move around the body. Cancer cells divide indefinitely.
What is the movement of malignant cells called?
Metastasis.
What is a cancer-causing gene?
Oncogene.
What is a carcinogen?
Any substance that acts as a ‘cancer-causing agent’.
Give examples of carcinogens.
Cigarette smoke, UV rays, excessive and prolonged alcohol abuse.
What are cancer treatments?
Radiation, chemotherapy, surgery.
What happens to a cell that undergoes meiosis?
It has half the number of chromosomes in the nucleus; a diploid cell becomes a haploid cell.
What is the difference between mitosis and meiosis?
Mitosis produces cells with identical genes and maintains chromosome number; meiosis halves the number of chromosomes.
What is the function of chromosomes?
To carry genes.
What is the function of meiosis?
To produce gametes and variation.
What are the 2 biomolecules produced during interphase?
Protein and nucleic acid (DNA).
What organelle is replicated during interphase?
Centriole.
